106 files changed, 1796 insertions, 0 deletions
diff --git a/2223/CH18/EX18.1/Ex18_1.sav b/2223/CH18/EX18.1/Ex18_1.sav
new file mode 100755
index 000000000..9bd7e8796
--- /dev/null
+++ b/2223/CH18/EX18.1/Ex18_1.sav
diff --git a/2223/CH18/EX18.1/Ex18_1.sce b/2223/CH18/EX18.1/Ex18_1.sce
new file mode 100755
index 000000000..6019def92
--- /dev/null
+++ b/2223/CH18/EX18.1/Ex18_1.sce
@@ -0,0 +1,43 @@
+// scilab Code Exa 18.1 Gas Turbine nozzle row 
+
+T1=600;  // Entry Temperature of the gas in Kelvin
+p1=10; // Inlet Pressure in bar
+gamma_g=1.3;
+delT=32; // Temperature drop of the gas(T1-T2) in K
+cp_g=1.23*1e3; // Specific Heat of gas at Constant Pressure in kJ/(kgK)
+pr1_2=1.3; // pressure ratio(p1/p2)
+T2s=T1/(pr1_2^((gamma_g-1)/gamma_g));
+delTs=T1-T2s;
+
+// part(a) nozzle efficiency
+n_N=delT/delTs;
+disp("%",n_N*100,"(a) nozzle efficiency is")
+
+// part(b)
+disp("(b)(i)for ideal flow:")
+p2=p1/pr1_2;
+h_01=cp_g*T1;
+h2s=cp_g*T2s;
+c_2s=sqrt((h_01-h2s)/0.5);
+disp("m/s",c_2s,"the nozzle exit velocity is")
+R_g=cp_g*((gamma_g-1)/gamma_g);
+M_2s=c_2s/(sqrt(gamma_g*R_g*T2s));
+disp(M_2s,"and the Mach number is")
+disp("(b)(ii)for actual flow:")
+T2=T1-delT;
+a2=sqrt(gamma_g*R_g*T2);
+c_2=sqrt((cp_g*delT)/0.5);
+disp("m/s",c_2,"the nozzle exit velocity is")
+M2=c_2/a2;
+disp(M2,"and the Mach number is")
+
+// part(c) stagnation pressure loss across the nozzle
+p01=p1;
+p02=p2/0.79; // from isentropic gas tables p2/p02=0.79 at gamma=1.3 and M2=0.613
+delp0=p01-p02;
+disp("bar",delp0,"(c)the stagnation pressure loss across the nozzle is")
+
+// part(d) nozzle efficiency based on stagnation pressure loss
+delp=p1-p2;
+n_N_a=1-(delp0/delp);
+disp("%",n_N_a*100,"(d)the nozzle efficiency based on stagnation pressure loss is")
diff --git a/2223/CH18/EX18.10/Ex18_10.sav b/2223/CH18/EX18.10/Ex18_10.sav
new file mode 100755
index 000000000..52ff1d432
--- /dev/null
+++ b/2223/CH18/EX18.10/Ex18_10.sav
diff --git a/2223/CH18/EX18.10/Ex18_10.sce b/2223/CH18/EX18.10/Ex18_10.sce
new file mode 100755
index 000000000..b3df9356c
--- /dev/null
+++ b/2223/CH18/EX18.10/Ex18_10.sce
@@ -0,0 +1,54 @@
+// scilab Code Exa 18.10 Calculation on combined cycle power plant
+
+P_gt=25.845; // Power Output of gas turbine plant in MW
+P_st=21; // Power Output of steam turbine plant in MW
+m_gt=115; // mass flow rate of the exhaust gas in kg/s
+n_T=0.86; // Turbine Efficiency
+gamma_g=1.33;
+R=0.287;
+cp=(gamma_g/(gamma_g-1))*R; // Specific Heat at Constant Pressure in kJ/(kgK)
+T3=1341; // Maximum Temperature in gas turbine in degree K from Ex18.9
+p1=84; // steam Pressure at the entry of steam turbine in bar
+// from steam tables
+t_6s=298.4; // saturation temperature at 84 bar in degree C
+t_5s=t_6s;
+h_6s=1336.1; // from steam table liquid vapour enthalpy at 84 bar
+t6=535;  // steam temperature at the entry of steam turbine in degree C
+T6=t6+273; // in Kelvin
+h_4s=3460; // from mollier diagram at t=535 degree C
+h_7=2050;
+p_c=0.07; // Condenser pressure in bar
+r=8.8502464; //optimum pressure ratio from Ex18.9
+T4=875.92974; //from Ex 18.9
+t4=T4-273; // in degree C
+h_7s=163.4; // Specific Enthalpy of water in kJ/kg
+m_st=P_st*1e3/((h_4s-h_7)*n_T); // mass flow rate of the steam in kg/s
+
+// part(a)Exhaust gas temperature at stack
+t_7=t4-((m_st*(h_4s-h_7s))/(m_gt*cp)); // energy balance for the economiser entry(7') to the superheater exit(4')
+disp("degree celsius",t_7,"(a)Exhaust gas temperature at stack is")
+
+// part(b)mass of steam per kg of gas
+disp("kg",m_st/m_gt,"(b)mass of steam per kg of gas is")
+
+// part(c) Pinch Point(PP)
+t_6=t_7+((m_st*(h_6s-h_7s))/(m_gt*cp)); // energy balance for the economiser
+PP=t_6-t_6s;
+disp("degree celsius",PP,"(c)Pinch Point(PP) is")
+
+// part(d)thermal efficiency of steam turbine plant
+delh4s_7ss=(h_4s-h_7)*n_T;
+n_st=delh4s_7ss/(h_4s-h_7s);
+disp("%",n_st*100,"(d)thermal Efficiency of steam turbine plant is")
+
+// part(e) thermal efficiency of the combined cycle plant
+n_B=0.978; // Assuming Combustion chamber Efficiency
+Qs=102.72554; // heat supplied in the combustion chamber from Ex 18.9
+Qss=Qs/n_B; // power supplied to the combined cycle
+n_gst=(P_gt+P_st)/Qss;
+disp ("%" ,n_gst*100,"(e)thermal Efficiency of combined gas and steam power plant is")
+
+// part(f)the dryness fraction of steam at the turbine exhaust
+x=0.875; // from Mollier diagram at p=0.07 bar
+disp(x,"(f)the dryness fraction of steam at the turbine exhaust is")
+
diff --git a/2223/CH18/EX18.11/Ex18_11.sav b/2223/CH18/EX18.11/Ex18_11.sav
new file mode 100755
index 000000000..48ba54185
--- /dev/null
+++ b/2223/CH18/EX18.11/Ex18_11.sav
diff --git a/2223/CH18/EX18.11/Ex18_11.sce b/2223/CH18/EX18.11/Ex18_11.sce
new file mode 100755
index 000000000..b51e7b9e0
--- /dev/null
+++ b/2223/CH18/EX18.11/Ex18_11.sce
@@ -0,0 +1,55 @@
+// scilab Code Exa 18.11 Calculation on combined cycle power plant
+
+P_gt=25.845; // Power Output of gas turbine plant in MW
+P_st=21; // Power Output of steam turbine plant in MW
+m_gt=115; // mass flow rate of the exhaust gas in kg/s
+n_T=0.86; // Turbine Efficiency
+gamma_g=1.33;
+R=0.287;
+cp=(gamma_g/(gamma_g-1))*R; // Specific Heat at Constant Pressure in kJ/(kgK)
+T3=1341; // Maximum Temperature in gas turbine in degree K from Ex18.9
+p1=84; // steam Pressure at the entry of steam turbine in bar
+// from steam tables
+t_6s=298.4; // saturation temperature at 84 bar in degree C
+h_6s=1336.1; // from steam table liquid vapour enthalpy at 84 bar
+pp(1)=20; // pinch point in degree C
+pp(2)=28.2;
+pp(3)=35;
+
+for i=1:3
+    printf("\nfor PP=%d degree C\n",pp(i))
+t_6=t_6s+pp(i);
+h_4s=3460; // from mollier diagram at t=535 degree C
+h_7=2050;
+p_c=0.07; // Condenser pressure in bar
+T4=875.92974; //from Ex 18.9
+t4=T4-273; // in degree C
+h_7s=163.4; // Specific Enthalpy of water in kJ/kg
+
+// part(a)steam flow per kg of gas
+m_st_gt=cp*(t4-t_6)/(h_4s-h_6s); // steam flow per kg of gas
+disp("kg",m_st_gt,"(a)steam flow per kg of gas is")
+
+// part(b)Exhaust gas temperature at stack
+t_7=t_6-((m_st_gt*(h_6s-h_7s))/(cp)); // energy balance for the economiser entry(7') to the superheater exit(4')
+disp("degree celsius",t_7,"(b)Exhaust gas temperature at stack is")
+
+// part(c)steam turbine plant output
+h_7ss=2247;
+P_st=m_st_gt*m_gt*(h_4s-h_7ss);
+disp("MW",P_st/1e3,"(c)Power output of the steam turbine plant is")
+
+// part(d)thermal efficiency of steam turbine plant
+delh4s_7ss=(h_4s-h_7)*n_T;
+n_st=delh4s_7ss/(h_4s-h_7s);
+disp("%",n_st*100,"(d)thermal Efficiency of steam turbine plant is")
+
+// part(e) thermal efficiency of the combined cycle plant
+n_B=0.978; // Assuming Combustion chamber Efficiency
+Qs=102.72554; // heat supplied in the combustion chamber from Ex 18.9
+Qss=Qs/n_B; // power supplied to the combined cycle
+n_gst=(P_gt+(P_st*1e-3))/Qss;
+disp("%",n_gst*100,"(e)thermal Efficiency of combined gas and steam power plant is")
+end
+
+disp("Comment: Error in Textbook, Answers vary due to Round-off Errors")
diff --git a/2223/CH18/EX18.12/Ex18_12.sav b/2223/CH18/EX18.12/Ex18_12.sav
new file mode 100755
index 000000000..4bf49a244
--- /dev/null
+++ b/2223/CH18/EX18.12/Ex18_12.sav
diff --git a/2223/CH18/EX18.12/Ex18_12.sce b/2223/CH18/EX18.12/Ex18_12.sce
new file mode 100755
index 000000000..8645e5951
--- /dev/null
+++ b/2223/CH18/EX18.12/Ex18_12.sce
@@ -0,0 +1,35 @@
+// scilab Code Exa 18.12 turbo prop Gas Turbine Engine
+
+Ti=268.65; // in Kelvin
+n_C=0.8; // Compressor Efficiency
+c1=85; // entry velocity in m/s
+m=50; // mass flow rate of air in kg/s
+R=287;
+gamma=1.4; // Specific Heat Ratio
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+u=500/3.6; // speed of a turbo prop aircraft in m/s
+delT=225; // temperature rise through the compressor(T02-T01) in K
+pi=.701; // Initial Pressure in bar
+n_D=0.88; // inlet diffuser efficiency
+a_i=sqrt(gamma*R*Ti);
+Mi=u/a_i;
+Toi_i=1/0.965; // (Toi/Ti)from isentropic flow gas tables at Mi and gamma values
+T01=Ti*Toi_i;
+T1=T01-(0.5*(c1^2)/(cp*1e3));
+
+//part(a)
+T1s_i=1+n_D*((T1/Ti)-1); // (T1s/Ti)isentropic temperature ratio through the diffuser
+p1_i=T1s_i^(gamma/(gamma-1)); // (p1s/pi)isentropic pressure ratio
+p1=p1_i*pi;
+delp_D=p1-pi;
+disp("bar",delp_D,"(a)isentropic pressure rise through the diffuser is")
+
+// part(b) compressor pressure ratio
+T02s=T01+(delT*n_C);
+r_oc=(T02s/T01)^(gamma/(gamma-1)); //compressor pressure ratio(p02/p01)
+disp(r_oc,"(b)compressor pressure ratio is")
+
+// part(c)
+P=m*cp*delT;
+disp("MW",P*1e-3,"(c)power required to drive the compressor is")
+
diff --git a/2223/CH18/EX18.13/Ex18_13.sav b/2223/CH18/EX18.13/Ex18_13.sav
new file mode 100755
index 000000000..9641ce3e5
--- /dev/null
+++ b/2223/CH18/EX18.13/Ex18_13.sav
diff --git a/2223/CH18/EX18.13/Ex18_13.sce b/2223/CH18/EX18.13/Ex18_13.sce
new file mode 100755
index 000000000..9169fc8bd
--- /dev/null
+++ b/2223/CH18/EX18.13/Ex18_13.sce
@@ -0,0 +1,55 @@
+// scilab Code Exa 18.13 Turbojet Gas Turbine Engine
+
+T1=223.15; // in Kelvin
+n_C=0.75; // Compressor Efficiency
+c1=85; // entry velocity in m/s
+m=50; // mass flow rate of air in kg/s
+R=287;
+n_B=0.98; // Combustion chamber Efficiency
+Qf=43*1e3; // Calorific Value of fuel in kJ/kg;
+T03=1220;  // Turbine inlet stagnation temp in Kelvin
+n_T=0.8; // Turbine Efficiency
+gamma=1.4; // Specific Heat Ratio
+n_m=0.98; // Mechanical efficiency
+sigma=0.5; // flight to jet speed ratio(u/ce)
+n_N=0.98; // exhaust nozzle efficiency
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+u=886/3.6; // flight speed of a turbo prop aircraft in m/s
+delT=200; // temperature rise through the compressor(T02-T01) in K
+pi=.701; // Initial Pressure in bar
+n_D=0.88; // inlet diffuser efficiency
+a1=sqrt(gamma*R*T1);
