diff options
| author | priyanka | 2015-06-24 15:03:17 +0530 |
|---|---|---|
| committer | priyanka | 2015-06-24 15:03:17 +0530 |
| commit | b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b (patch) | |
| tree | ab291cffc65280e58ac82470ba63fbcca7805165 /551/CH13 | |
| download | Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.gz Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.bz2 Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.zip | |
initial commit / add all books
Diffstat (limited to '551/CH13')
47 files changed, 1690 insertions, 0 deletions
diff --git a/551/CH13/EX13.1/1.sce b/551/CH13/EX13.1/1.sce new file mode 100755 index 000000000..450b4c5e2 --- /dev/null +++ b/551/CH13/EX13.1/1.sce @@ -0,0 +1,24 @@ +clc
+T1=671; //K
+T2=T1;
+T3=313; //K
+T4=T3;
+W=130; //kJ
+
+disp("(i) Engine thermal efficiency =")
+n_th=(T2-T3)/T2;
+disp(n_th)
+
+
+disp("(ii) Heat added =")
+Q=W/n_th;
+disp(Q)
+disp("kJ")
+
+
+disp("(iii) The entropy changes during heat rejection process")
+Q_rejected=Q-W;
+dS=Q_rejected/T3;
+disp("dS=")
+disp(dS)
+disp("kJ/K")
\ No newline at end of file diff --git a/551/CH13/EX13.10/10.sce b/551/CH13/EX13.10/10.sce new file mode 100755 index 000000000..2c41c5b4a --- /dev/null +++ b/551/CH13/EX13.10/10.sce @@ -0,0 +1,44 @@ +clc
+r=6; //v1/v2=v4/v3=r
+p1=1; //bar
+T1=300; //K
+T3=1842; //K
+y=1.4;
+
+disp("(i) Temperature and pressure after the isentropic expansion")
+p2=p1*(r)^y;
+T2=T1*r^(y-1);
+p3=p2*(T3/T2);
+
+T4=T3/r^(y-1);
+disp("T4=")
+disp(T4)
+disp("K")
+
+p4=p3/(r)^(y);
+disp("p4 =")
+disp(p4)
+disp("bar")
+
+disp("(ii) Process required to complete the cycle")
+
+disp("Process required to complete the cycle is the constant pressure scavenging. The cycle is called Atkinson cycle")
+
+disp("(iii) Percentage improvement/increase in efficiency")
+p5=1; //bar
+T5=T3*(p5/p3)^((y-1)/y);
+
+n_otto=(1-1/r^(y-1))*100;
+disp("n_otto = ")
+disp(n_otto)
+disp("%")
+
+n_atkinson=(1-y*(T5-T1)/(T3-T2))*100;
+disp("n_atkinson=")
+disp(n_atkinson)
+disp("%")
+
+dn=n_atkinson - n_otto; //Improvement in efficiency
+disp("Improvement in efficiency =")
+disp(dn)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.11/11.sce b/551/CH13/EX13.11/11.sce new file mode 100755 index 000000000..c3fc6cf66 --- /dev/null +++ b/551/CH13/EX13.11/11.sce @@ -0,0 +1,25 @@ +clc
+p1=1; //bar
+T1=343; //K
+p2=7; //bar
+Qs=465; //kJ/kg of air
+cp=1; //kJ/kg K
+cv=0.706; //kJ/kg K
+y=1.41;
+
+disp("(i) Compression ratio of engine =")
+r=(p2/p1)^(1/y);
+disp(r)
+
+
+disp("(ii) Temperature at the end of compression =")
+T2=T1*(r)^(y-1);
+t2=T2-273;
+disp(t2)
+disp("0C")
+
+disp("(iii) Temperature at the end of heat addition =")
+T3=Qs/cv+T2;
+t3=T3-273;
+disp(t3)
+disp("0C")
diff --git a/551/CH13/EX13.12/12.sce b/551/CH13/EX13.12/12.sce new file mode 100755 index 000000000..2798c8b39 --- /dev/null +++ b/551/CH13/EX13.12/12.sce @@ -0,0 +1,29 @@ +clc
+
+y=1.4;
+R=0.287; //kJ/kg K
+T1=311; //K
+T3=2223; //K
+//p2/p1=15
+
+disp("(i) Compression ratio =")
+r=15^(1/1.4);
+disp(r)
+
+
+disp("(ii) Thermal efficiency =")
+n_th=1-1/r^(y-1);
+disp(n_th)
+
+disp("(iii) Work done")
+T2=T1*(r)^(y-1);
+T4=T3/r^(y-1);
+cv=R/(y-1);
+
+Q_supplied=cv*(T3-T2);
+Q_rejected=cv*(T4-T1);
+
+W=Q_supplied-Q_rejected;
+disp("Work done=")
+disp(W)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH13/EX13.13/13.sce b/551/CH13/EX13.13/13.sce new file mode 100755 index 000000000..f941e0f20 --- /dev/null +++ b/551/CH13/EX13.13/13.sce @@ -0,0 +1,78 @@ +clc
+V1=0.45; //m^3
+p1=1; //bar
+T1=303; //K
+p2=11; //bar
+Qs=210; //kJ
+n=210; //number of working cycles/min
+R=287; //J/kg K
+cv=0.71; //kJ/kg K
+y=1.4;
+
+disp("(i) Pressures, temperatures and volumes at salient points")
+r=(p2/p1)^(1/y);
+
+T2=T1*(r)^(y-1);
+disp("T2=")
+disp(T2)
+disp("K")
+
+V2=T2/T1*p1/p2*V1;
+disp("V2=")
+disp(V2)
+disp("m^3")
+
+m=p1*10^5*V1/R/T1;
+T3=Qs/m/cv+T2;
+disp("T3=")
+disp(T3)
+disp("K")
+
+p3=T3/T2*p2;
+disp("p3=")
+disp(p3)
+disp("bar")
+
+V3=V2;
+disp("V3=")
+disp(V3)
+disp("m^3")
+
+p4=p3/r^y;
+disp("p4=")
+disp(p4)
+disp("bar")
+
+T4=T3/r^(y-1);
+disp("T4=")
+disp(T4)
+disp("K")
+
+V4=V1;
+disp("V4=")
+disp(V4)
+disp("m^3")
+
+
+disp("(ii) Percentage clearance =")
+%clearance=V2/(V1-V2)*100;
+disp(%clearance)
+disp("%")
+
+
+disp("(iii) Efficiency =")
+Qr=m*cv*(T4-T1);
+n_otto=(Qs-Qr)/Qs;
+disp(n_otto)
+
+
+disp("(iv) Mean effective pressure =")
+p_m=(Qs-Qr)/(V1-V2)/100; //bar
+disp(p_m)
+disp("bar")
+
+
+disp("(v) Power developed =")
+P=(Qs-Qr)*n/60;
+disp(P)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.14/14.sce b/551/CH13/EX13.14/14.sce new file mode 100755 index 000000000..cdcd079d5 --- /dev/null +++ b/551/CH13/EX13.14/14.sce @@ -0,0 +1,39 @@ +clc
+
+// W=Qs-Qr=cv*(T3-T2) - cv*(T4-T1)
+// T2=T1*(r^(y-1))
+// T3=T4*(r^(y-1))
+// W=cv*[T3-T1*r^(y-1) - T3/r^(y-1)+T1];
+// dW/dr=-T1*(y-1)*r^(y-2) - T3*(1-y)*r^(-y)=0
+
+//By solving this we get
+
+disp("r=(T3/T1)^(1/2/(y-1))")
+