+M1=u/a1; // Mach number at the compressor inlet
+T1_01=0.881; // (T1/T01)from isentropic flow gas tables at M1 and gamma values
+T01=T1/T1_01;
+T1=T01-(0.5*(c1^2)/(cp*1e3));
+
+// part(a) compressor pressure ratio
+T02s=T01+(delT*n_C);
+r_oc=(T02s/T01)^(gamma/(gamma-1)); //compressor pressure ratio(p02/p01)
+disp(r_oc,"(a)compressor pressure ratio is")
+
+// part(b)
+T02=T01+delT;
+f=((cp*T03)-(cp*T02))/((Qf*n_B)-(cp*T03)); // f=(ma/mf);energy balance in the combustion chamber 
+disp(1/f,"(b)Air-Fuel Ratio is")
+
+// part(c) turbine pressure ratio
+// turbine power input P_T=n_m*(ma+mf)*cp*(T03-T01)
+// power input to the compressor P_C=ma*cp*(T02-T01)
+T04s=T03-(delT/(n_m*n_T*(1+f))); // from energy balance P_T=P_C
+r_ot=(T03/T04s)^(gamma/(gamma-1)); //turbine pressure ratio(p03/p04)
+disp(r_ot,"(c)turbine pressure ratio is")
+
+// part(d)exhaust nozzle pressure ratio
+ce=u/sigma; // jet velocity at the exit of the exhaust nozzle
+T04=T03-(delT/(n_m*(1+f)));
+Te=T04-(0.5*(ce^2)/(cp*1e3));
+Tes=T04-((T04-Te)/n_N);
+r_N=(T04/Tes)^(gamma/(gamma-1)); //exhaust nozzle pressure ratio(p04/pe)
+disp(r_N,"(d)exhaust nozzle pressure ratio is")
+ae=sqrt(gamma*R*Te);
+Me=ce/ae; // Mach number
+disp(Me,"and the Mach Number is")
+
+
diff --git a/2223/CH18/EX18.15/Ex18_15.sav b/2223/CH18/EX18.15/Ex18_15.sav
new file mode 100755
index 000000000..17bd16a24
--- /dev/null
+++ b/2223/CH18/EX18.15/Ex18_15.sav
diff --git a/2223/CH18/EX18.15/Ex18_15.sce b/2223/CH18/EX18.15/Ex18_15.sce
new file mode 100755
index 000000000..f41e5fdbb
--- /dev/null
+++ b/2223/CH18/EX18.15/Ex18_15.sce
@@ -0,0 +1,35 @@
+// scilab code Exa 18.15 Impulse Steam Turbine 3000 rpm
+
+P=500; // Power Output in kW
+u=100; // peripheral speed of the rotor blades in m/s
+cy2=200; // whirl component of the absolute velocity at entry of the rotor
+cy3=0; // whirl component of the absolute velocity at exit of the rotor
+alpha2=65; // nozzle angle at exit
+n_st=0.69; // isentropic stage efficiency
+p2=8; // steam pressure at the exit of the first stage in bar
+t2=200; // steam temperature at the exit of the first stage in degree C
+N=3e3; // rotor Speed in RPM
+
+//part(a)Mean diameter of the stage
+d=u*60/(%pi*N);
+disp("m",d,"(a)Mean diameter of the stage is")
+
+// part(b)mass flow rate of the steam
+w_st=2*(u^2)*1e-3; // specific work
+m=P/w_st;
+disp("kg/s",m,"(b)mass flow rate of the steam is")
+
+// part(c)isentropic enthalpy drop
+delh_s=w_st/n_st;
+disp("kJ/kg",delh_s,"(c)isentropic enthalpy drop is")
+
+// part(d)rotor blade angles
+cx=cy2/(tand(alpha2));
+beta3=atand(u/cx);
+disp("degree",beta3,"(d)the rotor blade angles are beta2=beta3=")
+
+// part(e)blade height at the nozzle exit
+v_s2=0.2608; // from steam tables at p2=8bar and t2=200 degree C
+Q=m*v_s2;
+h=Q/(cx*%pi*d);
+disp("m",h,"(e)blade height at the nozzle exit is")
diff --git a/2223/CH18/EX18.16/Ex18_16.sav b/2223/CH18/EX18.16/Ex18_16.sav
new file mode 100755
index 000000000..bb522b9f8
--- /dev/null
+++ b/2223/CH18/EX18.16/Ex18_16.sav
diff --git a/2223/CH18/EX18.16/Ex18_16.sce b/2223/CH18/EX18.16/Ex18_16.sce
new file mode 100755
index 000000000..fa8bc7045
--- /dev/null
+++ b/2223/CH18/EX18.16/Ex18_16.sce
@@ -0,0 +1,33 @@
+// scilab Code Exa 18.16 large Centrifugal pump 1000rpm
+
+N=1e3; // rotor Speed in RPM
+H=45; // height in m
+ro=1e3;
+g=9.81; // Gravitational acceleration in m/s^2
+n_o=0.75; // overall Efficiency of the drive
+dr=2; // diameter ratio(d2/d1)
+phi=0.35; // flow coefficient(cr2/u2)
+Q=2.5; // discharge in m3/s
+
+//part(a)Power required to drive the pump
+P=(ro*Q*g*H)/(n_o);
+disp("kW",P*1e-3,"(a)Power required to drive the pump is")
+
+// part(b) impeller diameters at entry and exit
+u2=sqrt(g*H);
+w_p=u2^2;
+d2=u2*60/(%pi*N);
+disp("cm",d2*1e2,"(b)the impeller diameter at exit is")
+d1=d2/2;
+disp("cm",d1*1e2,"and the impeller diameter at entry is")
+
+//part(c) impeller width
+c_r2=phi*u2;
+b=Q/(c_r2*%pi*d2);
+disp("cm",b*1e2,"(c)the impeller width is")
+
+// part(d)impeller blade angle at the entry
+c_r1=Q/(b*%pi*d1);
+u1=u2/dr;
+beta1=atand(c_r1/u1);
+disp("degree",beta1,"(d)the impeller blade angle at the entry beta1=")
diff --git a/2223/CH18/EX18.17/Ex18_17.sav b/2223/CH18/EX18.17/Ex18_17.sav
new file mode 100755
index 000000000..6a90f531c
--- /dev/null
+++ b/2223/CH18/EX18.17/Ex18_17.sav
diff --git a/2223/CH18/EX18.17/Ex18_17.sce b/2223/CH18/EX18.17/Ex18_17.sce
new file mode 100755
index 000000000..ec87bb2c5
--- /dev/null
+++ b/2223/CH18/EX18.17/Ex18_17.sce
@@ -0,0 +1,45 @@
+// scilab Code Exa 18.17 three stage steam turbine
+
+t1=250;  // Initial Temperature in degree C
+n_T=0.75; // overall Efficiency of the turbine
+p1=10; //Initial Pressure in bar
+n_m=0.98; // Mechanical Efficiency
+m=5;
+N=1e3; // rotor Speed in RPM
+H=45; // height in m
+ro=1e3;
+g=9.81; // Gravitational acceleration in m/s^2
+Q=2.5; // discharge in m3/s
+
+P=(ro*Q*g*H)/(n_T);
+delh_T=P/(m*n_m*1e3);
+delh_st=delh_T/3;
+delh1_4ss=delh_T/n_T;
+
+//part(a)steam conditions
+h1=2940; // from Mollier diagram
+disp("(a)steam conditions at the turbine exit are:")
+h_4ss=h1-delh1_4ss;
+p4=1.2; // in bar
+disp("bar",p4,"pressure:")
+h4=2640;
+x4=0.98;
+t4=104.8; // in degree C
+disp("degree C",t4,"temperature:")
+disp(x4,"the dryness fraction is:")
+
+// part(b)stage Efficiencies
+h2=h1-delh_st;
+p2=5;
+h3=h2-delh_st;
+p3=2.5;
+h4=h3-delh_st;
+h2s=2795;
+h3s=2705;
+h4s=2605;
+n_st1=delh_st/(h1-h2s);
+n_st2=delh_st/(h2-h3s);
+n_st3=delh_st/(h3-h4s);
+disp ("%",n_st1*100,"(b)Efficiency of the first stage is")
+disp ("%",n_st2*100,"Efficiency of the second stage is")
+disp ("%",n_st3*100,"Efficiency of the third stage is")
diff --git a/2223/CH18/EX18.18/Ex18_18.sav b/2223/CH18/EX18.18/Ex18_18.sav
new file mode 100755
index 000000000..0cd6376c3
--- /dev/null
+++ b/2223/CH18/EX18.18/Ex18_18.sav
diff --git a/2223/CH18/EX18.18/Ex18_18.sce b/2223/CH18/EX18.18/Ex18_18.sce
new file mode 100755
index 000000000..02d6b436e
--- /dev/null
+++ b/2223/CH18/EX18.18/Ex18_18.sce
@@ -0,0 +1,27 @@
+// scilab Code Exa 18.18 Ljungstrom turbine 3600 rpm
+
+d1=0.92; // inner diameter of the impeller in m
+d2=1; // outer diameter of the impeller in m
+N=3.6e3; // rotor Speed in RPM
+aplha_1=20; // blade exit angle in degree
+p2=0.1; //exit Pressure of steam in bar
+x2=0.88; // dryness fraction at exit
+n_st=0.83; // stage Efficiency
+u1=%pi*d1*N/60;
+u2=%pi*d2*N/60;
+
+//part(a)power developed
+sigma=cosd(aplha_1)/2;
+w_st=u1^2+u2^2;
+disp("kW/(kg/s)",w_st*1e-3,"(a)power developed per unit flow rate is")
+
+//part(b) isentropic enthalpy drop
+delh_s=w_st/n_st;
+disp("kJ/kg",delh_s*1e-3,"(b)isentropic enthalpy drop is")
+
+// part(c)steam conditions at entry
+disp("(c)steam conditions at entry are:")
+p1=0.18; // in bar
+disp("bar",p1,"pressure:")
+x1=0.9;
+disp(x1,"the dryness fraction is:")
diff --git a/2223/CH18/EX18.19/Ex18_19.sav b/2223/CH18/EX18.19/Ex18_19.sav
new file mode 100755
index 000000000..8977a49e7
--- /dev/null
+++ b/2223/CH18/EX18.19/Ex18_19.sav
diff --git a/2223/CH18/EX18.19/Ex18_19.sce b/2223/CH18/EX18.19/Ex18_19.sce
new file mode 100755
index 000000000..9e580fc06
--- /dev/null
+++ b/2223/CH18/EX18.19/Ex18_19.sce
@@ -0,0 +1,46 @@
+// scilab Code Exa 18.19 blower type wind tunnel 
+
+T01=310;  // in Kelvin
+p01=1.013; //  Initial Pressure in bar
+n_n=0.96; // nozzle efficiency
+n_c=0.78; // compressor efficiency
+Ma(1)=0.5;
+Ma(2)=0.9;
+pi(1)=0.837; // from isentropic flow gas tables
+pi(2)=0.575;
+gamma=1.4; // Specific Heat Ratio
+R=287;
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+
+for i=1:2
+printf("when Ma=%f",Ma(i))
+//part(a)
+Ms=((n_n/(Ma(i)^2))-(((gamma-1)/2)*(1-n_n)))^(-1/2);
+disp(Ms,"(a)Mach number for isentropic flow is")
+
+// part(b)
+p0e=1;
+p_r0(i)=p0e/pi(i);
+disp(p_r0(i),"(b)pressure ratio of the compressor is")
+
+// part(c)
+delT0e_0i=((p_r0(i)^((gamma-1)/gamma))-1)/n_c;
+T0e=T01+(T01*delT0e_0i);
+delT0e_t=n_n*(1-(p_r0(i)^((1-gamma)/gamma)))*T0e;
+T_t=T0e-delT0e_t;
+disp("K",T_t,"(c)the test section temperature is")
+a_t=sqrt(gamma*R*T_t);
+c_t=Ma(i)*a_t;
+disp("m/s",c_t,"and the test section velocity is")
+
+// part(d)
+ro_t=p01*1e5/(R*T_t);
+A_t=0.17*0.15;
+m=ro_t*A_t*c_t;
+disp("kg/s",m,"(d)mass flow rate is")
+
+// part(e)
+P(1)=m*cp*(T0e-T01);
+P(2)=m*cp*(T_t-T01);
+disp("kW",P(i),"(e)power required for the compressor is")
+end
diff --git a/2223/CH18/EX18.2/Ex18_2.sav b/2223/CH18/EX18.2/Ex18_2.sav
new file mode 100755
index 000000000..14e8076cc
--- /dev/null
+++ b/2223/CH18/EX18.2/Ex18_2.sav
diff --git a/2223/CH18/EX18.2/Ex18_2.sce b/2223/CH18/EX18.2/Ex18_2.sce
new file mode 100755
index 000000000..4796516bf
--- /dev/null
+++ b/2223/CH18/EX18.2/Ex18_2.sce
@@ -0,0 +1,38 @@
+// scilab Code Exa 18.2 Steam Turbine nozzle 
+
+t1=550;  // Entry Temperature in Kelvin
+p1=170; // Inlet Pressure in bar
+p2=120.7; // Exit Pressure in bar
+d=1; // Mean Blade ring diameter in m
+alpha_2=70;  // nozzle angle in degree
+gamma_g=1.3; // for superheated steam
+R=0.5*1e3; // in J/kgK
+m=280; // in kg/s
+
+// part(a) exit velocity c2 of steam
+h1=3440; // from superheated steam tables at p1 and t1
+h2=3350; // at p2
+t2=503; // at p2 in degree C
+v_s2=0.0268; // Specific Volume at p2 in m3/kg
+c_2=sqrt((h1-h2)*1e3/0.5);
+disp("m/s",c_2,"(a)the nozzle exit velocity is")
+
+// part(b)
+T2=t2+273;
+a2=sqrt(gamma_g*R*T2);
+M2=c_2/a2;
+disp(M2,"(b)and the exit Mach number is")
+
+// part(c)
+cx=c_2*cosd(alpha_2);
+h=m*v_s2/(%pi*cx*d);
+disp("cm",h*1e2,"(c)nozzle blade height at exit is")
+
+T2s=0.87*(t1+273); // T2s/T1=0.87 from gas tables
+p2s=0.546*p1; // p2s/p1=0.546 from gas tables
+vs_s=0.031; // from steam tables
+a_s=sqrt(gamma_g*R*T2s);
+disp("m/s",a_s,"the corresponding nozzle exit velocity is")
+cx_s=a_s*cosd(alpha_2);
+m_max=cx_s*%pi*d*h/(vs_s);