+disp("(b)Change in efficiency")
+
+T3=1220; //K
+T1=310; //K
+
+// For air
+y=1.4;
+r1=(T3/T1)^(1/2/(y-1));
+n1=1-1/r1^(y-1); //air standard Efficiency
+disp("Air standard Efficiency =")
+disp(n1)
+
+//For helium
+cp=5.22; //kJ/kg K
+cv=3.13; //kJ/kg K
+y=cp/cv;
+r2=(T3/T1)^(1/2/(y-1));
+
+n2=1-1/r2^(y-1);
+disp("Air standard efficiency for helium =")
+disp(n2)
+
+change=n1-n2;
+disp("Change in efficiency=")
+disp(change)
+
+disp("Hence change in efficiency is nil")
\ No newline at end of file diff --git a/551/CH13/EX13.15/15.sce b/551/CH13/EX13.15/15.sce new file mode 100755 index 000000000..a7aeb5aad --- /dev/null +++ b/551/CH13/EX13.15/15.sce @@ -0,0 +1,32 @@ +clc
+// W=cv*[T3-T1*r^(y-1) - T3/r^(y-1)+T1]
+// r=(T3/T1)^(1/2/(y-1))
+// T2=T1*r^(y-1)
+// T4=T3/r^(y-1)
+
+// T2=T1*[(T3/T1)^(1/2/(y-1))]^(y-1)
+
+
+//T2=sqrt(T1*T3)
+
+//Similarly T4=T3/[(T3/T1)^(1/2/(y-1))]^(y-1)
+//T4=sqrt(T1*T3)
+
+disp("T2=T4=sqrt(T1*T3)")
+
+
+disp("(b) Power developed ")
+T1=310; //K
+T3=1450; //K
+m=0.38; //kg
+cv=0.71; //kJ/kg K
+
+T2=sqrt(T1*T3);
+T4=T2;
+
+W1=cv*[(T3-T2) - (T4-T1)]; //Work done
+W=m/60*W1; //Work done per second
+
+disp("Power =")
+disp(W)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.17/17.sce b/551/CH13/EX13.17/17.sce new file mode 100755 index 000000000..ef5ba6174 --- /dev/null +++ b/551/CH13/EX13.17/17.sce @@ -0,0 +1,10 @@ +clc
+r=15;
+y=1.4;
+
+//V3-V2=0.06*(V1-V2)
+rho=1.84; //cut off ratio rho=V3/V2
+
+n_diesel=1-1/y/r^(y-1)*((rho^y-1)/(rho-1));
+disp("efficiency =")
+disp(n_diesel)
diff --git a/551/CH13/EX13.18/18.sce b/551/CH13/EX13.18/18.sce new file mode 100755 index 000000000..1fb6d1c68 --- /dev/null +++ b/551/CH13/EX13.18/18.sce @@ -0,0 +1,15 @@ +clc
+
+L=0.25; //m
+D=0.15; //m
+V2=0.0004; //m^3
+Vs=%pi/4*D^2*L;
+V_total=Vs+V2;
+y=1.4;
+V3=V2+5/100*Vs;
+rho=V3/V2;
+r=(Vs+V2)/V2; //V1=Vs+V2
+
+n_diesel=1-1/y/r^(y-1)*((rho^y-1)/(rho-1));
+disp("efficiency =")
+disp(n_diesel)
\ No newline at end of file diff --git a/551/CH13/EX13.19/19.sce b/551/CH13/EX13.19/19.sce new file mode 100755 index 000000000..25f36a543 --- /dev/null +++ b/551/CH13/EX13.19/19.sce @@ -0,0 +1,16 @@ +clc
+r=14; //let clearance volume be unity
+y=1.4;
+
+//When the fuel is cut-off at 5%
+rho1=5/100*(r-1)+1;
+n_diesel1=1-1/y/r^(y-1)*((rho1^y-1)/(rho1-1));
+
+//When the fuel is cut-off at 8%
+rho2=8/100*(r-1)+1;
+n_diesel2=1-1/y/r^(y-1)*((rho2^y-1)/(rho2-1));
+
+%loss=(n_diesel1-n_diesel2)*100;
+disp("percentage loss in efficiency due to delay in fuel cut off =")
+disp(%loss)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.2/2.sce b/551/CH13/EX13.2/2.sce new file mode 100755 index 000000000..dcd8dac1a --- /dev/null +++ b/551/CH13/EX13.2/2.sce @@ -0,0 +1,46 @@ +clc
+cv=0.721; //kJ/kg K
+cp=1.008; //kJ/kg K
+m=0.5; //kg
+n_th=0.5;
+Q_isothermal=40; //kJ
+p1=7*10^5; //Pa
+V1=0.12; //m^3
+R=287; //J/kg K
+
+disp("(i) The maximum and minimum temperatures")
+T1=p1*V1/m/R;
+disp("Maximun temperature =")
+disp(T1)
+disp("K")
+
+T2=(1-n_th)*T1;
+disp("Minimum temperature =")
+disp(T2)
+disp("K")
+
+
+disp("(ii) The volume at the end of isothermal expansion =")
+V2=V1*%e^(Q_isothermal*10^3/m/R/T1);
+disp(V2)
+disp("m^3")
+
+
+disp("(iii) The heat transfer for each of the four processes")
+
+Q1=Q_isothermal;
+disp("Isothermal expansion")
+disp(Q1)
+disp("kJ")
+
+Q2=0;
+disp("Adiabatic reversible expansion")
+disp(Q2)
+
+Q3=-Q_isothermal;
+disp("Isothermal compression")
+disp(Q3)
+
+Q4=0;
+disp("Adiabatic reversible compression")
+disp(Q4)
\ No newline at end of file diff --git a/551/CH13/EX13.20/20.sce b/551/CH13/EX13.20/20.sce new file mode 100755 index 000000000..9e2ade33a --- /dev/null +++ b/551/CH13/EX13.20/20.sce @@ -0,0 +1,15 @@ +clc
+
+pm=7.5; //bar
+r=12.5;
+p1=1; //bar
+y=1.4;
+
+// pm = p1*r^y*[y*(rho-1) - r^(1-y)*(rho^y-1)]/(y-1)/(r-1)
+//Solving above equation we get
+rho=2.24;
+
+%cutoff=(rho-1)/(r-1)*100;
+disp("%cutoff=")
+disp(%cutoff)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.21/21.sce b/551/CH13/EX13.21/21.sce new file mode 100755 index 000000000..3afd2c579 --- /dev/null +++ b/551/CH13/EX13.21/21.sce @@ -0,0 +1,81 @@ +clc
+D=0.2; //m
+L=0.3; //m
+p1=1; //bar
+T1=300; //K
+R=287;
+r=15;
+y=1.4;
+
+disp("(i) Pressures and temperatures at salient points")
+Vs=%pi/4*D^2*L;
+
+V1=r/(r-1)*Vs;
+disp("V1=")
+disp(V1)
+disp("m^3")
+
+m=p1*10^5*V1/R/T1;
+
+p2=p1*r^y;
+disp("p2=")
+disp(p2)
+disp("bar")
+
+T2=T1*r^(y-1);
+disp("T2=")
+disp(T2)
+disp("K")
+
+V2=Vs/(r-1);
+disp("V2=")
+disp(V2)
+disp("m^3")
+
+rho=8/100*(r-1) + 1;
+V3=rho*V2;
+disp("V3=")
+disp(V3)
+disp("m^3")
+
+T3=T2*V3/V2;
+disp("T3=")
+disp(T3)
+disp("K")
+
+p3=p2;
+disp("p3=")
+disp(p3)
+disp("bar")
+
+p4=p3*(rho/r)^y;
+disp("p4=")
+disp(p4)
+disp("bar")
+
+T4=T3*(rho/r)^(y-1);
+disp("T4=")
+disp(T4)
+disp("K")
+
+V4=V1;
+disp("V4=")
+disp(V4)
+disp("m^3")
+
+disp("(ii) Theoretical air standard efficiency =")
+n_diesel=1-1/y/r^(y-1)*((rho^y-1)/(rho-1));
+disp("efficiency =")
+disp(n_diesel)
+
+
+disp("(iii) Mean effective pressure =")
+pm=(p1*r^y*(y*(rho-1) - r^(1-y)*(rho^y-1)))/(y-1)/(r-1);
+disp(pm)
+disp("bar")
+
+disp("(iv) Power of the engine =")
+n=380; //number of cycles per min
+P=n/60*pm*Vs*100; //kW
+disp(P)
+disp("kW")
diff --git a/551/CH13/EX13.22/22.sce b/551/CH13/EX13.22/22.sce new file mode 100755 index 000000000..40d145d54 --- /dev/null +++ b/551/CH13/EX13.22/22.sce @@ -0,0 +1,46 @@ +clc
+r1=15.3; //V1/V2
+r2=7.5; //V4/V3
+p1=1; //bar
+T1=300; //K
+n_mech=0.8;
+C=42000; //kJ/kg
+y=1.4;
+R=287;
+cp=1.005;
+cv=0.718;
+V2=1; ////Assuming V2=1 m^3
+
+T2=T1*r1^(y-1);
+p2=p1*r1^y;
+T3=r1/r2*T2;
+m=p2*10^5*V2/R/T2;
+T4=T3/r2^(y-1);
+
+Q_added=m*cp*(T3-T2);
+Q_rejected=m*cv*(T4-T1);
+W=Q_added-Q_rejected;
+
+pm=W/(r1-1)/V2/100;
+disp("Mean effective pressure =")
+disp(pm)
+disp("bar")
+
+ratio=p2/pm;
+disp("Ratio of maximum pressure to mean effective pressure =")
+disp(ratio)
+
+n_cycle=W/Q_added;
+disp("Cycle efficiency =")
+disp(n_cycle)
+
+n_thI=0.5;
+n_cycle1=n_thI*n_cycle;
+
+n_thB=n_mech*n_cycle1;
+
+BP=1;
+mf=BP/C/n_thB*3600;
+disp("Fuel consumption per kWh =")
+disp(mf)
+disp("kg/kWh")
\ No newline at end of file diff --git a/551/CH13/EX13.23/23.sce b/551/CH13/EX13.23/23.sce new file mode 100755 index 000000000..20d2f678f --- /dev/null +++ b/551/CH13/EX13.23/23.sce @@ -0,0 +1,19 @@ +clc
+Vs=0.0053; //m^3
+Vc=0.00035; //m^3
+V3=Vc;
+V2=V3;
+p3=65; //bar
+p4=65; //bar
+T1=353; //K
+p1=0.9; //bar
+y=1.4;
+
+r=(Vs+Vc)/Vc;
+rho=(5/100*Vs+V3)/V3;
+p2=p1*(r)^y;
+B=p3/p2;
+
+n_dual=1-1/r^(y-1)*[(B*rho^y-1)/((B-1)+B*y*(rho-1))];
+disp("Efficiency of the cycle =")
+disp(n_dual)
\ No newline at end of file diff --git a/551/CH13/EX13.24/24.sce b/551/CH13/EX13.24/24.sce new file mode 100755 index 000000000..71a4283dd --- /dev/null +++ b/551/CH13/EX13.24/24.sce @@ -0,0 +1,9 @@ +clc
+r=14;
+B=1.4;
+rho=6/100*(r-1) + 1;
+y=1.4;
+
+n_dual=1-1/r^(y-1)*[(B*rho^y-1)/((B-1)+B*y*(rho-1))]
+disp("Efficiency of the cycle =")
+disp(n_dual)
\ No newline at end of file diff --git a/551/CH13/EX13.25/25.sce b/551/CH13/EX13.25/25.sce new file mode 100755 index 000000000..026f5cb9a --- /dev/null +++ b/551/CH13/EX13.25/25.sce @@ -0,0 +1,46 @@ +clc
+D=0.25; //m
+r=9;
+L=0.3; //m
+cv=0.71; //kJ/kg K
+cp=1; //kJ/kg K
+p1=1; //bar
+T1=303; //K
+p3=60; //bar
+p4=p3;
+n=3; //number of working cycles/ sec
+y=1.4;
+R=287;
+
+disp("(i) Air standard efficiency")
+Vs=%pi/4*D^2*L;
+
+Vc=Vs/(r-1);
+V1=Vs+Vc;
+p2=p1*(r)^y;
+T2=T1*r^(y-1);
+T3=T2*p3/p2;
+rho=4/100*(r-1)+1;
+T4=T3*rho;
+
+T5=T4*(rho/r)^(y-1);
+p5=p4*(r/rho)^(y);
+
+Qs=cv*(T3-T2)+cp*(T4-T3)
+
+Qr=cv*(T5-T1);
+
+n_airstandard=(Qs-Qr)/Qs;
+disp("efficiency =")
+disp(n_airstandard)
+
+
+disp("(ii) Power developed by the engine")
+m=p1*10^5*V1/R/T1;
+
+W=m*(Qs-Qr);
+
+P=W*n;
+disp("P=")
+disp(P)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.26/26.sce b/551/CH13/EX13.26/26.sce new file mode 100755 index 000000000..bcf833d65 --- /dev/null +++ b/551/CH13/EX13.26/26.sce @@ -0,0 +1,66 @@ +clc
+p1=1; //bar
+T1=363; //K
+r=9;
+p3=68; //bar
+p4=68; //bar
+Q=1750; //kJ/kg
+y=1.4;
+cv=0.71;
+cp=1.0;
+
+disp("(i) Pressures and temperatures at salient points")
+p2=p1*(r)^y;
+disp("p2=")
+disp(p2)
+disp("bar")
+
+T2=T1*r^(y-1);
+disp("T2=")
+disp(T2)
+disp("K")
+
+disp("p3=")
+disp(p3)
+disp("bar")
+
+disp("p4=")
+disp(p4)
+disp("bar")
+
+T3=T2*(p3/p2);
+disp("T3=")
+disp(T3)
+disp("K")
+
+Q1=cv*(T3-T2); //heat added at constant volume
+Q2=Q-Q1; //heat added at constant pressure
+
+T4=Q2/cp+T3;
+disp("T4=")
+disp(T4)
+disp("K")
+
+rho=T4/T3; //V4/V3=T4/T3
+
+p5=p4*(rho/r)^y;
+disp("p5=")
+disp(p5)
+disp("bar")
+
+T5=T4*(rho/r)^(y-1);
+disp("T5=")
+disp(T5)
+disp("K")
+
+
+disp("(ii) Air standard efficiency =")
+Qr=cv*(T5-T1);
+n_airstandard=(Q-Qr)/Q;
+disp(n_airstandard)
+
+
+disp("(iii) Mean effective pressure =")
+pm=1/(r-1)*(p3*(rho-1) + (p4*rho-p5*r)/(y-1) - (p2-p1*r)/(y-1));
+disp(pm)
+disp("bar")
diff --git a/551/CH13/EX13.27/27.sce b/551/CH13/EX13.27/27.sce new file mode 100755 index 000000000..edbbc6e33 --- /dev/null +++ b/551/CH13/EX13.27/27.sce @@ -0,0 +1,32 @@ +clc
+T1=300; //K
+r=15;
+y=1.4;
+//p3/p1=70
+
+T2=T1*(r)^(y-1);
+
+//p2/p1=r^y
+//p2=44.3*p1
+
+T3=1400; //K; T3=T2*p3/p2
+
+T4=T3 + (T3-T2)/y;
+
+//v1/v3=15
+//v4=0.084*v1
+//v5=v1
+//T5=T4*(v5/v1)^(y-1)
+T5=656.9; //K
+
+n_airstandard=1-(T5-T1)/((T3-T2) + y*(T4-T3));
+disp("Efficiency =")
+disp(n_airstandard)
+
+disp("Reasons for actual thermal efficiency being different from the theoretical value :")
+
+disp("1. In theoretical cycle working substance is taken air whereas in actual cycle air with fuel acts as working substance")
+
+disp("2. The fuel combustion phenomenon and associated problems like dissociation of gases, dilution of charge during suction stroke, etc. have not been taken into account")
+
+disp("3. Effect of variable specific heat, heat loss through cylinder walls, inlet and exhaust velocities of air/gas etc. have not been taken into account.")