+disp("kg/s",m_max,"the maximum possible mass flow rate is")
diff --git a/2223/CH18/EX18.20/Ex18_20.sav b/2223/CH18/EX18.20/Ex18_20.sav
new file mode 100755
index 000000000..1783b434b
--- /dev/null
+++ b/2223/CH18/EX18.20/Ex18_20.sav
diff --git a/2223/CH18/EX18.20/Ex18_20.sce b/2223/CH18/EX18.20/Ex18_20.sce
new file mode 100755
index 000000000..fc5844b8b
--- /dev/null
+++ b/2223/CH18/EX18.20/Ex18_20.sce
@@ -0,0 +1,37 @@
+// scilab Code Exa 18.20 Calculation on an axial turbine cascade
+
+beta1=35; //  blade angle at entry
+beta2=55; // blade angle at exit
+i(1)=5; // incidence
+i(2)=10;
+i(3)=15;
+i(4)=20;
+delta=2.5; // deviation
+alpha2=beta2-delta; // air angle at exit
+a_r=2.5; // aspect ratio(h/l)
+
+n=4;
+for m=1:n
+//part(a)
+printf("\nfor incidence=%d\n",i(m))
+alpha1=beta1+i(m); // air angle at entry
+ep=alpha1+alpha2; // deflection angle
+disp("degree",ep,"(a)flow deflection is")
+p_c=0.505; //(s/l)
+
+//part(b) loss coefficient from Hawthorne relations
+
+z_p=0.025*(1+((ep/90)^2)); // Hawthorne's relation
+disp (z_p,"(b)the profile loss coefficient from Hawthorne relation is")
+z=(1+(3.2/a_r))*z_p; // the total cascade loss coefficient
+disp (z,"and the total loss coefficient is")
+Y=z; 
+
+// part(c)drag and lift coefficients
+alpham=atand((0.5*(tand(alpha2)-tand(alpha1))));
+C_D=p_c*Y*((cosd(alpham)^3)/(cosd(alpha2)^2));
+disp (C_D,"(c)the drag coefficient is")
+
+C_L=(2*p_c*(tand(alpha1)+tand(alpha2))*cosd(alpham))+(C_D*tand(alpham));
+disp (C_L,"and the Lift coefficient is")
+end
diff --git a/2223/CH18/EX18.21/Ex18_21.sav b/2223/CH18/EX18.21/Ex18_21.sav
new file mode 100755
index 000000000..0e53cfe52
--- /dev/null
+++ b/2223/CH18/EX18.21/Ex18_21.sav
diff --git a/2223/CH18/EX18.21/Ex18_21.sce b/2223/CH18/EX18.21/Ex18_21.sce
new file mode 100755
index 000000000..222160efb
--- /dev/null
+++ b/2223/CH18/EX18.21/Ex18_21.sce
@@ -0,0 +1,43 @@
+// scilab Code Exa 18.21 low reaction turbine stage
+
+Beta2=35; // rotor blade air angle in degree
+alpha1=0; // fixed blade air angle in degree
+alpha2=65;
+beta3=52.5;
+I(1)=0; // incidence angle
+I(2)=5;
+I(3)=10;
+I(4)=15;
+I(5)=20;
+a_r=2.5; // aspect ratio(h/l)
+
+for i=1:5
+disp("degree",I(i),"when incidence=")
+beta2(i)=Beta2+I(i); // beta2 varies with incidence
+
+//part(a)
+phi=cosd(alpha2)*cosd(beta2(i))/(sind(alpha2-beta2(i)));
+ep=alpha1+alpha2; // deflection angle
+disp(phi,"(a)flow coefficient is")
+p_c=0.505; //pitch-chord ratio(s/l)
+
+//part(b)blade to gas speed ratio
+sigma=sind(alpha2-beta2(i))/(cosd(beta2(i)));
+disp(sigma,"(b)blade to gas speed ratio is")
+z_N=2.28*0.025*(1+((ep/90)^2)); // Hawthorne's relation
+
+// part(c)degree of reaction
+R=0.5*phi*(tand(beta3)-tand(beta2(i)));
+disp("%",R*1e2,"(c)the degree of reaction is")
+
+// part(d)total-to-total efficiency
+e_R=beta2(i)+beta3; // Rotor deflection angle
+zeeta_p_R=0.025*(1+((e_R/90)^2)); // profile loss coefficient for rotor
+zeeta_R=(1+(3.2/a_r))*zeeta_p_R; // total loss coefficient for rotor
+a=(zeeta_R*(secd(beta3)^2))+(z_N*(secd(alpha2)^2));
+b=phi*(tand(alpha2)+tand(beta3))-1;
+n_tt=inv(1+(0.5*(phi^2)*(a/b)));
+disp("%",n_tt*1e2,"(d)total-to-total efficiency is")
+
+end
+
diff --git a/2223/CH18/EX18.22/Ex18_22.sav b/2223/CH18/EX18.22/Ex18_22.sav
new file mode 100755
index 000000000..2fe4d5990
--- /dev/null
+++ b/2223/CH18/EX18.22/Ex18_22.sav
diff --git a/2223/CH18/EX18.22/Ex18_22.sce b/2223/CH18/EX18.22/Ex18_22.sce
new file mode 100755
index 000000000..e42240371
--- /dev/null
+++ b/2223/CH18/EX18.22/Ex18_22.sce
@@ -0,0 +1,29 @@
+// scilab Code Exa 18.22 Isentropic or Stage Terminal Velocity for Turbines 
+
+T01=1273;  // in Kelvin
+funcprot(0);
+p01=5; //  Initial Pressure in bar
+p02=3.5; //  exit gas Pressure in bar
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+gamma=1.4; // Specific Heat Ratio
+m=28; // mass flow rate of the gas in kg/s
+n_tt=0.84; // stage efficiency
+shi=1.7; // stage loading coefficient
+pr_0=p01/p02;
+delh01_03ss=cp*T01*(1-(pr_0^((1-gamma)/gamma)));
+
+//part(a)stage terminal velocity
+c0=sqrt(2*delh01_03ss*1e3);
+disp("m/s",c0,"(a)stage terminal velocity is")
+
+// part(b)isentropic blade to gas speed ratio
+sigma_s=sqrt(0.5*n_tt/shi);
+disp(sigma_s,"(b)the isentropic blade to gas speed ratio is")
+
+//part(c) peripheral speed of the rotor
+u=sigma_s*c0;
+disp("m/s",u,"(c)peripheral speed of the rotor is")
+
+//part(d) the power developed
+P=m*n_tt*delh01_03ss;
+disp("MW",P*1e-3,"(d) the power developed is")
diff --git a/2223/CH18/EX18.23/Ex18_23.sav b/2223/CH18/EX18.23/Ex18_23.sav
new file mode 100755
index 000000000..8726c784d
--- /dev/null
+++ b/2223/CH18/EX18.23/Ex18_23.sav
diff --git a/2223/CH18/EX18.23/Ex18_23.sce b/2223/CH18/EX18.23/Ex18_23.sce
new file mode 100755
index 000000000..25c0e7072
--- /dev/null
+++ b/2223/CH18/EX18.23/Ex18_23.sce
@@ -0,0 +1,7 @@
+// scilab Code Exa 18.23 axial compressor stage efficiency 
+
+R=0.5; // Degree of reaction
+n_R=0.849; // efficiency of rotor blade row
+n_D=0.849; // efficiency of diffuser blade row
+n_st=R*n_R+(1-R)*n_D;
+disp("%",n_st*1e2,"the value of stage efficiency is")
diff --git a/2223/CH18/EX18.24/Ex18_24.sav b/2223/CH18/EX18.24/Ex18_24.sav
new file mode 100755
index 000000000..d74e6eadb
--- /dev/null
+++ b/2223/CH18/EX18.24/Ex18_24.sav
diff --git a/2223/CH18/EX18.24/Ex18_24.sce b/2223/CH18/EX18.24/Ex18_24.sce
new file mode 100755
index 000000000..097fe2599
--- /dev/null
+++ b/2223/CH18/EX18.24/Ex18_24.sce
@@ -0,0 +1,17 @@
+// scilab Code Exa 18.24 Calculation on an axial compressor cascade 
+
+beta1=51;
+beta2=9;
+alpha_1=7;  //  air angle at rotor and stator exit
+u=100; // test section velocity of air in m/s
+cx=u/(tand(alpha_1)+tand(beta1));
+w1=cx/cosd(beta1);
+alpha2=atand(tand(alpha_1)+tand(beta1)-tand(beta2))
+c2=cx/cosd(alpha2);
+Y_D=0.0367; // loss coefficient for diffuser blade row
+Y_R=0.0393; // loss coefficient for rotor blade row
+z_R=Y_R*((w1/u)^2);
+z_D=Y_D*((c2/u)^2);
+phi=cx/u;
+n_st=1-(0.5*phi*(z_D*(secd(alpha2)^2)+z_R*(secd(beta1)^2))/(tand(beta1)-tand(beta2)));
+disp("%",n_st*1e2,"the value of stage efficiency is")
diff --git a/2223/CH18/EX18.25/Ex18_25.sav b/2223/CH18/EX18.25/Ex18_25.sav
new file mode 100755
index 000000000..669d86539
--- /dev/null
+++ b/2223/CH18/EX18.25/Ex18_25.sav
diff --git a/2223/CH18/EX18.25/Ex18_25.sce b/2223/CH18/EX18.25/Ex18_25.sce
new file mode 100755
index 000000000..c6627cef7
--- /dev/null
+++ b/2223/CH18/EX18.25/Ex18_25.sce
@@ -0,0 +1,74 @@
+// scilab Code Exa 18.25 Calculation on two stage axial compressor 
+
+T01=310;  // in Kelvin
+funcprot(0);
+gamma=1.4;
+p01=1.02; //  Initial Pressure in bar
+pr_o=2;
+pr_o1=1.5;
+N=7.2e3; // rotor Speed in RPM
+d=65/100; // Mean Blade ring diameter in m
+h=10/100; // blade height at entry in m
+n_p=0.9; // polytropic efficiency
+wdf=0.87; // work-done factor
+m=25; //  in kg/s 
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+R=287;
+T01(1)=T01;
+// part(a) stage pressure ratio
+pr_o2=pr_o/pr_o1;
+disp(pr_o2,"(a)pressure ratio developed by the 2nd stage is")
+
+//part(b) stage efficiency
+n=(gamma-1)/gamma;
+n_st1=((pr_o1^n)-1)/((pr_o1^(n/n_p))-1);
+disp("%",n_st1*1e2,"(b)stage efficiency for the stage 1 is")
+n_st2=((pr_o2^n)-1)/((pr_o2^(n/n_p))-1);
+disp("%",n_st2*1e2,"and stage efficiency for the stage 2 is")
+// part(c)power required to drive the compressor
+T02=T01*(pr_o1^((gamma-1)/gamma));
+P1=m*cp*(T02-T01)/n_st1;
+disp("kW",P1,"(c) power required for the 1st stage is")
+T02s=T01+(T01*(pr_o1^((gamma-1)/gamma)-1)/n_st1);
+P2=m*cp*T02s*(pr_o2^((gamma-1)/gamma)-1)/n_st2;
+disp("kW",P2,"and power required for the 2nd stage is")
+
+
+
+// part(d) air angles of the rotors and stators
+A1=%pi*d*h;
+ro_01=(p01*1e5)/(R*T01);
+cx=m/(ro_01*A1);
+    T1=T01-((cx^2)/(2*cp*1e3));
+    p1=p01*((T1/T01)^(1/((gamma-1)/gamma)));
+ro1=(p1*1e5)/(R*T1);
+cx_new=m/(ro1*A1);
+c1=cx_new;
+disp("for first stage")
+u=%pi*d*N/60;
+beta1=atand(u/c1);
+disp("degree",beta1,"beta1=")
+wst1=cp*(T02-T01)*1e3/n_st1;
+cy2=wst1/(wdf*u);
+alpha2=atand(cy2/cx_new);
+disp("degree",alpha2,"alpha2=")
+beta2=atand((u/cx_new)-tand(alpha2));
+disp("degree",beta2,"beta2=")
+R=cx_new*(tand(beta1)+tand(beta2))*100/(2*u);
+disp("%",R,"degree of reaction for the first stage is")
+
+T01_II=T02s;
+disp("for second stage")
+T02_II=T01_II*(pr_o2^((gamma-1)/gamma));
+wst2=cp*1e3*(T02_II-T01_II)/n_st2;
+alpha1s=beta2;
+cy1s=cx_new*tand(alpha1s);
+cy2s=(cy1s)+(wst2/(wdf*u));
+alpha2s=atand(cy2s/cx_new);
+disp("degree",alpha2s,"alpha2s=")
+beta1s=atand((u-cy1s)/cx_new);
+disp("degree",beta1s,"beta1s=")
+beta2s=atand((u-cy2s)/cx_new);
+disp("degree",beta2s,"beta2s=")
+R_II=cx_new*(tand(beta1s)+tand(beta2s))*100/(2*u);
+disp("%",R_II,"Degree of Reaction for the second stage is")
diff --git a/2223/CH18/EX18.26/Ex18_26.sav b/2223/CH18/EX18.26/Ex18_26.sav
new file mode 100755
index 000000000..8d52b7e96
--- /dev/null
+++ b/2223/CH18/EX18.26/Ex18_26.sav
diff --git a/2223/CH18/EX18.26/Ex18_26.sce b/2223/CH18/EX18.26/Ex18_26.sce
new file mode 100755
index 000000000..559dbb57e
--- /dev/null
+++ b/2223/CH18/EX18.26/Ex18_26.sce
@@ -0,0 +1,26 @@
+// scilab Code Exa 18.24 Calculation on an axial compressor cascade 
+
+R=0.5906; // Degree of reaction
+beta1=66;
+beta2=22;
+alpha2=61;
+p_R=0.865; // pitch-chord ratio(s/l) for rotor
+p_S=0.963; // pitch-chord ratio(s/l) for stator
+alpha_3=beta2; //  air angle at rotor and stator exit
+u=100; // test section velocity of air in m/s
+Y_D=0.077; // profile loss coefficient for stator blade row
+Y_R=0.08; // loss coefficient for rotor blade row
+beta_m=atand(0.5*(tand(beta1)+tand(beta2)));
+C_D_R=p_R*Y_R*(cosd(beta_m)^3)/(cosd(beta1)^2);
+C_L_R=(2*p_R*(tand(beta1)-tand(beta2))*cosd(beta_m))-(C_D_R*tand(beta_m));
+n_R=1-(2*C_D_R/(C_L_R*sind(2*beta_m)));