\ No newline at end of file diff --git a/551/CH13/EX13.28/28.sce b/551/CH13/EX13.28/28.sce new file mode 100755 index 000000000..ea5a48a84 --- /dev/null +++ b/551/CH13/EX13.28/28.sce @@ -0,0 +1,41 @@ +clc
+T1=373; //K
+p1=1; //bar
+p3=65; //bar
+p4=p3;
+Vs=0.0085; //m^3
+ratio=21; //Air fuel ratio
+r=15;
+C=43890; //kJ/kg
+cp=1;
+cv=0.71;
+V2=0.0006; //m^3
+V1=0.009; //m^3
+y=1.41;
+V5=V1;
+V3=V2;
+R=287;
+
+p2=p1*(r)^y;
+T2=T1*r^(y-1);
+T3=T2*p3/p2;
+m=p1*10^5*V1/R/T1;
+
+Q1=m*cv*(T3-T2); //Heat added during constant volume process 2-3
+amt=Q1/C; //Amount of fuel added during the constant volume process 2-3
+total=m/ratio; //Total amount of fuel added
+quantity=total-amt; //Quantity of fuel added during the process 3-4
+
+Q2=quantity*C; //Heat added during constant pressure process
+
+T4=Q2/(m+total)/cp+T3;
+V4=V3*T4/T3;
+T5=T4*(V4/V5)^(y-1);
+
+Q3=(m+total)*cv*(T5-T1); //Heat rejected during constant volume process 5-1
+
+W=(Q1+Q2) - Q3;
+
+n_th=W/(Q1+Q2);
+disp("Thermal efficiency =")
+disp(n_th)
\ No newline at end of file diff --git a/551/CH13/EX13.29/29.sce b/551/CH13/EX13.29/29.sce new file mode 100755 index 000000000..69fc24891 --- /dev/null +++ b/551/CH13/EX13.29/29.sce @@ -0,0 +1,83 @@ +clc
+T1=303; //K
+p1=1; //bar
+rc=9;
+re=5;
+n=1.25;
+D=0.25; //m
+L=0.4; //m
+R=287;
+cv=0.71;
+cp=1;
+num=8; //no. 0f cycles/sec
+
+disp("(i) Pressure and temperatures at all salient points =")
+p2=p1*(rc)^n;
+disp("p2=")
+disp(p2)
+disp("bar")
+
+T2=T1*(rc)^(n-1);
+disp("T2=")
+disp(T2)
+disp("K")
+
+//T4=1.8*T3
+//Heat liberated at constant pressure= 2 × heat liberated at constant volume
+//cp*(T4-T3)=2*cv*(T3-T2)
+//T4/T3=1.8
+
+rho=rc/re;
+T3=1201.9; //K
+disp("T3=")
+disp(T3)
+disp("K")
+
+p3=p2*T3/T2;
+disp("p3=")
+disp(p3)
+disp("bar")
+
+p4=p3;
+disp("p4=")
+disp(p4)
+disp("bar")
+
+T4=1.8*T3;
+disp("T4=")
+disp(T4)
+disp("K")
+
+p5=p4*(1/re)^(n);
+disp("p5=")
+disp(p5)
+disp("bar")
+
+T5=T4*(1/re)^(n-1)
+disp("T5=")
+disp(T5)
+disp("K")
+
+
+disp("(ii) Mean effective pressure = ")
+pm=1/(rc-1)*[p3*(rho-1)+(p4*rho-p5*rc)/(n-1)-(p2-p1*rc)/(n-1)];
+disp(pm)
+disp("bar")
+
+disp("(iii) Efficiency of the cycle")
+Vs=%pi/4*D^2*L;
+W=pm*10^5*Vs/1000;
+
+V1=rc/(rc-1)*Vs
+m=p1*10^5*V1/R/T1;
+Q=m*(cv*(T3-T2) + cp*(T4-T3));
+
+Efficiency=W/Q;
+disp("Efficiency =")
+disp(Efficiency)
+
+
+disp("(iv) Power of the engine =")
+P=W*num;
+disp(P)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.3/3.sce b/551/CH13/EX13.3/3.sce new file mode 100755 index 000000000..a320b137f --- /dev/null +++ b/551/CH13/EX13.3/3.sce @@ -0,0 +1,63 @@ +clc
+p1=18*10^5; //Pa
+T1=683; //K
+T2=T1;
+r1=6; //ratio V4/V1; Isentropic compression
+r2=1.5; //ratio V2/V1; Isothermal expansion
+y=1.4;
+V1=0.18; //m^3
+
+disp("(i) Temperatures and pressures at the main points in the cycle")
+
+T4=T1/(r1)^(y-1);
+disp("T4=")
+disp(T4)
+disp("K")
+
+T3=T4;
+disp("T3=")
+disp(T3)
+disp("K")
+
+p2=p1/r2;
+disp("p2=")
+disp(p2/10^5)
+disp("bar")
+
+p3=p2/(r1)^y;
+disp("p3=")
+disp(p3/10^5)
+disp("bar")
+
+p4=p1/(r1)^y;
+disp("p4=")
+disp(p4/10^5)
+disp("bar")
+
+
+disp("(ii) Change in entropy =")
+dS=p1*V1/T1/10^3*log(r2);
+disp(dS)
+disp("kJ/K")
+
+
+disp("(iii) Mean thermal efficiency of the cycle")
+Qs=T1*(dS);
+Qr=T4*(dS);
+
+n=1-Qr/Qs;
+disp("n=")
+disp(n)
+
+
+disp("(iv) Mean effective pressure of the cycle =")
+pm=(Qs-Qr)/8/V1/100; //bar
+disp(pm)
+disp("bar")
+
+
+n=210; //cycles per minute
+disp("(v) Power of the engine =")
+P=(Qs-Qr)*n/60; //kW
+disp(P)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.30/30.sce b/551/CH13/EX13.30/30.sce new file mode 100755 index 000000000..f8823db0f --- /dev/null +++ b/551/CH13/EX13.30/30.sce @@ -0,0 +1,84 @@ +clc
+v=10:1:100;
+function p=f(v)
+ p=1/v^1.4;
+endfunction
+plot(v,f)
+
+v=[10 20]
+p=[f(10) f(10)]
+plot(v,p,'r')
+
+v=20:1:100;
+function p=fa(v)
+ p=2.6515/v^1.4;
+endfunction
+plot(v,fa,'g')
+
+v=[100 100]
+p=[f(100) fa(100)]
+plot(v,p,'--p')
+
+v=[15 15]
+p=[f(15) 0.040]
+plot(v,p,'--')
+
+v=[20 20]
+p=[f(20) 0.040]
+plot(v,p,'--r')
+
+xtitle("p-v diagram", "v", "p")
+legend("1-2b","2b-3", "3-4", "4-1", "2a-3a", "2-3")
+
+//The air-standard Otto, Dual and Diesel cycles are drawn on common p-v and T-s diagrams for the same maximum pressure and maximum temperature, for the purpose of comparison.
+// Otto 1-2-3-4-1
+// Dual 1-2a-3a-3-4-1
+// Diesel 1-2b-3-4-1
+
+
+xset('window', 1)
+
+s=10:1:50;
+function T=fb(s)
+ T=s^2
+endfunction
+plot(s,fb)
+
+s=10:1:50;
+function T=fc(s)
+ T=(s+30)^2
+endfunction
+plot(s,fc,'r')
+
+s=[12 12];
+T=[fb(12) fc(12)];
+plot(s,T,'--p')
+
+s=[45 45];
+T=[fb(45) fc(45)]
+plot(s,T,'m')
+
+s=10:1:27;
+T=5*(s)^2;
+plot(s,T,'g')
+
+s=10:1:20;
+T=7*s^2;
+plot(s,T,'--r')
+
+xtitle("T-s diagram", "s", "T")
+legend("1-4", "2b-3", "1-2b", "3-4", "2-3", "2a-3a")
+
+// The construction of cycles on T-s diagram proves that for the given conditions the heat rejected is same for all the three cycles (area under process line 4-1).
+// η=1-(Heat rejected)/(Heat supplied)=1-constant/Qs
+
+// The cycle with greater heat addition will be more efficient.
+// From the T-s diagram
+
+// Qs(diesel) = Area under 2b-3
+// Qs(dual) = Area under 2a-3a-3
+// Qs(otto) = Area under 2-3.
+
+// Qs(diesel) > Qs(dual) > Qs(otto)
+
+disp("Thus, ηdiesel > ηdual > ηotto")
\ No newline at end of file diff --git a/551/CH13/EX13.31/31.sce b/551/CH13/EX13.31/31.sce new file mode 100755 index 000000000..9fac4a29d --- /dev/null +++ b/551/CH13/EX13.31/31.sce @@ -0,0 +1,27 @@ +clc
+cp=0.92;
+cv=0.75;
+y=1.22; //y=cp/cv
+p1=1; //bar
+p2=p1;
+p3=4; //bar
+p4=16; //bar
+T2=300; //K
+
+T3=T2*(p3/p2)^((y-1)/y);
+T4=p4/p3*T3;
+T1=T4/(p4/p1)^((y-1)/y);
+
+disp("(i) Work done per kg of gas ")
+Q_supplied=cv*(T4-T3);
+Q_rejected=cp*(T1-T2);
+
+W=Q_supplied-Q_rejected;
+disp("W=")
+disp(W)
+disp("kJ/kg")
+
+
+disp("(ii) Efficiency of the cycle =")
+n=W/Q_supplied;
+disp(n)
\ No newline at end of file diff --git a/551/CH13/EX13.32/32.sce b/551/CH13/EX13.32/32.sce new file mode 100755 index 000000000..a2a9536c3 --- /dev/null +++ b/551/CH13/EX13.32/32.sce @@ -0,0 +1,25 @@ +clc
+p1=101.325; //kPa
+T1=300; //K
+rp=6;
+y=1.4;
+
+T2=T1*rp^((y-1)/y);
+
+//T3/T4=rp^((y-1)/y)
+//T4=T3/1.668
+
+//W_T=2.5*W_C
+
+T3=2.5*(T2-T1)/(1-1/1.668);
+disp("(i) Maximum temperature in the cycle =")
+disp(T3)
+disp("K")
+
+
+disp("(ii) Cycle efficiency")
+T4=T3/1.668;
+
+n_cycle=((T3-T4) - (T2-T1))/(T3-T2);
+disp(" Cycle efficiency =")
+disp(n_cycle)
\ No newline at end of file diff --git a/551/CH13/EX13.33/33.sce b/551/CH13/EX13.33/33.sce new file mode 100755 index 000000000..01a6ec8fa --- /dev/null +++ b/551/CH13/EX13.33/33.sce @@ -0,0 +1,40 @@ +clc
+p1=1; //bar
+p2=5; //bar
+T3=1000; //K
+cp=1.0425; //kJ/kg K
+cv=0.7662; //kJ/kg K
+y=cp/cv;
+
+disp("(i)Temperature entropy diagram")
+
+s=10:1:50;
+function T=fb(s)
+ T=s^2
+endfunction
+plot(s,fb,'--')
+
+s=10:1:50;
+function T=fc(s)
+ T=(s+30)^2
+endfunction
+plot(s,fc,'r')
+
+s=[12 12];
+T=[fb(12) fc(12)];
+plot(s,T,'m')
+
+s=[45 45];
+T=[fb(45) fc(45)]
+plot(s,T,'g')
+
+
+xtitle("T-s diagram", "s", "T")
+legend("p1=1 bar", "p2=5 bar", "1-2", "3-4")
+
+disp("(ii) Power required =")
+T4=T3*(p1/p2)^((y-1)/y);
+P=cp*(T3-T4);
+disp("P=")
+disp(P)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.34/34.sce b/551/CH13/EX13.34/34.sce new file mode 100755 index 000000000..68cc266ce --- /dev/null +++ b/551/CH13/EX13.34/34.sce @@ -0,0 +1,17 @@ +clc
+m=0.1; //kg/s
+p1=1; //bar
+T4=285; //K
+p2=4; //bar
+cp=1; //kJ/kg K
+y=1.4;
+
+T3=T4*(p2/p1)^((y-1)/y);
+disp("Temperature at turbine inlet =")
+disp(T3)
+disp("K")
+
+P=m*cp*(T3-T4);
+disp("Power developed =")
+disp(P)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.35/35.sce b/551/CH13/EX13.35/35.sce new file mode 100755 index 000000000..4777574cb --- /dev/null +++ b/551/CH13/EX13.35/35.sce @@ -0,0 +1,34 @@ +clc
+y=1.4;
+cp=1.005; //kJ/kg K
+p1=1; //bar
+T1=293; //K
+p2=3.5; //bar
+T3=873; //K
+rp=p2/p1;
+
+disp("(i) Efficiency of the cycle =")
+n_cycle=1-1/rp^((y-1)/y);
+disp(n_cycle)
+
+
+disp("(ii) Heat supplied to air =")
+T2=T1*(p2/p1)^((y-1)/y);
+Q1=cp*(T3-T2);
+disp(Q1)
+disp("kJ/kg")
+
+disp("(iii) Work available at the shaft =")
+W=n_cycle*Q1;
+disp(W)
+disp("kJ/kg")
+
+disp("(iv) Heat rejected in the cooler =")
+Q2=Q1-W;
+disp(Q2)
+disp("kJ/kg")
+
+disp("(v) Temperature of air leaving the turbine =")
+T4=T3/rp^((y-1)/y);
+disp(T4)
+disp("K")
\ No newline at end of file diff --git a/551/CH13/EX13.36/36.sce b/551/CH13/EX13.36/36.sce new file mode 100755 index 000000000..fa9d3e541 --- /dev/null +++ b/551/CH13/EX13.36/36.sce @@ -0,0 +1,21 @@ +clc
+T1=303; //K
+T3=1073; //K
+C=45000; //kJ/kg
+cp=1; //kJ/kg K
+y=1.4;
+
+T2=sqrt(T1*T3);
+T4=T2;
+
+//W_turbine-W_compressor=m_f*C*n=100;
+
+m_f=100/C/(1-(T4-T1)/(T3-T2));
+disp("m_f=")
+disp(m_f)