+disp("%",n_R*1e2,"the value of rotor cascade efficiency is")
+
+alpham=atand(0.5*(tand(alpha2)+tand(alpha_3)));
+C_D_S=p_S*Y_D*(cosd(alpham)^3)/(cosd(alpha2)^2);
+C_L_S=(2*p_S*(tand(alpha2)-tand(alpha_3))*cosd(alpham))-(C_D_S*tand(alpham));
+n_D=1-(2*C_D_S/(C_L_S*sind(2*alpham)));
+disp("%",n_D*1e2,"the value of diffuser cascade efficiency is")
+
+n_st=R*n_R+(1-R)*n_D;
+disp("%",n_st*1e2,"the value of stage efficiency is")
diff --git a/2223/CH18/EX18.27/Ex18_27.sav b/2223/CH18/EX18.27/Ex18_27.sav
new file mode 100755
index 000000000..d965a7217
--- /dev/null
+++ b/2223/CH18/EX18.27/Ex18_27.sav
diff --git a/2223/CH18/EX18.27/Ex18_27.sce b/2223/CH18/EX18.27/Ex18_27.sce
new file mode 100755
index 000000000..49314758b
--- /dev/null
+++ b/2223/CH18/EX18.27/Ex18_27.sce
@@ -0,0 +1,33 @@
+// scilab Code Exa 18.27 Isentropic Flow-centrifugal Air compressor 
+
+T01=335;  // in Kelvin
+p01=1.02; //  Initial Pressure in bar
+beta1=61.4; // air angle at the inlet of axial inducer blades
+gamma=1.4;
+d1=0.175; // Mean Blade ring diameter at entry
+d2=0.5; // impeller diameter at exit
+cp=1005; // Specific Heat at Constant Pressure in J/(kgK)
+A1=0.0412; // Area of cross section at the impeller inlet
+R=287;
+
+N(1)=5700; // rotor Speed in RPM
+N(2)=6200;
+N(3)=6700;
+N(4)=7200;
+for i=1:4
+printf("\n for N=%d rpm\n\n",N(i))
+u1=%pi*d1*N(i)/60;
+u2=%pi*d2*N(i)/60;
+c1=u1*tand(beta1);
+T1=T01-((c1^2)/(2*cp));
+p1=p01*((T1/T01)^(gamma/(gamma-1)));
+ro1=(p1*1e5)/(R*T1);
+pr0=((1+(u2^2/(cp*T01)))^(gamma/(gamma-1)));
+disp(pr0,"(a)pressure ratio is")
+m=ro1*A1*c1;
+disp("kg/s",m,"(b)mass flow rate of air is")
+T02=T01*(pr0^((gamma-1)/gamma));
+P=m*cp*(T02-T01);
+disp("kW",P*1e-3,"(c)Power required to drive the compressor P=")
+end
+
diff --git a/2223/CH18/EX18.28/Ex18_28.sav b/2223/CH18/EX18.28/Ex18_28.sav
new file mode 100755
index 000000000..586958caf
--- /dev/null
+++ b/2223/CH18/EX18.28/Ex18_28.sav
diff --git a/2223/CH18/EX18.28/Ex18_28.sce b/2223/CH18/EX18.28/Ex18_28.sce
new file mode 100755
index 000000000..5de7977fd
--- /dev/null
+++ b/2223/CH18/EX18.28/Ex18_28.sce
@@ -0,0 +1,36 @@
+// scilab Code Exa 18.28 centrifugal Air compressor 
+T01=335;  // in Kelvin
+p01=1.02; //  Initial Pressure in bar
+beta1=61.4; // air angle at the inlet of axial inducer blades
+gamma=1.4;
+N=7200; // rotor Speed in RPM
+d1=0.175; // Mean Blade ring diameter at entry
+d2=0.5; // impeller diameter at exit
+cp=1005; // Specific Heat at Constant Pressure in J/(kgK)
+A1=0.0412; // Area of cross section at the impeller inlet
+R=287;
+b2=A1/(%pi*d2);
+disp("cm",b2*1e2,"(a)width of the impeller at exit is")
+u2=%pi*d2*N/60; 
+//for N=7200 rpm
+p1=0.9444579; // from Ex18.27  
+pr=1.4206988; //pressure ratio 
+m=5.0061078; //mass flow rate of air in kg/s   
+T02=370.35381;
+ro2=1.1; //trial and error
+cr2(1)=m/(A1*ro2);
+n=2;
+for i=1:n
+    c2(i)=sqrt(cr2(i)^2+(u2^2));
+    T2=T02-((c2(i)^2)/(2*cp));
+    p02=pr*p01;
+    p2=p02*((T2/T02)^(1/((gamma-1)/gamma)));
+ro2=(p2*1e5)/(R*T2);
+cr2(i+1)=m/(ro2*A1);
+end
+cr=cr2(3);
+disp(p2/p1,"(b)the static pressure ratio is")
+
+//part(c)
+alpha2=atand(cr/u2);
+disp("degree",alpha2,"(c)the direction alpha2 of the absolute velocity vector(c2) or the diffuser angle at entry is")
diff --git a/2223/CH18/EX18.29/Ex18_29.sav b/2223/CH18/EX18.29/Ex18_29.sav
new file mode 100755
index 000000000..db5042d3a
--- /dev/null
+++ b/2223/CH18/EX18.29/Ex18_29.sav
diff --git a/2223/CH18/EX18.29/Ex18_29.sce b/2223/CH18/EX18.29/Ex18_29.sce
new file mode 100755
index 000000000..89f23a68d
--- /dev/null
+++ b/2223/CH18/EX18.29/Ex18_29.sce
@@ -0,0 +1,61 @@
+// scilab Code Exa 18.29 Centrifugal compressor with vaned diffuser 
+T01=310;  // in Kelvin
+p01=1.103; //  Initial Pressure in bar
+dh=0.10; // hub diameter in m
+d2=0.55; // impeller diameter in m
+c1=100; // Velocity of air at the entry of inducer
+c3=c1; // Velocity of air at diffuser exit
+shi=1.035; // power input factor
+mu=0.9; // slip factor
+m=7.5; //  in kg/s
+gamma=1.4;
+N=15e3; // rotor Speed in RPM
+disp("(a)for radially tipped blades")
+cp=1005; // Specific Heat at Constant Pressure in J/(kgK)
+R=287;
+n_tt=0.81; // total to total efficiency
+T1=T01-((c1^2)/(2*cp));
+p1=p01*((T1/T01)^(gamma/(gamma-1)));
+ro1=(p1*1e5)/(R*T1);
+A1=m/(ro1*c1);
+dt=sqrt((A1*4/(%pi))+(dh^2));
+disp("cm",dt*1e2,"(i)tip diameter of the inducer at entry is")
+d1=0.5*(dt+dh); // Mean Blade ring diameter
+u1=%pi*d1*N/60;
+w1=sqrt((u1^2)+(c1^2));
+a1=sqrt(gamma*R*T1);
+M1_rel=w1/a1;
+disp(M1_rel,"(ii)the Relative Mach number at inducer blade entry Mw1=")
+u2=%pi*d2*N/60;
+w_st=shi*mu*(u2^2);
+T02=T01+(w_st/cp);
+T02s=T01+(n_tt*(T02-T01));
+pr_0=(T02s/T01)^(gamma/(gamma-1));
+disp(pr_0,"(iii)stagnation pressure ratio developed is")
+P=m*cp*(T02-T01);
+disp("kW",P*1e-3,"(iv)the power required is")
+disp("(b)for vaned diffuser")
+c_theta2=mu*u2; // velocity of whirl(swirl component) at the impeller exit
+// vaneless space between the impeller exit and the vaned diffuser entry=0.1*impeller radius
+//r2s=r2*1.1;
+// width of the casing after the impeller exit=1.4*impeller passage width
+c_theta2s=c_theta2/(1.1*1.4);
+cr2=c1;
+cr2s=cr2/(1.1*1.4);
+c2s=sqrt((cr2s^2)+(c_theta2s^2));
+alpha2s=atand(cr2s/c_theta2s);
+disp("degree",alpha2s,"(i)the direction of flow at the diffuser entry is alpha2s=")
+T2s=T02-((c2s^2)/(2*cp));
+a2s=sqrt(gamma*R*T2s);
+M2s=c2s/a2s;
+disp(M2s,"(ii)the Mach number at the diffuser entry is")
+Ar=c2s/c3;
+d3_2s=1.16; // d3/d2s from last trial given in the book
+alpha3=acosd(cosd(alpha2s)/d3_2s);
+Ar_v=d3_2s*sind(alpha3)/(sind(alpha2s));
+disp(Ar_v,"(iii)Area ratio of the vaned diffuser is")
+T03=T02;
+T3=T03-((c3^2)/(2*cp));
+pr3_1=(((T3*T01)/(T1*T03))^(gamma/(gamma-1)))*pr_0;
+disp(pr3_1,"(iv)the static pressure ratio of the compressor is")
+disp("comment: Calculations in the book are wrong in the beginning itself for p1. so the values slightly differs here only for part(a)")
diff --git a/2223/CH18/EX18.3/Ex18_3.sav b/2223/CH18/EX18.3/Ex18_3.sav
new file mode 100755
index 000000000..cbd6af513
--- /dev/null
+++ b/2223/CH18/EX18.3/Ex18_3.sav
diff --git a/2223/CH18/EX18.3/Ex18_3.sce b/2223/CH18/EX18.3/Ex18_3.sce
new file mode 100755
index 000000000..115222ee2
--- /dev/null
+++ b/2223/CH18/EX18.3/Ex18_3.sce
@@ -0,0 +1,7 @@
+// scilab Code Exa 18.3 Irreversible flow in nozzles
+pr=0.843; // pr=p/p0
+n_n=0.95; // nozzle efficiency
+gamma=1.4;
+Ms=0.5; // from gas tables for gammma and pr value
+Ma=sqrt((2/(gamma-1))*(n_n/(1-n_n+(2/((gamma-1)*(Ms^2))))));
+disp(Ma,"actual value of the Mach number is")
diff --git a/2223/CH18/EX18.30/Ex18_30.sav b/2223/CH18/EX18.30/Ex18_30.sav
new file mode 100755
index 000000000..7c346f35a
--- /dev/null
+++ b/2223/CH18/EX18.30/Ex18_30.sav
diff --git a/2223/CH18/EX18.30/Ex18_30.sce b/2223/CH18/EX18.30/Ex18_30.sce
new file mode 100755
index 000000000..ead21177c
--- /dev/null
+++ b/2223/CH18/EX18.30/Ex18_30.sce
@@ -0,0 +1,36 @@
+// scilab Code Exa 18.30 Inward Flow Radial Gas turbine
+
+T1=873; // the gas entry temperature at nozzle in Kelvin
+p1=4; // the gas entry pressure at nozzle in bar
+n_T=0.85; // isentropic efficiency
+d2=0.4; // rotor blade ring diameter at entry in m
+d3=0.2; // rotor blade ring diameter at exit in m
+pr_t=4; // static Pressure Ratio across the turbine(p3/p1)
+pr_n=2; // static Pressure Ratio across the nozzles(p3/p1) 
+phi=0.3; // flow coefficient at impeller entry
+gamma=1.4;
+N=18e3; // rotor Speed in RPM
+m=5; // mass flow rate of gas in kg/s
+cp=1005; // Specific Heat at Constant Pressure in J/(kgK)
+R=287;
+u2=%pi*d2*N/60;
+u3=%pi*d3*N/60;
+cr2=phi*u2;
+// part(a)
+T3ss=T1/(pr_t^((gamma-1)/gamma));
+T3=T1-n_T*(T1-T3ss);
+T2s=T1/(pr_n^((gamma-1)/gamma));
+T2=T2s+(0.5*(T3-T3ss)); // half of the losses(T3-T3ss) occur in the nozzles
+p2=p1/pr_n;
+rho2=(p2*1e5)/(R*T2);
+b2=m/(rho2*cr2*%pi*d2);
+disp("cm",b2*1e2,"(a)axial width of the impeller blade passage at entry is")
+alpha2=atand(cr2/u2);
+disp("degree",alpha2,"(b)nozzle exit air angle is")
+cx3=cr2;
+beta3=atand(cx3/u3);
+disp("degree",beta3,"(c)impeller exit air angle is")
+c_theta3=0;
+c_theta2=u2;
+P=m*(u2*c_theta2-u3*c_theta3);
+disp("kW",P*1e-3,"(d)power developed is")
diff --git a/2223/CH18/EX18.31/Ex18_31.sav b/2223/CH18/EX18.31/Ex18_31.sav
new file mode 100755
index 000000000..8f5140403
--- /dev/null
+++ b/2223/CH18/EX18.31/Ex18_31.sav
diff --git a/2223/CH18/EX18.31/Ex18_31.sce b/2223/CH18/EX18.31/Ex18_31.sce
new file mode 100755
index 000000000..17d3b3c6c
--- /dev/null
+++ b/2223/CH18/EX18.31/Ex18_31.sce
@@ -0,0 +1,57 @@
+// scilab Code Exa 18.31 Cantilever Type IFR turbine
+
+P=150; // Power developed in kW
+T01=960; // the gas entry temperature at nozzle in Kelvin
+p01=3; // the gas entry pressure at nozzle in bar
+beta2=45; // air angle at rotor blade entry (from radial direction)
+beta3=65; // air angle at rotor blade exit (from radial direction)
+d2=0.2; // rotor blade ring diameter at entry in m
+d3=0.15; // rotor blade ring diameter at exit in m
+gamma=1.4;
+N=36e3; // rotor Speed in RPM
+alpha_2=15;  //  air angle at nozzle exit(from tangential direction)
+pr0=2.29; // total-to-static Pressure Ratio(p01/p3) 
+n_N=0.94; // Nozzle Efficiency 
+cp=1100; // Specific Heat at Constant Pressure in J/(kgK)
+R=cp*((gamma-1)/gamma);
+u2=%pi*d2*N/60;
+u3=%pi*d3*N/60;
+
+// part(a) mass flow rate of the gas
+cr2_theta2=tand(alpha_2); // cr2_theta2=cr2/c_theta2
+c_theta2=u2/(1-cr2_theta2); // c_theta2=cr2*tan(alpha2)+u2
+cr2=c_theta2*cr2_theta2;
+cr3=cr2;
+c_theta3=(cr3*tand(beta3))-u3;
+w_st=(u2*c_theta2)+(u3*c_theta3);
+m=P/(w_st*1e-3);
+disp("kg/s",m,"(a)mass flow rate of the gas is")
+
+// part(b)rotor blade axial length at entry
+c2=cr2/sind(alpha_2);
+T2s=T01-((0.5*(c2^2))/(cp*n_N));
+T2=T01-((T01-T2s)*n_N);
+p_rn=(T2s/T01)^(gamma/(gamma-1));
+p2=p01*p_rn;
+rho2=(p2*1e5)/(R*T2);
+b2=m/(rho2*cr2*%pi*d2);
+disp("cm",b2*1e2,"(b)rotor blade axial length at entry is")
+
+// part(c)total-to-total turbine efficiency
+T03ss=T01*(pr0^((1-gamma)/gamma));
+n_T=P/(m*cp*1e-3*(T01-T03ss));
+disp("%",n_T*1e2,"(c)total-to-total turbine efficiency is")
+
+//part(d)rotor blade length at exit
+p03=p01/pr0;
+T03=T01-(P/(m*cp*1e-3));
+c3=sqrt((cr3^2)+(c_theta3^2));
+T3=T03-((cr3^2)/(2*cp));
+p3=p03*((T3/T03)^(gamma/(gamma-1)));
+ro3=(p3*1e5)/(R*T3);
+b3=m/(ro3*cr3*%pi*d3);
+disp("cm",b3*1e2,"(d)rotor blade length at exit is")
+
+// part(e) degree of reaction
+DOR=(T2-T3)/(T01-T03);
+disp("%",DOR*1e2,"(e)degree of reaction is")
diff --git a/2223/CH18/EX18.32/Ex18_32.sav b/2223/CH18/EX18.32/Ex18_32.sav
new file mode 100755
index 000000000..782f52ecf
--- /dev/null
+++ b/2223/CH18/EX18.32/Ex18_32.sav
diff --git a/2223/CH18/EX18.32/Ex18_32.sce b/2223/CH18/EX18.32/Ex18_32.sce
new file mode 100755
index 000000000..30d6cfbdf
--- /dev/null
+++ b/2223/CH18/EX18.32/Ex18_32.sce
@@ -0,0 +1,9 @@
+// scilab Code Exa 18.32 IFR turbine stage efficiency
+
+// part(b)
+R=0.48;
+sigma_s=0.6;
+n_n=0.92;
+alpha_2=15;  //  air angle at nozzle exit(from tangential direction)
+n_st=2*sigma_s*sqrt(n_n*(1-R))*cosd(alpha_2);
+disp("%",n_st*100,"stage efficiency of the radial turbine is")
diff --git a/2223/CH18/EX18.33/Ex18_33.sav b/2223/CH18/EX18.33/Ex18_33.sav
new file mode 100755
index 000000000..fd6d6ad6f
--- /dev/null
+++ b/2223/CH18/EX18.33/Ex18_33.sav
diff --git a/2223/CH18/EX18.33/Ex18_33.sce b/2223/CH18/EX18.33/Ex18_33.sce
new file mode 100755
index 000000000..37419ad21
--- /dev/null
+++ b/2223/CH18/EX18.33/Ex18_33.sce
@@ -0,0 +1,35 @@
+// scilab Code Exa 18.33 Vertical Axis Crossflow Wind turbine
+
+c1=24/3.6; // wind speed in m/s
+c2=30/3.6; // rotor speed in m/s
+m1=25; // mass flow rate of air at wind side in kg/s
+m2=31.25; // rotor  air mass flow rate in kg/s
+d1=3; // rotor outer diameter in m
+d2=2; // rotor inner diameter in m
+gamma=1.4;
+alpha=37;  //  air angle at rotor entry(from tangential direction)
+c(1)=c1;
+c(2)=c2;
+m(1)=m1;
+m(2)=m2;
+
+for i=1:2
+c_theta1=c(i)*cosd(alpha);
+u1=c_theta1/2;
+u2=u1*d2/d1;
+disp("kmph",c(i)*3.6,"for speed=")
+
+// part(a)optimum rotor speed
+N=60*u1/(%pi*d1);
+disp("rpm",N,"(a)optimum rotor speed is")
+
+// part(b)blade to wind speed ratio
+sigma=u1/c(i);
+disp(sigma,"blade to wind speed ratio is")
+
+// part(c)hydraulic powers and efficiencies
+Ph=m(i)*((2*(u1^2))+(u2^2));
+disp("Watts",Ph,"(c)hydraulic power is")
+n_h=((2*(u1^2))+(u2^2))/(0.5*(c(i)^2));
+disp("%",n_h*1e2,"and hydraulic efficiency is")
+end
diff --git a/2223/CH18/EX18.34/Ex18_34.sav b/2223/CH18/EX18.34/Ex18_34.sav
new file mode 100755
index 000000000..7315d0f27
--- /dev/null
+++ b/2223/CH18/EX18.34/Ex18_34.sav
diff --git a/2223/CH18/EX18.34/Ex18_34.sce b/2223/CH18/EX18.34/Ex18_34.sce
new file mode 100755
index 000000000..6672f1185
--- /dev/null
+++ b/2223/CH18/EX18.34/Ex18_34.sce
@@ -0,0 +1,16 @@
+// scilab Code Exa 18.34 Counter Rotating fan
+
+n=0.809; // combined efficiency of the fans
+phi=0.245; // flow coefficient
+A=0.212; // data from Ex14.1
+d=0.45; // data from Ex14.1
+u=22.62; // data from Ex14.1
+cx=phi*u;
+Q=1.175; // in m3/s
+delp0_I=550.755; // data from Ex14.1
+delp0_II=delp0_I;
+delp0=delp0_I+delp0_II;
+disp("mm W.G.",delp0/9.81,"(a)the overall pressure rise obtained is")
+IP=Q*delp0; // power required for isentropic flow in Watts
+P=IP/n;
+disp("kW",P*1e-3,"(b)the Power required is")
diff --git a/2223/CH18/EX18.35/Ex18_35.sav b/2223/CH18/EX18.35/Ex18_35.sav
new file mode 100755
index 000000000..896094380
--- /dev/null
+++ b/2223/CH18/EX18.35/Ex18_35.sav
diff --git a/2223/CH18/EX18.35/Ex18_35.sce b/2223/CH18/EX18.35/Ex18_35.sce
new file mode 100755
index 000000000..b19955a2f
--- /dev/null
+++ b/2223/CH18/EX18.35/Ex18_35.sce
@@ -0,0 +1,26 @@
+// scilab Code Exa 18.35 Sirocco Radial fan 1440 rpm
+
+d2=0.4; // outer diameter of the impeller in m
+d1=0.36; // inner diameter of the impeller in m
+b=0.5; // axial length of the impeller in m
+rho=1.25; // density of air in kg/m3
+N=1440; // rotor Speed in RPM
+P=50; // Power required in kW
+
+u1=%pi*d1*N/60;
+u2=%pi*d2*N/60;
+ 
+beta1=atand(d2/d1);
+disp("degree",beta1,"(a)the blade air angle at the impeller entry beta1=")
+beta2=90-beta1;
+disp("degree",beta2,"and the blade air angle at the impeller exit beta2=")
+delp0=2*rho*(u2^2);
+disp("mm W.G.",delp0/9.81,"(b)the stagnation pressure rise across the fan is") 
+cr1=u1*tand(beta1);
+m=rho*cr1*%pi*d1*b;
+disp("kg/s",m,"(c)mass flow rate of the air through the fan is")
+c_theta1=0; // for zero inlet swirl
+w_st=2*(u2^2);
+IP=m*w_st/1000; // ideal power required to drive the fan in kW
+n=IP/P;
+disp("%",n*1e2,"(d)the Efficiency of the fan is") 
diff --git a/2223/CH18/EX18.37/Ex18_37.sav b/2223/CH18/EX18.37/Ex18_37.sav
new file mode 100755
index 000000000..289e95f40
--- /dev/null
+++ b/2223/CH18/EX18.37/Ex18_37.sav
diff --git a/2223/CH18/EX18.37/Ex18_37.sce b/2223/CH18/EX18.37/Ex18_37.sce
new file mode 100755
index 000000000..2a1b25908
--- /dev/null
+++ b/2223/CH18/EX18.37/Ex18_37.sce
@@ -0,0 +1,52 @@
+// scilab Code Exa 18.37 Calculation for the specific speed
+
+//part(1)specific speed of Axial flow gas turbine
+P1=0.5e3; // Gas Turbine Power Output in kW
+N1=60; // Speed in RPS
+omega1=%pi*2*N1;
+ro1=2;
+delh_1=30; // change of enthalpy in kJ
+NS_1=omega1*sqrt(P1*10e2/ro1)*((delh_1*1e3)^(-5/4));
+disp(NS_1,"1.the specific speed of Axial flow gas turbine is")
+
+//part(2)specific speed of IFR gas turbine
+P2=0.75e3; // Gas Turbine Power Output in kW
+N2=300; // Speed in RPS
+omega2=%pi*2*N2;
+ro2=1;
+delh_2=250; // change of enthalpy in kJ
+NS_2=omega2*sqrt(P2*10e2/ro2)*((delh_2*1e3)^(-5/4));
+disp(NS_2,"2.the specific speed of IFR gas turbine is") 
+
+// part(3)the specific speed of an axial compressor
+N_c=120; // Speed in RPS
+omega_c=%pi*2*N_c;
+Q_c=25; // flow rate in m3/s
+delh_3=40; // change of enthalpy in kJ
+NS_c=omega_c*sqrt(Q_c)*((delh_3*1e3)^(-3/4));
+disp(NS_c,"3.the specific speed of an axial compressor is")
+
+// part(4)the specific speed of a centrifugal compressor
+Q=5; // flow rate in m3/s
+delh_4=35; // change of enthalpy in kJ
+NS_4=omega_c*sqrt(Q)*((delh_4*1e3)^(-3/4));
+disp(NS_4,"4.the specific speed of a centrifugal compressor is")
+
+// part(5)the specific speed of an axial fan
+N5=22; // Speed in RPS
+omega_5=2*%pi*N5;
+Q_5=3.5; // flow rate in m3/s
+rho=1.25; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+H1=55/rho; // head in m
+NS_5=omega_5*sqrt(Q_5)*((g*H1)^(-3/4));
+disp(NS_5,"5.the dimensionless specific speed of an axial fan is")
+
+// part(6)the specific speed of a Radial fan
+N6=20; // Speed in RPS
+omega_6=2*%pi*N6;
+Q_6=1.4; // flow rate in m3/s
+
+H2=52/rho; // head in m
+NS_6=omega_6*sqrt(Q_6)*((g*H2)^(-3/4));
+disp(NS_6,"6.the dimensionless specific speed of a Radial fan is")
diff --git a/2223/CH18/EX18.38/Ex18_38.sav b/2223/CH18/EX18.38/Ex18_38.sav
new file mode 100755
index 000000000..9997f8ac9
--- /dev/null
+++ b/2223/CH18/EX18.38/Ex18_38.sav
diff --git a/2223/CH18/EX18.38/Ex18_38.sce b/2223/CH18/EX18.38/Ex18_38.sce
new file mode 100755
index 000000000..dc4a3785f
--- /dev/null
+++ b/2223/CH18/EX18.38/Ex18_38.sce
@@ -0,0 +1,28 @@
+// scilab Code Exa 18.38 Kaplan turbine 70 rpm
+
+//part(a)flow rate and specific speed 
+P=8e3; // Gas Power Output in kW
+N=70; // Speed in RPM
+H=10; // net head in m
+n_m=0.85; // efficiency
+omega=%pi*2*N/60;
+NS=omega*sqrt(P*10e2)*(H^(-5/4))/549.016;
+disp(NS,"(a)the specific speed of turbine is")
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+Q=P*1e3/(n_m*rho*g*H);
+disp("m3/s",Q,"and the flow rate is")
+
+// part(b) determining the speed, flow rate and power for the model
+Dp_m=12; // Dp_m=Dp/Dm
+Np=N; // Speed for prototype
+Hm=3; // head of the model
+Hp=H; // head for prototype
+Nm=Np*Dp_m*sqrt(Hm/Hp);
+disp("rpm",Nm,"(b)speed for the model is")
+Dm_p=1/Dp_m;
+Qp=Q;
+Qm=(Dm_p^2)*sqrt(Hm/Hp)*Qp;
+disp("m3/s",Qm,"the flow rate for model is")
+Pm=n_m*rho*g*Qm*Hm;
+disp("kW",Pm*1e-3,"the power for the model is")
diff --git a/2223/CH18/EX18.39/Ex18_39.sav b/2223/CH18/EX18.39/Ex18_39.sav
new file mode 100755
index 000000000..4b7b7c075
--- /dev/null
+++ b/2223/CH18/EX18.39/Ex18_39.sav
diff --git a/2223/CH18/EX18.39/Ex18_39.sce b/2223/CH18/EX18.39/Ex18_39.sce
new file mode 100755
index 000000000..d34382130
--- /dev/null
+++ b/2223/CH18/EX18.39/Ex18_39.sce
@@ -0,0 +1,22 @@
+// scilab Code Exa 18.39 Calculation for the Pelton Wheel
+
+Nm=102; // Speed for the model in RPM
+Hm=30; // net head for the model in m
+n_m=1; // Assuming efficiency
+Qm=0.345; // discharge in m3/s
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+omega_m=%pi*2*Nm/60;
+Pm=n_m*rho*g*Qm*Hm;
+NS=omega_m*sqrt(Pm)*(Hm^(-5/4))/549.016;
+disp(NS,"the specific speed of turbine is")
+
+// determining the speed, flow rate and power for the prototype
+Hp=1500; // head for prototype
+Pp=((Hp/Hm)^(3/2))*Pm;
+disp("MW",Pp*1e-6,"the power for the prototype is")
+omega_p=NS*549.016*(Hp^(5/4))/(sqrt(Pp));
+Np=omega_p*60/(2*%pi);
+disp("rpm",Np,"speed for the prototype is")
+Qp=sqrt(Hp/Hm)*Qm;
+disp("m3/s",Qp,"the flow rate for prototype is")
diff --git a/2223/CH18/EX18.4/Ex18_4.sav b/2223/CH18/EX18.4/Ex18_4.sav
new file mode 100755
index 000000000..e69b02c51
--- /dev/null
+++ b/2223/CH18/EX18.4/Ex18_4.sav
diff --git a/2223/CH18/EX18.4/Ex18_4.sce b/2223/CH18/EX18.4/Ex18_4.sce
new file mode 100755
index 000000000..8e55e700d
--- /dev/null
+++ b/2223/CH18/EX18.4/Ex18_4.sce
@@ -0,0 +1,29 @@
+// scilab Code Exa 18.4 Calculation on a Diffuser 
+
+pe=35; // Initial Pressure in mm W.G.