+disp("kg/s")
+
+m_a=(100-m_f*(T3-T4))/(T3-T4-T2+T1);
+disp("m_a=")
+disp(m_a)
+disp("kg/s")
\ No newline at end of file diff --git a/551/CH13/EX13.37/37.sce b/551/CH13/EX13.37/37.sce new file mode 100755 index 000000000..bfa324954 --- /dev/null +++ b/551/CH13/EX13.37/37.sce @@ -0,0 +1,44 @@ +clc
+T1=300; //K
+p1=1; //bar
+rp=6.25;
+T3=1073; //K
+n_comp=0.8;
+n_turbine=0.8;
+cp=1.005; //kJ/kg K
+y=1.4;
+
+T2=T1*(rp)^((y-1)/y);
+
+//Let T2'=T2a
+T2a=(T2-T1)/n_comp + T1;
+
+W_comp=cp*(T2a-T1);
+disp("Compressor work =")
+disp(W_comp)
+disp("kJ/kg")
+
+T4=T3/rp^((y-1)/y);
+T4a=T3-n_turbine*(T3-T4);
+
+W_turbine=cp*(T3-T4a);
+disp("Turbine work =")
+disp(W_turbine)
+disp("kJ/kg")
+
+Q_s=cp*(T3-T2a);
+disp("Heat supplied =")
+disp(Q_s)
+disp("kJ/kg")
+
+W_net=W_turbine - W_comp;
+
+n_cycle=W_net/Q_s*100;
+disp("n_cycle")
+disp(n_cycle)
+disp("%")
+
+t4a=T4a-273;
+disp("Turbine exhaust temperature =")
+disp(t4a)
+disp("0C")
\ No newline at end of file diff --git a/551/CH13/EX13.38/38.sce b/551/CH13/EX13.38/38.sce new file mode 100755 index 000000000..761e53e8b --- /dev/null +++ b/551/CH13/EX13.38/38.sce @@ -0,0 +1,19 @@ +clc
+n_turbine=0.85;
+n_compressor=0.80;
+T3=1148; //K
+T1=300; //K
+cp=1; //kJ/kg K
+y=1.4;
+p1=1; //bar
+p2=4; //bar
+C=42000; //kJ/kg K
+n_cc=0.90;
+
+T2=T1*(p2/p1)^((y-1)/y);
+
+T2a=(T2-T1)/n_compressor + T1;
+
+ratio=0.9*C/cp/(T3-T2a) - 1; //ratio=ma/mf
+disp("A/F ratio =")
+disp(ratio)
\ No newline at end of file diff --git a/551/CH13/EX13.39/39.sce b/551/CH13/EX13.39/39.sce new file mode 100755 index 000000000..95ecf0c81 --- /dev/null +++ b/551/CH13/EX13.39/39.sce @@ -0,0 +1,30 @@ +clc
+cp=1.005; //kJ/kg K
+y1=1.4;
+y2=1.333;
+p1=1; //bar
+p4=p1;
+T1=300; //K
+p2=6.2; //bar
+p3=p2;
+n_compressor=0.88;
+C=44186; //kJ/kg
+ratio=0.017; //Fuel-air ratio; kJ/kg of air
+n_turbine=0.9; //
+cpg=1.147;
+
+T2=T1*(p2/p1)^((y1-1)/y1);
+T2a=(T2-T1)/n_compressor + T1; //T2'
+
+T3=ratio*C/(1+ratio)/cp + T2a;
+T4=T3*(p4/p3)^((y2-1)/y2);
+T4a=T3-n_turbine*(T3-T4);
+W_compressor=cp*(T2a-T1);
+W_turbine=cpg*(T3-T4a);
+W_net=W_turbine-W_compressor;
+Qs=ratio*C;
+
+n_th=W_net/Qs*100;
+disp("Thermal efficiency =")
+disp(n_th)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.4/4.sce b/551/CH13/EX13.4/4.sce new file mode 100755 index 000000000..9ca5049cd --- /dev/null +++ b/551/CH13/EX13.4/4.sce @@ -0,0 +1,21 @@ +clc
+
+// First case
+//(T1-T2)/T1=1/6
+//T1=1.2*T2
+
+
+// Second case
+//(T1-(T2-(70+273)))/T3=1/3
+
+T2=1029/0.6;
+T1=1.2*T2;
+
+disp("Temperature of the source =")
+disp(T1)
+disp("K")
+
+
+disp("Temperature of the sink=")
+disp(T2)
+disp("K")
\ No newline at end of file diff --git a/551/CH13/EX13.40/40.sce b/551/CH13/EX13.40/40.sce new file mode 100755 index 000000000..564dc84c9 --- /dev/null +++ b/551/CH13/EX13.40/40.sce @@ -0,0 +1,36 @@ +clc
+cp=1; //kJ/kg K
+y=1.4;
+C=41800; //kJ/kg
+p1=1; //bar
+T1=293; //K
+p2=4; //bar
+p4=p1;
+p3=p2;
+n_compressor=0.80;
+n_turbine=0.85;
+ratio=90; //Air-Fuel ratio
+m_a=3; //kg/s
+
+disp("(i)Power developed ")
+T2=T1*(p2/p1)^((y-1)/y);
+T2a=(T2-T1)/n_compressor + T1;
+T3=C/(1+ratio)/cp + T2a;
+T4=T3*(p4/p3)^((y-1)/y);
+T4a=T3-n_turbine*(T3-T4);
+
+W_turbine=(ratio+1)/ratio*cp*(T3-T4a);
+W_compressor=cp*(T2a-T1);
+W_net=W_turbine-W_compressor;
+Qs=1/ratio*C;
+
+P=m_a*W_net;
+disp("Power=")
+disp(P)
+disp("kW/kg of air")
+
+
+disp("(ii) Thermal efficiency of cycle =")
+n_thermal=W_net/Qs;
+disp(n_thermal)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.41/41.sce b/551/CH13/EX13.41/41.sce new file mode 100755 index 000000000..84555c48d --- /dev/null +++ b/551/CH13/EX13.41/41.sce @@ -0,0 +1,25 @@ +clc
+T1=288; //K
+T3=883; //K
+rp=6; //rp=p2/p1
+n_compressor=0.80;
+n_turbine=0.82;
+m_a=16; //kg/s
+cp1=1.005; //kJ/kg K, For compression process
+y1=1.4; // For compression process
+cp2=1.11; //kJ/kg K
+y2=1.333;
+
+T2=T1*(rp)^((y1-1)/y1);
+T2a=(T2-T1)/n_compressor + T1;
+T4=T3/rp^((y2-1)/y2);
+T4a=T3-n_turbine*(T3-T4);
+
+W_compressor=cp1*(T2a-T1);
+W_turbine=cp2*(T3-T4a);
+W_net=W_turbine-W_compressor;
+
+Power=m_a*W_net;
+disp("Power =")
+disp(Power)
+disp("kW")
\ No newline at end of file diff --git a/551/CH13/EX13.42/42.sce b/551/CH13/EX13.42/42.sce new file mode 100755 index 000000000..ac605c087 --- /dev/null +++ b/551/CH13/EX13.42/42.sce @@ -0,0 +1,17 @@ +clc
+cp=1.11;
+T3=883; //K
+T2a=529; //K
+W_turbine=290.4; //kJ/kg
+W_net=48.2; //kJ/kg
+
+Qs=cp*(T3-T2a);
+
+n_thermal=W_net/Qs*100;
+disp("Thermal efficiency =")
+disp(n_thermal)
+disp("%")
+