+pa=1.0135; // ambient pressure in bar
+c1=100; // entry velocity in m/s
+C_pa=0.602; // actual pressure recovery coefficient
+ro=1.25; // density in kg/m3
+g=9.81; // Gravitational acceleration in m/s^2
+Ar=1.85; // Area Ratio of Diffuser
+
+// part(a)
+C_ps=1-(1/(Ar^2));
+disp(C_ps,"(a)ideal value of the pressure recovery coefficient is")
+
+// part(b)
+n_D=C_pa/C_ps;
+disp ("%",n_D*1e2,"(b)Efficiency of the diffuser is")
+
+// part(c)
+p1=pa+(pe*g*1e-5);
+p01=p1+(0.5*ro*(c1^2)*1e-5);
+delp_0=(C_ps-C_pa)*(0.5*ro*(c1^2)*1e-5);
+disp("mm W.G.",delp_0*1e5/g,"(c)the stagnation pressure loss across the diffuser is")
+
+// part(d)
+p02=p01-delp_0;
+c2=c1/Ar;
+p2=p02-(0.5*ro*(c2^2)*1e-5);
+disp("mm W.G.",(p2-pa)*1e5/g,"(d)the gauge pressure at the diffuser exit is")
diff --git a/2223/CH18/EX18.40/Ex18_40.sav b/2223/CH18/EX18.40/Ex18_40.sav
new file mode 100755
index 000000000..3b98354f1
--- /dev/null
+++ b/2223/CH18/EX18.40/Ex18_40.sav
diff --git a/2223/CH18/EX18.40/Ex18_40.sce b/2223/CH18/EX18.40/Ex18_40.sce
new file mode 100755
index 000000000..bf1ff16a8
--- /dev/null
+++ b/2223/CH18/EX18.40/Ex18_40.sce
@@ -0,0 +1,27 @@
+// scilab Code Exa 18.40 Calculation for the Francis turbine
+
+// part(a) determining the speed, specific speed and power for the model
+Qm=0.148; // discharge in m3/s
+N=910; // Speed in RPM
+Hm=25; // net head in m
+n=0.9; // efficiency
+omega=%pi*2*N/60;
+NS=omega*sqrt(Qm)*(Hm^(-3/4))*0.1804;
+disp(NS,"(a)the specific speed of turbine is")
+Nu=N/(sqrt(Hm));
+disp("rpm",Nu,"unit speed for the model is")
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+Pm=rho*g*Qm*Hm;
+disp("kW",Pm*1e-3,"the power for the model is")
+
+// part(b)determining the speed, flow rate and power for the prototype
+Hp=250; // head for prototype
+Dp_m=6; // Dp_m=Dp/Dm
+Qp=sqrt(Hp/Hm)*Qm*(Dp_m^2);
+disp("m3/s",Qp,"(b)the flow rate for prototype is")
+Pp=rho*g*Qp*Hp*n;
+disp("MW",Pp*1e-6,"the power for the prototype is")
+omega_p=NS*(Hp^(3/4))/(0.1804*sqrt(Qp));
+Np=omega_p*60/(2*%pi);
+disp("rpm",Np,"speed for the prototype is")
diff --git a/2223/CH18/EX18.41/Ex18_41.sav b/2223/CH18/EX18.41/Ex18_41.sav
new file mode 100755
index 000000000..d2bd3875e
--- /dev/null
+++ b/2223/CH18/EX18.41/Ex18_41.sav
diff --git a/2223/CH18/EX18.41/Ex18_41.sce b/2223/CH18/EX18.41/Ex18_41.sce
new file mode 100755
index 000000000..adbe3a3c5
--- /dev/null
+++ b/2223/CH18/EX18.41/Ex18_41.sce
@@ -0,0 +1,19 @@
+// scilab Code Exa 18.41 Calculation for the Pelton Wheel
+NS=0.1; //specific speed
+H1=1000; // net head for the model in m
+Q1=1; // discharge in m3/s
+omega1=NS*(H1^(3/4))/(sqrt(Q1)*0.1804);
+N1=omega1*60/(2*%pi);
+disp("rpm",N1,"speed of the rotation is")
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+P1=rho*g*Q1*H1;
+
+// determining the speed, flow rate and power for the prototype
+H2=100; // head for prototype
+N2=N1*sqrt(H2/H1);
+disp("rpm",N2,"speed for the prototype is")
+Q2=sqrt(H2/H1)*Q1;
+disp("m3/s",Q2,"the discharge for the prototype is")
+P2=((H2/H1)^(3/2))*P1;
+disp("MW",P2*1e-6,"the power for the prototype is")
diff --git a/2223/CH18/EX18.42/Ex18_42.sav b/2223/CH18/EX18.42/Ex18_42.sav
new file mode 100755
index 000000000..6a9c549e8
--- /dev/null
+++ b/2223/CH18/EX18.42/Ex18_42.sav
diff --git a/2223/CH18/EX18.42/Ex18_42.sce b/2223/CH18/EX18.42/Ex18_42.sce
new file mode 100755
index 000000000..5d8442489
--- /dev/null
+++ b/2223/CH18/EX18.42/Ex18_42.sce
@@ -0,0 +1,23 @@
+// scilab Code Exa 18.42 Calculation for Tidal Power Plant
+
+T=50e6; // capacity of basin in cubic meters of sea water
+N=60; // Speed for the model in RPM
+NS=3; //specific speed
+H=9.8; // net head for the model in m
+n_o=0.78; // Assuming efficiency
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+n(1)=5; // number of turbines
+n(2)=10;
+omega=%pi*2*N/60;
+
+P=(NS^2)*(H^(5/2))*(549.016^2)/(omega^2);
+disp("MW",P*1e-6,"(a)the power for the turbines is")
+Q=P/(n_o*rho*g*H);  // discharge in m3/s
+disp("m3/s",Q,"(b)the discharge rate for the turbines is")
+disp("(c)")
+for i=1:2
+    disp(n(i),"when number of turbines are:")
+    t=T/(n(i)*Q*3600);
+disp("hours",t,"duration of operation is")
+end
diff --git a/2223/CH18/EX18.43/Ex18_43.sav b/2223/CH18/EX18.43/Ex18_43.sav
new file mode 100755
index 000000000..142b5db00
--- /dev/null
+++ b/2223/CH18/EX18.43/Ex18_43.sav
diff --git a/2223/CH18/EX18.43/Ex18_43.sce b/2223/CH18/EX18.43/Ex18_43.sce
new file mode 100755
index 000000000..6d1a279dc
--- /dev/null
+++ b/2223/CH18/EX18.43/Ex18_43.sce
@@ -0,0 +1,37 @@
+// scilab Code Exa 18.43 Francis turbine 250 rpm
+
+NS=0.4; //specific speed
+N=250; // Speed in RPM
+H=75; // net head in m
+beta3=25; // exit angle of the runner blades
+n_o=0.81; // overall efficiency
+g=9.81; // gravitational acceleration in m/s2
+rho=1000; // density in kg/m3
+// part(a)
+u2=0.6*sqrt(2*g*H);
+cr2=0.21*sqrt(2*g*H);
+omega=%pi*2*N/60;
+Q=(NS^2)*(H^(3/2))/((0.1804^2)*(omega^2));
+disp("m3/s",Q,"(a)the discharge rate for the turbine is")
+// part(b)
+d2=u2*60/(%pi*N);
+disp("m",d2,"(b)outer diameter of the runner blade ring is")
+cr3=cr2;
+cx3=cr3;
+//Euler work,w_ET=u2*c_theta2
+c_theta2=((g*H)-(0.5*(cx3^2)))/u2;
+u3=cx3/(tand(beta3));
+d3=u3*60/(%pi*N);
+disp("m",d3,"and inner diameter of the runner blade ring is")
+// part(c)
+alpha2=atand(cr2/c_theta2);
+disp("degree",alpha2,"(c)the inlet guide vane exit angle is")
+beta2=atand(cr2/(c_theta2-u2));
+disp("degree",beta2,"and inlet angle of the runner blades is beta2= ")
+// part(d)
+n_h=(u2*c_theta2)/(g*H);
+disp("%",n_h*1e2,"(d)the hydraulic efficiency is")
+// part(e)
+P=n_o*rho*g*Q*H;
+disp("MW",P*1e-6,"(e)the output power is")
+disp("comment: the calculation for c_theta2 is done wrongly in the book. hence the values of alpha2,beta2, n_h differs from the book.")
diff --git a/2223/CH18/EX18.44/Ex18_44.sav b/2223/CH18/EX18.44/Ex18_44.sav
new file mode 100755
index 000000000..9b645247a
--- /dev/null
+++ b/2223/CH18/EX18.44/Ex18_44.sav
diff --git a/2223/CH18/EX18.44/Ex18_44.sce b/2223/CH18/EX18.44/Ex18_44.sce
new file mode 100755
index 000000000..d04a95324
--- /dev/null
+++ b/2223/CH18/EX18.44/Ex18_44.sce
@@ -0,0 +1,43 @@
+// scilab Code Exa 18.44 Pelton Wheel 360 rpm
+
+d=2; // mean diameter in m
+N=360; // Speed in RPM
+theta=150; //deflection angle of water jet in degree
+H=140; // net head for the model in m
+q=45000; // discharge in litres/min
+Q=q*1e-3/60; // in m3/s
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+// part(a)
+u=%pi*d*N/60;
+c2=sqrt(2*g*H);
+sigma=u/c2;
+disp(sigma,"(a)blade to jet speed ratio is")
+// part(b)
+w2=c2-u;
+w3=w2;
+beta2=0;
+beta3=180-theta;
+cy2=c2;
+cy3=u-(w3*cosd(beta3));
+w_T=u*(cy2-cy3);
+m=rho*Q;
+P_T=m*w_T;
+disp("kW",P_T*1e-3,"(b)the power developed is")
+// part(c)
+n=w_T/(0.5*(c2^2));
+disp("%",n*1e2,"(c)the efficiency is")
+// part(d)
+n_max=0.5*(1+cosd(beta3));
+disp("%",n_max*1e2,"(d)the Maximum efficiency is")
+P_max=m*g*H*n_max;
+disp("kW",P_max*1e-3,"and the Maximum power developed is")
+// part(e)
+sigma_opt=0.5; // for Maximum efficiency
+u_opt=sigma_opt*c2;
+N_opt=u_opt*60/(d*%pi);
+disp("rpm",N_opt,"(e)speed of the rotation corresponding to Maximum efficiency is")
+// part(f)
+omega=%pi*2*N/60;
+NS=omega*sqrt(P_T)*(H^(-5/4))/549.016;
+disp(NS,"(f)the specific speed of turbine is")
diff --git a/2223/CH18/EX18.45/Ex18_45.sav b/2223/CH18/EX18.45/Ex18_45.sav
new file mode 100755
index 000000000..b1ddd766e
--- /dev/null
+++ b/2223/CH18/EX18.45/Ex18_45.sav
diff --git a/2223/CH18/EX18.45/Ex18_45.sce b/2223/CH18/EX18.45/Ex18_45.sce
new file mode 100755
index 000000000..972ae329d
--- /dev/null
+++ b/2223/CH18/EX18.45/Ex18_45.sce
@@ -0,0 +1,32 @@
+// scilab Code Exa 18.45 Kaplan turbine 120 rpm
+
+N=120; // Speed in RPM
+H=25; // net head in m
+Q=120; // discharge in m3/s
+dt=5; // runner diameter in m
+dh_t=0.4; // hub-tip ratio of the runner
+beta2=150; //inlet angle of the runner blades in degree
+n_o=0.8; // overall efficiency
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+// part(a)
+P=n_o*rho*g*Q*H;
+disp("MW",P*1e-6,"(a)the output power is")
+// part(b)
+omega=%pi*2*N/60;
+NS=omega*sqrt(P)*(H^(-5/4))/549.016;
+disp(NS,"(b)the specific speed of turbine is")
+// part(c)
+dh=dh_t*dt;
+d=0.5*(dt+dh); // mean diameter of the impeller blade in m
+u=%pi*d*N/60;
+cx=Q*4/(%pi*(dt^2-dh^2));
+cy2=u-(cx*tand(90-(180-beta2)));
+alpha2=atand(cx/cy2);
+disp("degree",alpha2,"(c)the inlet guide vane exit angle is")
+// part(d)
+beta3=atand(cx/u);
+disp("degree",beta3,"(d)the exit angle of the runner blades is beta3= ")
+// part(e)
+n_h=(u*cy2)/(g*H);
+disp("%",n_h*1e2,"(e)the hydraulic efficiency is")
diff --git a/2223/CH18/EX18.46/Ex18_46.sav b/2223/CH18/EX18.46/Ex18_46.sav
new file mode 100755
index 000000000..b60ee9f6a
--- /dev/null
+++ b/2223/CH18/EX18.46/Ex18_46.sav
diff --git a/2223/CH18/EX18.46/Ex18_46.sce b/2223/CH18/EX18.46/Ex18_46.sce
new file mode 100755
index 000000000..b23c1e020
--- /dev/null
+++ b/2223/CH18/EX18.46/Ex18_46.sce
@@ -0,0 +1,34 @@
+// scilab Code Exa 18.46 Fourneyron Turbine 360 rpm
+
+d2=3; // outer diameter of the impeller in m
+d1=1.5; // inner diameter of the impeller in m
+H=50; // net head in m
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+N=360; // rotor Speed in RPM
+n_o=0.785; // overall efficiency
+P=4; // Power Output in MW
+u1=%pi*d1*N/60;
+u2=%pi*d2*N/60;
+// part(a)
+Q=P*1e6/(n_o*rho*g*H);
+disp("m3/s",Q,"(a)the discharge is")
+c2=9; // velocity of water at exit in m/s
+// part(b)
+w_ET=(g*H)-(0.5*(c2^2));
+n_h=w_ET/(g*H);
+disp("%",n_h*1e2,"(b)the hydraulic efficiency is")
+// part(c)
+cr2=c2;
+b=Q/(cr2*%pi*d2); // axial length of the impeller in m
+disp("cm",b*1e2,"(c)the runner passage width is")
+// part(d)
+beta2=atand(cr2/u2);
+disp("degree",beta2,"(d) the blade air angle at the impeller exit beta2=")
+c_theta1=w_ET/u1;
+cr1=Q/(b*%pi*d1);
+beta1=atand(cr1/(u1-c_theta1));
+disp("degree",beta1,"and the blade air angle at the impeller entry beta1=")
+// part(e)
+alpha1=atand(cr1/c_theta1);
+disp("degree",alpha1,"(e)the guide vane exit angle is")
diff --git a/2223/CH18/EX18.47/Ex18_47.sav b/2223/CH18/EX18.47/Ex18_47.sav
new file mode 100755
index 000000000..5f5e27c3a
--- /dev/null
+++ b/2223/CH18/EX18.47/Ex18_47.sav
diff --git a/2223/CH18/EX18.47/Ex18_47.sce b/2223/CH18/EX18.47/Ex18_47.sce
new file mode 100755
index 000000000..853707b83
--- /dev/null
+++ b/2223/CH18/EX18.47/Ex18_47.sce
@@ -0,0 +1,38 @@
+// scilab Code Exa 18.47 Crossflow Radial Hydro turbine
+
+N=50; // Speed in RPM
+H=25; // net head in m
+Q=150; // discharge in m3/s
+P=20; // Power Output in MW
+d1=3.5; //  runner diameter in m
+dr=1.3; // diameter ratio of the runner
+rho=1000; // density in kg/m3
+g=9.81; // gravitational acceleration in m/s2
+u1=%pi*d1*N/60;
+u2=u1/dr;
+c_theta1=2*u1;
+c_theta2=u2;
+w_st1=(u1*c_theta1)-(u2*c_theta2);
+u3=u2;
+c_theta3=u2;
+c_theta4=0;
+w_st2=(u3*c_theta3)-(u1*c_theta4);
+w_st=w_st1+w_st2;
+// part(a)
+n_h=w_st/(g*H);
+disp("%",n_h*1e2,"(a)the hydraulic efficiency is")
+Ph=rho*Q*w_st;
+disp("MW",Ph*1e-6,"and the hydraulic power is")
+n_o=P*1e6/(rho*Q*g*H);
+disp("%",n_o*1e2,"and the overall efficiency is")
+// part(b)
+omega=%pi*2*N/60;
+NS=omega*sqrt(P*1e6)*(H^(-5/4))/549.016;
+disp(NS,"(b)the specific speed of turbine is")
+// part(c)
+disp("(c)Adopting the flow model of the crossflow wind turbine")
+P_h=rho*Q*((2*(u1^2))+(u2^2));
+disp("MW",P_h*1e-6,"the hydraulic power is")
+nh=((2*(u1^2))+(u2^2))/(g*H);
+disp("%",nh*1e2,"and hydraulic efficiency is")
+
diff --git a/2223/CH18/EX18.48/Ex18_48.sav b/2223/CH18/EX18.48/Ex18_48.sav
new file mode 100755
index 000000000..e26068996
--- /dev/null
+++ b/2223/CH18/EX18.48/Ex18_48.sav
diff --git a/2223/CH18/EX18.48/Ex18_48.sce b/2223/CH18/EX18.48/Ex18_48.sce
new file mode 100755
index 000000000..c92769738
--- /dev/null
+++ b/2223/CH18/EX18.48/Ex18_48.sce
@@ -0,0 +1,13 @@
+// scilab Code Exa 18.48 Calculation on a Draft Tube 
+
+pa=1.013; // atmospheric pressure in bar
+p3=0.4*pa; // turbine exit pressure in bar
+rho=1e3; // density in kg/m3
+g=9.81; // Gravitational acceleration in m/s^2
+n_D=0.82; // Efficiency of the Draft Tube
+delHi=3.1058869; // from Ex 18.5
+// part(b)
+Hd=delHi;
+Hs=((pa-p3)*1e5/(rho*g))-(n_D*Hd); // Hs=Z3-Z4
+disp("m",Hs,"(b)the suction head(height of the turbine exit above the tail race) is")
+disp("comment: the calculation for Hs is done wrongly in the book. hence the value of Hs differs from the book.")
diff --git a/2223/CH18/EX18.49/Ex18_49.sav b/2223/CH18/EX18.49/Ex18_49.sav
new file mode 100755
index 000000000..252377f3e
--- /dev/null
+++ b/2223/CH18/EX18.49/Ex18_49.sav
diff --git a/2223/CH18/EX18.49/Ex18_49.sce b/2223/CH18/EX18.49/Ex18_49.sce
new file mode 100755
index 000000000..002551e2f
--- /dev/null
+++ b/2223/CH18/EX18.49/Ex18_49.sce
@@ -0,0 +1,34 @@
+// scilab Code Exa 18.49 Centrifugal pump 890 kW
+
+H=50; // head developed in m
+P=890; // Power required in kW
+NS=0.75; //specific speed
+rho=1e3;
+g=9.81; // Gravitational acceleration in m/s^2
+n_h=0.91; // hydraulic efficiency
+f=0.925; // blockage factor for the flow
+Q=1.5; // discharge in m3/s of water
+u2=0.8*sqrt(2*g*H);
+cr2=0.3*sqrt(2*g*H);
+dr=0.5; // diameter ratio(d1/d2)
+// part(a)
+omega=NS*(H^(3/4))/(0.1804*sqrt(Q));
+N=omega*60/(2*%pi);
+disp("rpm",N,"(a)the speed of rotation is")
+// part(b) impeller diameter
+d2=u2*60/(%pi*N);
+disp("m",d2,"(b)the impeller diameter is")
+//part(c)
+c_theta2=g*H/(u2*n_h);
+beta2=atand(cr2/(u2-c_theta2));
+disp("degree",beta2,"(c)the blade air angle at the impeller exit beta2=")
+u1=u2*dr;
+cr1=cr2;
+beta1=atand(cr1/u1);
+disp("degree",beta1,"and the blade air angle at the impeller entry beta1=")
+//part(d)
+b2=Q/(cr2*%pi*d2*f);
+disp("m",b2,"(d)the impeller width at exit is")
+//part(e)overall Efficiency
+n_o=rho*Q*H*g/(P*1e3);
+disp("%",n_o*1e2,"(e)overall efficiency is")
diff --git a/2223/CH18/EX18.5/Ex18_5.sav b/2223/CH18/EX18.5/Ex18_5.sav
new file mode 100755
index 000000000..b7a81337b
--- /dev/null
+++ b/2223/CH18/EX18.5/Ex18_5.sav
diff --git a/2223/CH18/EX18.5/Ex18_5.sce b/2223/CH18/EX18.5/Ex18_5.sce
new file mode 100755
index 000000000..2b130aef7
--- /dev/null
+++ b/2223/CH18/EX18.5/Ex18_5.sce
@@ -0,0 +1,30 @@
+// scilab Code Exa 18.5 Calculation on a Draft Tube 
+
+c2=6.25; // exit velocity in m/s
+ro=1e3; // density in kg/m3
+g=9.81; // Gravitational acceleration in m/s^2
+AR=1.6; // Area Ratio of Diffuser
+Q=100; // discharge in m3/s
+n_D=0.82; // Efficiency of the Draft Tube
+
+// part(a)
+c1=c2*AR;
+A1=Q/c1;
+disp("m2",A1,"(a)area of cross-section at entry is")
+A2=A1*AR;
+disp("m2",A2,"and the area of cross-section at exit is")
+
+// part(b)
+delHi=((c1^2)-(c2^2))/(2*g);
+delH_a=delHi*n_D;
+disp("m",delH_a,"(b)actual head gained by the Draft Tube is")
+
+// part(c)
+m=ro*Q;
+delP_a=m*g*delH_a;
+disp("MW",delP_a*1e-6,"(c)the additional power generated is")
+
+// part(d)
+Loss=delHi-delH_a;
+disp("m",Loss,"(d)the loss of head due to losses in the draft tube is")
+
diff --git a/2223/CH18/EX18.50/Ex18_50.sav b/2223/CH18/EX18.50/Ex18_50.sav
new file mode 100755
index 000000000..c2667951a
--- /dev/null
+++ b/2223/CH18/EX18.50/Ex18_50.sav
diff --git a/2223/CH18/EX18.50/Ex18_50.sce b/2223/CH18/EX18.50/Ex18_50.sce
new file mode 100755
index 000000000..fbcd99022
--- /dev/null
+++ b/2223/CH18/EX18.50/Ex18_50.sce
@@ -0,0 +1,27 @@
+// scilab Code Exa 18.50 Centrifugal pump 1500 rpm
+
+N=1500; // rotor Speed in RPM
+H=5.2; // head in m
+b=2/100; // width in m
+d1=2.5/100; // entry diameter of the blade ring in m
+d2=0.1; // exit diameter of the blade ring in m
+rho=1e3;
+g=9.81; // Gravitational acceleration in m/s^2
+n_o=0.75; // overall Efficiency of the drive
+u2=%pi*d2*N/60;
+u1=u2*d1/d2;
+// part(a)impeller blade angle at the entry
+c_r2=0.4*u2;
+c_r1=c_r2*d2/d1;
+beta1=atand(c_r1/u1);
+disp("degree",beta1,"(a)the impeller blade angle at the entry beta1=")
+//part(b) discharge
+Q=c_r1*%pi*d1*b;
+disp("litres/sec",Q*1e3,"(b)the discharge is")
+//part(c)Power required
+P=(rho*Q*g*H)/(n_o);
+disp("kW",P*1e-3,"(a)Power required to drive the pump is")
+// part(d)
+omega=%pi*2*N/60;
+NS=(H^(-3/4))*0.1804*(omega)*sqrt(Q);
+disp(NS,"(d)the specific speed is")
diff --git a/2223/CH18/EX18.51/Ex18_51.sav b/2223/CH18/EX18.51/Ex18_51.sav
new file mode 100755
index 000000000..4b0bf83cb
--- /dev/null
+++ b/2223/CH18/EX18.51/Ex18_51.sav
diff --git a/2223/CH18/EX18.51/Ex18_51.sce b/2223/CH18/EX18.51/Ex18_51.sce
new file mode 100755
index 000000000..eb25b0c62
--- /dev/null
+++ b/2223/CH18/EX18.51/Ex18_51.sce
@@ -0,0 +1,30 @@
+// scilab Code Exa 18.51 Axial pump 360 rpm
+
+N=360; // rotor Speed in RPM
+dh=0.30; // hub diameter of the impeller in m
+beta2=48; // exit angle of the runner blades(from the tangential direction)
+cx=5; // axial velocity of water through the impeller in m/s
+n_h=0.87; // hydraulic efficiency
+n_o=0.83; // overall Efficiency 
+Q=2.5; // discharge in m3/s
+rho=1e3;
+g=9.81; // Gravitational acceleration in m/s^2
+//part(a)
+dt=sqrt((4*Q/(cx*%pi))+(dh^2));
+disp("m",dt,"(a)the impeller tip diameter is")
+// part(b)impeller blade angle at the entry
+d=0.5*(dt+dh); // mean diameter of the impeller blade in m
+u=%pi*d*N/60;
+beta1=atand(cx/u);
+disp("degree",beta1,"(b)the impeller blade angle at the entry beta1=")
+// part(c)
+cy2=u-(cx/tand(beta2));
+H=n_h*u*cy2/g;
+disp("m",H,"(c)the head developed is")
+//part(d)Power required
+P=(rho*Q*g*H)/(n_o);
+disp("kW",P*1e-3,"(d)Power required to drive the pump is")
+// part(e)
+omega=%pi*2*N/60;
+NS=(H^(-3/4))*0.1804*(omega)*sqrt(Q);
+disp(NS,"(e)the specific speed is")
diff --git a/2223/CH18/EX18.52/Ex18_52.sav b/2223/CH18/EX18.52/Ex18_52.sav
new file mode 100755
index 000000000..d305112ae
--- /dev/null
+++ b/2223/CH18/EX18.52/Ex18_52.sav
diff --git a/2223/CH18/EX18.52/Ex18_52.sce b/2223/CH18/EX18.52/Ex18_52.sce
new file mode 100755
index 000000000..576f2ebb7
--- /dev/null
+++ b/2223/CH18/EX18.52/Ex18_52.sce
@@ -0,0 +1,38 @@
+// scilab Code Exa 18.52 NPSH for Centrifugal pump
+
+H=30; // head developed in m
+ds=0.15; // suction pipe diameter in m
+f=0.005; //Coefficient of friction for the suction pipe
+pa=1.013; // atmospheric pressure in bar
+As=%pi/4*(ds^2); // Cross-sectional Area of the suction pipe in m2
+rho=1e3; // density of water in kg/m3
+g=9.81; // Gravitational acceleration in m/s^2
+t=30; // temperature of water in degree C
+pv=0.0424; // vapour pressure of water at t value
+Hv=pv*1e5/(rho*g);
+Z(1)=0; // altitude in m
+Z(2)=2500;
+p(1)=pa; // at altitude Z=0
+p(2)=0.747; // at Z=2500m
+Q(1)=0.065; // discharge in m3/s of water
+Q(2)=0.1;
+Q(3)=0.15;
+Hs(1)=3; // vertical length of the suction pipe in m
+Hs(2)=5;
+for i=1:3
+    disp("m3/s",Q(i),"when Q=")
+    cs=Q(i)/As;
+    for k=1:2
+        disp("m",Hs(k),"and Hs=")
+        delHf=4*f*(Hs(k)/ds)*(cs^2/(2*g));
+        for j=1:2
+        disp("m",Z(j),"and Z=")
+        Ha=p(j)*1e5/(rho*g);
+    H1=Ha-(Hs(k)+(cs^2/(2*g))+delHf);
+    NPSH=H1-Hv;
+disp(NPSH,"NPSH=")
+sigma=NPSH/H;
+disp(sigma,"Cavitation Coefficient sigma=")
+end
+end
+end
diff --git a/2223/CH18/EX18.53/Ex18_53.sav b/2223/CH18/EX18.53/Ex18_53.sav
new file mode 100755
index 000000000..9b204149b
--- /dev/null
+++ b/2223/CH18/EX18.53/Ex18_53.sav
diff --git a/2223/CH18/EX18.53/Ex18_53.sce b/2223/CH18/EX18.53/Ex18_53.sce
new file mode 100755
index 000000000..f41f1b55d
--- /dev/null
+++ b/2223/CH18/EX18.53/Ex18_53.sce
@@ -0,0 +1,28 @@
+// scilab Code Exa 18.53 NPSH and Thoma Cavitation Coefficient
+
+H=60; // head developed in m
+c1=8; // exit velocity in m/s
+pa=1.0133; // ambient pressure in bar
+rho=1e3;
+n_d=0.8; // Efficiency of the Draft Tube
+g=9.81; // Gravitational acceleration in m/s^2
+ta=30; // ambient temperature of water in degree C
+pv=0.0424; // vapour pressure of water at t value
+Hv=pv*1e5/(rho*g);
+//Q=c1*A1=c2*A2
+Ar(1)=1.2; // draft tube area ratio(A2/A1=c1/c2)
+Ar(2)=1.4;
+Ar(3)=1.6;
+Hs=2.5; // vertical length of the draft tube between the turbine exit and the tail race in m
+Ha=pa*1e5/(rho*g);
+for i=1:3
+    Hsd=(c1^2)*(1-(1/(Ar(i)^2)))/(2*g); // ideal head gained by the draft tube
+    Hd=n_d*Hsd; //Actual head gained by the draft tube
+    disp(Ar(i),"for Area Ratio Ar=")
+    disp("m",Hd,"(a)Actual head gained by the draft tube is")
+    H1=Ha-(Hs+Hd);
+    NPSH=H1-Hv;
+disp(NPSH,"(b)NPSH=")
+sigma=NPSH/H;
+disp(sigma,"and Cavitation parameter(Thoma Number) sigma=")
+end
diff --git a/2223/CH18/EX18.54/Ex18_54.sav b/2223/CH18/EX18.54/Ex18_54.sav
new file mode 100755
index 000000000..59398915d
--- /dev/null
+++ b/2223/CH18/EX18.54/Ex18_54.sav
diff --git a/2223/CH18/EX18.54/Ex18_54.sce b/2223/CH18/EX18.54/Ex18_54.sce
new file mode 100755
index 000000000..b1b8fe578
--- /dev/null
+++ b/2223/CH18/EX18.54/Ex18_54.sce
@@ -0,0 +1,34 @@
+// scilab Code Exa 18.54 Maximum Height of Hydro Turbines
+
+H=52; // head developed in m
+c1=6.5; // exit velocity in m/s
+pa=1.0133; // ambient pressure in bar
+rho=1e3;
+n_d=0.75; // Efficiency of the Draft Tube