+W_ratio=W_net/W_turbine; //Work ratio=net work output/Gross work output
+disp("Work ratio =")
+disp(W_ratio)
\ No newline at end of file diff --git a/551/CH13/EX13.43/43.sce b/551/CH13/EX13.43/43.sce new file mode 100755 index 000000000..144665e27 --- /dev/null +++ b/551/CH13/EX13.43/43.sce @@ -0,0 +1,40 @@ +clc
+p1=1; //bar
+p2=5; //bar
+p3=4.9; //bar
+p4=1; //bar
+T1=293; //K
+T3=953; //K
+n_compressor=0.85;
+n_turbine=0.80;
+n_combustion=0.85;
+y=1.4;
+cp=1.024; //kJ/kg K
+P=1065; //kW
+
+disp("(i) The quantity of air circulation")
+T2=T1*(p2/p1)^((y-1)/y);
+T2a=(T2-T1)/n_compressor + T1;
+T4=T3*(p4/p3)^((y-1)/y);
+T4a=T3-n_turbine*(T3-T4);
+
+W_compressor=cp*(T2a-T1);
+W_turbine=cp*(T3-T4a);
+W_net=W_turbine-W_compressor;
+
+m_a=P/W_net;
+disp("m_a =")
+disp(m_a)
+disp("kg")
+
+
+disp("(ii) Heat supplied per kg of air circulation =")
+Qs=cp*(T3-T2a)/n_combustion;
+disp(Qs)
+disp("kJ/kg")
+
+
+disp("(iii) Thermal efficiency of the cycle =")
+n_thermal=W_net/Qs*100;
+disp(n_thermal)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.44/44.sce b/551/CH13/EX13.44/44.sce new file mode 100755 index 000000000..89a9f4fe8 --- /dev/null +++ b/551/CH13/EX13.44/44.sce @@ -0,0 +1,25 @@ +clc
+m_a=20; //kg/s
+T1=300; //K
+T3=1000; //K
+rp=4; //rp=p2/p1
+cp=1; //kJ/kg K
+y=1.4;
+
+T2=T1*(rp)^((y-1)/y);
+T4=T3-T2+T1;
+
+//p5/p4=(p5/p3)*(p3/p4)
+//let p3/p4=r1
+r1=(T3/T4)^(y/(y-1));
+
+//r2=p5/p4;
+r2=1/4*r1;
+P_ratio=1/r2; //Pressure ratio of low pressure turbine
+disp("Pressure ratio of low pressure turbine =")
+disp(P_ratio)
+
+T5=T4/(P_ratio)^((y-1)/y);
+disp("Temperature of the exhaust from the unit =")
+disp(T5)
+disp("K")
\ No newline at end of file diff --git a/551/CH13/EX13.45/45.sce b/551/CH13/EX13.45/45.sce new file mode 100755 index 000000000..f40ffe5bd --- /dev/null +++ b/551/CH13/EX13.45/45.sce @@ -0,0 +1,57 @@ +clc
+T1=288; //K
+p1=1.01; //bar
+rp=7;
+p2=rp*p1;
+p3=p2;
+p5=p1;
+n_compressor=0.82;
+n_turbine=0.85;
+n_turbine=0.85;
+T3=883; //K
+cpa=1.005;
+cpg=1.15;
+y1=1.4;
+y2=1.33;
+
+disp("(i) Pressure and temperature of the gases entering the power turbine =")
+
+T2=T1*rp^((y1-1)/y1);
+T2a=(T2-T1)/n_compressor + T1;
+
+W_compressor=cpa*(T2a-T1);
+
+T4a=(cpg*T3-W_compressor)/cpg;
+disp("Temperature of gases entering the power turbine =")
+disp(T4a)
+disp("K")
+
+T4=T3-(T3-T4a)/n_turbine;
+
+p4=p3/(T3/T4)^(y2/(y2-1));
+disp("Pressure of gases entering the power turbine =")
+disp(p4)
+disp("bar")
+
+
+disp("(ii) Net power developed per kg/s mass flow")
+T5=T4a/(p4/p5)^((y2-1)/y2);
+T5a=T4a-n_turbine*(T4a-T5);
+
+W_turbine=cpg*(T4a-T5a);
+disp(" Net power developed per kg/s mass flow =")
+disp(W_turbine)
+disp("kW")
+
+
+disp("(iii) Work ratio =")
+W_ratio=W_turbine/(W_turbine+W_compressor);
+disp(W_ratio)
+
+
+disp("(iv) Thermal efficiency of the unit")
+Qs=cpg*(T3-T2a);
+n_thermal=W_turbine/Qs*100;
+disp("n_thermal =")
+disp(n_thermal)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.46/46.sce b/551/CH13/EX13.46/46.sce new file mode 100755 index 000000000..2e064a6db --- /dev/null +++ b/551/CH13/EX13.46/46.sce @@ -0,0 +1,27 @@ +clc
+T1=288; //K
+rp=4; //rp=p2/p1=p3/p4
+n_compressor=0.82;
+e=0.78; //Effectiveness of the heat exchanger
+n_turbine=0.70;
+T3=873; //K
+y=1.4;
+R=0.287;
+
+T2=T1*(rp)^((y-1)/y);
+T2a=(T2-T1)/n_compressor + T1;
+T4=T3/rp^((y-1)/y);
+T4a=T3-n_turbine*(T3-T4);
+
+cp=R*y/(y-1);
+W_compressor=cp*(T2a-T1);
+W_turbine=cp*(T3-T4a);
+W_net=W_turbine-W_compressor;
+
+T5=e*(T4a-T2a) + T2a;
+Qs=cp*(T3-T5);
+
+n_cycle=W_net/Qs*100;
+disp("Efficiency =")
+disp(n_cycle)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.47/47.sce b/551/CH13/EX13.47/47.sce new file mode 100755 index 000000000..75b6f70a2 --- /dev/null +++ b/551/CH13/EX13.47/47.sce @@ -0,0 +1,50 @@ +clc
+
+//Simple cycle
+p2=4; //bar
+p1=1; //bar
+T1=293;
+n_compressor=0.8;
+n_turbine=0.85;
+ratio=90; //Air Fuel ratio
+C=41800; //kJ/kg
+cp=1.024;
+p4=1.01; //bar
+p3=3.9; //bar
+y=1.4;
+e=0.72; //thermal ratio
+
+T2=T1*(p2/p1)^((y-1)/y);
+T2a=(T2-T1)/n_compressor + T1;
+T3=C/cp/(ratio+1)+471;
+T4=T3*(p4/p3)^((y-1)/y);
+
+T4a=T3-n_turbine*(T3-T4);
+
+n_thermal1=((T3-T4a)-(T2a-T1))/(T3-T2a)*100;
+disp("Thermal efficiency of simple cycle=")
+disp(n_thermal1)
+disp("%")
+
+
+//Heat exchanger cycle
+
+T2a=471; // K (as for simple cycle)
+T3=919.5; // K (as for simple cycle)
+p3=4.04-0.14-0.05; //bar
+p4=1.01+0.05; //bar
+
+T4=T3*(p4/p3)^((y-1)/y);
+T4a=T3-n_turbine*(T3-T4);
+
+T5=e*(T4a-T2a) + T2a;
+
+n_thermal2=((T3-T4a) - (T2a-T1))/(T3-T5)*100;
+disp("Thermal efficiency of heat exchanger cycle =")
+disp(n_thermal2)
+disp("%")
+
+dn=n_thermal2-n_thermal1;
+disp("Increase in thermal efficiency =")
+disp(dn)
+disp("%")
\ No newline at end of file diff --git a/551/CH13/EX13.48/48.sce b/551/CH13/EX13.48/48.sce new file mode 100755 index 000000000..722ff5907 --- /dev/null +++ b/551/CH13/EX13.48/48.sce @@ -0,0 +1,50 @@ +clc +T1=293; //K +T6=898; //K +T8=T6; +n_c=0.8; //Efficiency of each compressor stage +n_t=0.85; //Efficiency of each turbine stage +n_mech=0.95; +e=0.8; +cpa=1.005; //kJ/kg K +cpg=1.15; //kJ/kg K +y1=1.4; +y2=1.333; + +disp("(i) Thermal efficiency") +T3=T1; + +// p2/p1=sqrt(9)=3 +T2=T1*(3)^((y1-1)/y1); +T2a=(T2-T1)/n_c + T1; +T4a=T2a; +W_c=cpa*(T2a-T1); //Work input per compressor stage +W_t=2*W_c/n_mech; //Work output of H.P. turbine +T7a=T6-W_t/cpg; +T7=T6-(T6-T7a)/n_t; + +// (p6/p7)=(T6/T7)^(y2/(y2-1))=4.82; +// p8/p9=9/4.82=1.86 +T9=T8/(1.86)^((y2-1)/y2); +T9a=T8-n_t*(T8-T9); + +W=cpg*(T8-T9a)*n_mech; //Net work output +T5=e*(T9a-T4a)+T4a; + +Q=cpg*(T6-T5)+cpg*(T8-T7a); //Heat supplied +n_thermal=W/Q*100; +disp("n_thermal =") +disp(n_thermal) +disp("%") + +disp("(ii) Work ratio") +Gross_work=W_t+W/n_mech; +W_ratio=W/Gross_work; +disp("Work ratio=") +disp(W_ratio) + + +disp("(iii) Mass flow rate =") +m=4500/W; +disp(m) +disp("kg/s")
\ No newline at end of file diff --git a/551/CH13/EX13.49/49.sce b/551/CH13/EX13.49/49.sce new file mode 100755 index 000000000..5acd314c1 --- /dev/null +++ b/551/CH13/EX13.49/49.sce @@ -0,0 +1,42 @@ +clc +T1=293; //K +T5=1023; //K +T7=T5; +p1=1.5; //bar +p2=6; //bar +n_c=0.82; +n_t=0.82; +e=0.70; +P=350; //kW +cp=1.005; //kJ/kg K +y=1.4; + +T3=T1; +px=sqrt(p1*p2); +T2=T1*(px/p1)^((y-1)/y); +T2a=T1+(T2-T1)/n_c; +T4a=T2a; +p5=p2; +T6=T5/(p5/px)^((y-1)/y); +T6a=T5-n_t*(T5-T6); +T8a=T6a; +Ta=T4a+e*(T8a-T4a); +W_net=2*cp*[(T5-T6a)-(T2a-T1)]; + +Q1=cp*(T5-T4a)+cp*(T7-T6a); //Without regenerator +Q2=cp*(T5-Ta)+cp*(T7-T6a); + +disp("n_thermal without regenerator =") +n1=W_net/Q1*100; +disp(n1) +disp("%") + +disp("n_thermal woth regenerator =") +n2=W_net/Q2*100; +disp(n2) +disp("%") + +disp("(iii) Mass of fluid circulated =") +m=P/W_net; +disp(m) +disp("kg/s")
\ No newline at end of file diff --git a/551/CH13/EX13.5/5.sce b/551/CH13/EX13.5/5.sce new file mode 100755 index 000000000..5f2622c9b --- /dev/null +++ b/551/CH13/EX13.5/5.sce @@ -0,0 +1,17 @@ +clc
+
+T1=1990; //K
+T2=850; //K
+Q=32.5/60; //kJ/s
+P=0.4; //kW
+
+n_carnot=(T1-T2)/T1;
+disp("most efficient engine is one that works on Carnot cycle")
+disp(n_carnot)
+
+n_th=P/Q;
+disp("n_thermal =")
+disp(n_th)
+
+disp("which is not feasible as no engine can be more efficient than that working on Carnot")
+disp("Hence claims of the inventor is not true.")
\ No newline at end of file diff --git a/551/CH13/EX13.7/7.sce b/551/CH13/EX13.7/7.sce new file mode 100755 index 000000000..9db6085ef --- /dev/null +++ b/551/CH13/EX13.7/7.sce @@ -0,0 +1,8 @@ +clc
+
+n=0.6;
+y=1.5;
+
+r=(1/(1-n))^(1/(y-1));
+disp("Compression ratio =")
+disp(r)
\ No newline at end of file diff --git a/551/CH13/EX13.8/8.sce b/551/CH13/EX13.8/8.sce new file mode 100755 index 000000000..cb0fb3984 --- /dev/null +++ b/551/CH13/EX13.8/8.sce @@ -0,0 +1,25 @@ +clc
+
+D=0.25; //m
+L=0.375; //m
+Vc=0.00263; //m^3
+p1=1; //bar
+T1=323; //K
+p3=25; //bar
+Vs=%pi/4*D^2*L;
+r=(Vs+Vc)/Vc;
+y=1.4;
+
+disp("(i) Air standard efficiency=")
+n_otto=1-1/(r^(y-1));
+disp(n_otto)
+
+
+disp("(ii) Mean effective pressure ")
+p2=p1*(r)^(y);
+r_p=p3/p2;
+
+p_m=p1*r*(r^(y-1) - 1)*(r_p - 1)/(y-1)/(r-1);
+disp("Mean effective pressure =")
+disp(p_m)
+disp("bar")
\ No newline at end of file diff --git a/551/CH13/EX13.9/9.sce b/551/CH13/EX13.9/9.sce new file mode 100755 index 000000000..39612f0f3 --- /dev/null +++ b/551/CH13/EX13.9/9.sce @@ -0,0 +1,50 @@ +clc
+cv=0.72; //kJ/kg K
+y=1.4;
+p1=1; //bar
+T1=300; //K
+Q=1500; //kJ/kg
+r=8;
+y=1.4;
+
+disp("(i) Pressures and temperatures at all points")
+T2=T1*(r)^(y-1);
+disp("T2=")
+disp(T2)
+disp("K")
+
+p2=p1*(r)^y;
+disp("p2=")
+disp(p2)
+disp("bar")
+
+T3=Q/cv + T2;
+disp("T3=")
+disp(T3)
+disp("K")
+
+p3=p2*T3/T2;
+disp("p3=")
+disp(p3)
+disp("bar")
+
+T4=T3/r^(y-1);
+disp("T4=")
+disp(T4)
+disp("K")
+
+p4=p3/r^(y);
+disp("p4=")
+disp(p4)
+disp("bar")
+
+
+disp("(ii) Specific work and thermal efficiency")
+SW=cv*[(T3-T2) - (T4-T1)];
+disp("Specific work =")
+disp(SW)
+disp("kJ/kg")
+
+n_th=1-1/r^(y-1);
+disp("Thermal efficiency =")
+disp(n_th)
\ No newline at end of file |