+g=9.81; // Gravitational acceleration in m/s^2
+ta=20; // ambient temperature of water in degree C
+sigma_cr=0.1;
+pv=0.023; // vapour pressure of water at t value(from tables)
+Hv=pv*1e5/(rho*g);
+//Q=c1*A1=c2*A2
+Ar=1.5; // draft tube area ratio(A2/A1=c1/c2)
+Z(1)=0; // altitude in m
+Z(2)=2500;
+Z(3)=3000;
+Z(4)=4000;
+p(1)=pa; // at altitude Z=0
+p(2)=0.747; // at Z=2500m
+p(3)=0.701; // at altitude Z=3000m
+p(4)=0.657; // at Z=4000m
+ Hsd=(c1^2)*(1-(1/(Ar^2)))/(2*g); // ideal head gained by the draft tube
+    Hd=n_d*Hsd; //Actual head gained by the draft tube
+Ha=pa*1e5/(rho*g);
+for i=1:4
+        disp("m",Z(i),"For Z=")
+        Ha=p(i)*1e5/(rho*g);
+    H1=Ha-(Hsd+Hd);
+    Hs=Ha-((sigma_cr*H)+Hd+Hv); // vertical length of the draft tube between the turbine exit and the tail race in m
+    disp("m",Hs,"the maximum height of the turbine exit above the tail race is")
+    NPSH=sigma_cr*H;
+disp(NPSH,"NPSH=")
+end
diff --git a/2223/CH18/EX18.55/Ex18_55.sav b/2223/CH18/EX18.55/Ex18_55.sav
new file mode 100755
index 000000000..19412836e
--- /dev/null
+++ b/2223/CH18/EX18.55/Ex18_55.sav
diff --git a/2223/CH18/EX18.55/Ex18_55.sce b/2223/CH18/EX18.55/Ex18_55.sce
new file mode 100755
index 000000000..37d57d471
--- /dev/null
+++ b/2223/CH18/EX18.55/Ex18_55.sce
@@ -0,0 +1,23 @@
+// scilab Code Exa 18.55 Propeller Thrust and Power
+
+c_u=5; // upstream velocity in m/s
+c_s=10; // downstream velocity in m/s
+rho=1e3; // density of water in kg/m3
+c=0.5*(c_u+c_s); // velocity of water through the propeller in m/s
+d(1)=0.5; // propeller diameter in m
+d(2)=1;
+d(3)=1.5;
+delh_0=0.5*((c_s^2)-(c_u^2));
+delp_0=rho*delh_0;
+disp("bar",delp_0*1e-5,"(b)stagnation pressure rise across the propeller is")
+for i=1:3
+    disp("cm",d(i)*1e2,"for propeller diameter=")
+A=%pi*(d(i)^2)/4;
+Q=c*A;
+m=rho*Q;
+disp("m3/s",Q,"(a) flow rate through the propeller is")
+Fx=A*delp_0;
+disp("kN",Fx*1e-3,"(c) thrust exerted by the propeller on the boat is")
+P=m*delh_0;
+disp("kW",P/1000,"(d)the ideal Power required to drive the propeller is")
+end
diff --git a/2223/CH18/EX18.6/Ex18_6.sav b/2223/CH18/EX18.6/Ex18_6.sav
new file mode 100755
index 000000000..14b55d840
--- /dev/null
+++ b/2223/CH18/EX18.6/Ex18_6.sav
diff --git a/2223/CH18/EX18.6/Ex18_6.sce b/2223/CH18/EX18.6/Ex18_6.sce
new file mode 100755
index 000000000..fae4d033b
--- /dev/null
+++ b/2223/CH18/EX18.6/Ex18_6.sce
@@ -0,0 +1,30 @@
+// scilab Code Exa 18.6 Calculations on a Gas Turbine 
+
+m=472; // flow rate of hot gases in kg/s
+T01=1335;  // Turbine inlet temp in Kelvin
+p01=10; // Turbine Inlet Pressure in bar
+c2=150; // exit velocity in m/s
+pr0=10; // Turbine pressure ratio
+gamma_g=1.67;
+T2=560;  // Temperature of gases at exit in Kelvin
+cp_g=1.157; // Specific Heat of gas at Constant Pressure in kJ/(kgK)
+
+// part(a) Determining total to total efficiency
+T02=T2+(0.5*(c2^2)/(cp_g*1e3));
+T02s=T01/(pr0^((gamma_g-1)/gamma_g));
+n_tt=(T01-T02)/(T01-T02s);
+disp("%",n_tt*100,"(a)total to total efficiency is")
+
+
+// part(b) Determining total to static efficiency
+T2s=T02s-(0.5*(c2^2)/(cp_g*1e3));
+n_ts=(T01-T02)/(T01-T2s);
+disp("%",n_ts*100,"(b)total to static efficiency is")
+
+// part(c) Determining the polytropic efficiency
+n_p=((gamma_g)/(gamma_g-1))*((log(T01/T02))/(log(pr0)));
+disp("%",n_p*100,"(c)polytropic efficiency is")
+
+// part(d) Determining power developed by the turbine
+P=m*cp_g*(T01-T02);
+disp("MW",P/1e3,"(d)Power developed by the turbine is")
diff --git a/2223/CH18/EX18.7/Ex18_7.sav b/2223/CH18/EX18.7/Ex18_7.sav
new file mode 100755
index 000000000..7e0a15356
--- /dev/null
+++ b/2223/CH18/EX18.7/Ex18_7.sav
diff --git a/2223/CH18/EX18.7/Ex18_7.sce b/2223/CH18/EX18.7/Ex18_7.sce
new file mode 100755
index 000000000..cbf36c7ff
--- /dev/null
+++ b/2223/CH18/EX18.7/Ex18_7.sce
@@ -0,0 +1,25 @@
+// scilab Code Exa 18.7 RHF of a three stage turbine
+
+p1=1.0; // Initial Pressure in bar
+gamma=1.4;
+T1=1500;  // Initial Temperature in K
+s=3; // number of stages
+opr=11; // Overall Pressure Ratio
+pr=opr^(1/s); // equal Pressure Ratio in each stage
+n_T=0.88; // Overall Efficiency 
+delTa=T1*(1-opr^(-((gamma-1)/gamma)))*n_T;
+T2=T1-delTa;
+n_p=(log(T1/T2))/(((gamma-1)/gamma)*(log(opr))); // polytropic or small stage efficiency
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+n_st=(1-pr^(n_p*(-((gamma-1)/gamma))))/(1-pr^(-((gamma-1)/gamma))); // stage efficiency
+T(1)=T1;
+for i=1:3
+    delT(i)=T(i)*(1-pr^(n_p*(-((gamma-1)/gamma))));
+    delw_s(i)=delT(i)*cp/n_st;
+    T(i+1)=T(i)-delT(i);
+end
+w_a=cp*delTa;
+w_s=w_a/n_T;
+RHF=(delw_s(1)+delw_s(2)+delw_s(3))/w_s;
+disp(RHF,"the reheat factor is")
+
diff --git a/2223/CH18/EX18.8/Ex18_8.sav b/2223/CH18/EX18.8/Ex18_8.sav
new file mode 100755
index 000000000..0fa3ca754
--- /dev/null
+++ b/2223/CH18/EX18.8/Ex18_8.sav
diff --git a/2223/CH18/EX18.8/Ex18_8.sce b/2223/CH18/EX18.8/Ex18_8.sce
new file mode 100755
index 000000000..b39ea15f3
--- /dev/null
+++ b/2223/CH18/EX18.8/Ex18_8.sce
@@ -0,0 +1,35 @@
+// scilab Code Exa 18.8 Calculation on an air compressor
+
+funcprot(0)
+p1=1.0; // Initial Pressure in bar
+T1=305;  // Initial Temperature in degree K
+k=16; // number of stages
+m=400; // mass flow rate through the compressor in kg/s
+p_rc=10; // overall Pressure Ratio
+gamma=1.4; // Specific Heat Ratio
+cp=1.005; // Specific Heat at Constant Pressure in kJ/(kgK)
+n_p=0.88; // polytropic efficiency
+
+// part(a) Determining stage Pressure Ratio
+pr=p_rc^(1/k);
+disp(pr,"(a)stage Pressure Ratio is")
+
+// part(b) Determining the stage efficiency
+T2s=T1*(pr^((gamma-1)/gamma));
+T2=T1*(pr^((gamma-1)/(gamma*n_p)));
+n_st=(T2s-T1)/(T2-T1);
+disp("%",n_st*100,"(b)stage Efficiency of the compressor is")
+
+// part(c) Determining power required for the first stage
+P1=m*cp*(T2-T1);
+disp ("MW",P1/1e3,"(c)Power required for the first stage is")
+
+// part(d)Overall Compressor Efficiency
+T17=T1*exp(((gamma-1)/(gamma*n_p))*(log(p_rc))); // k+1=17;
+T17s=T1*(p_rc^((gamma-1)/gamma));
+n_C=(T17s-T1)/(T17-T1);
+disp ("%",n_C*100,"(d)Overall Compressor Efficiency is")
+
+// part(e) Determining power required to drive the compressor
+P=m*cp*(T17-T1);
+disp ("MW",P/1e3,"(e)Power required to drive the compressor is")
diff --git a/2223/CH18/EX18.9/Ex18_9.sav b/2223/CH18/EX18.9/Ex18_9.sav
new file mode 100755
index 000000000..ed8a93741
--- /dev/null
+++ b/2223/CH18/EX18.9/Ex18_9.sav
diff --git a/2223/CH18/EX18.9/Ex18_9.sce b/2223/CH18/EX18.9/Ex18_9.sce
new file mode 100755
index 000000000..4e07f3e37
--- /dev/null
+++ b/2223/CH18/EX18.9/Ex18_9.sce
@@ -0,0 +1,50 @@
+// scilab Code Exa 18.9 Constant Pressure Gas Turbine Plant
+
+T1=298; // Minimum Temperature in Kelvin
+beeta=4.5; // Maximum to Minimum Temperature ratio(T_max/T_min)
+m=115; // mass flow rate through the turbine and compressor in kg/s
+n_C=0.79; // Compressor Efficiency
+n_T=0.83; // Turbine Efficiency
+gamma_g=1.33;
+R=0.287;
+cp=(gamma_g/(gamma_g-1))*R; // Specific Heat at Constant Pressure in kJ/(kgK)
+alpha=beeta*n_C*n_T;
+t_opt=sqrt(alpha); // For maximum power output, the temperature ratios in the turbine and compressor
+
+// part(a) Determining optimum pressure ratio of the plant
+r=t_opt^(gamma_g/(gamma_g-1));
+disp(r,"(a)optimum pressure ratio of the plant is")
+
+// part(b)Carnot's efficiency
+n_Carnot=1-(1/beeta);
+disp("%",n_Carnot*100,"(b)Carnot efficiency of the plant is")
+
+// part(c) Determining Joule's cycle efficiency
+n_Joule=1-(1/t_opt);
+disp("%",n_Joule*100,"(c)efficiency of the Joule cycle is")
+
+// part(d) Determining thermal efficiency of the plant for maximum power output
+n_th=(t_opt-1)^2/((beeta-1)*n_C-(t_opt-1));
+disp("%",n_th*100,"(d)thermal efficiency of the plant for maximum power output is")
+
+// part(e) Determining power output
+wp_max=cp*T1*((t_opt-1)^2)/n_C; // maximum work output
+P_max=m*wp_max;
+disp ("MW",P_max/1e3,"(e)Power output is")
+
+// part(f) Determining power generated by the turbine required to drive the compressor
+T3=beeta*T1;  // Maximum Temperature in degree K
+T4s=T3*(r^(-((gamma_g-1)/gamma_g)));
+T4=T3-((T3-T4s)*n_T);
+P_T=m*cp*(T3-T4);
+disp ("MW",P_T/1e3,"(f)Power generated by the turbine is")
+
+// part(g) Determining power absorbed by the compressor
+T2s=T1*(r^((gamma_g-1)/gamma_g));
+T2=T1+((T2s-T1)/n_C);
+P_C=m*cp*(T2-T1);
+disp ("MW",P_C/1e3,"(g)Power absorbed by the compressor is")
+
+//part(h)heat supplied in the combustion chamber
+Qs=m*cp*(T3-T2);
+disp("MW",Qs/1e3,"(h)heat supplied in the combustion chamber is")