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+// scilab Code Exa 12.3 Calculation on a centrifugal compressor stage 
+
+funcprot(0)
+T01=306;  // Entry Temperature in Kelvin
+p01=1.05; //  Entry Pressure in bar
+dh=0.12; // hub diameter in m
+dt=0.24; // tip diameter in m
+m=8; //  in kg/s
+mu=0.92; // slip factor
+n_st=0.77; // stage efficiency
+gamma=1.4;
+N=17e3; // rotor Speed in RPM
+d_it=0.48; // Impeller tip diameter in m
+d1=0.5*(dt+dh); // Mean Blade ring diameter
+rm=d1/2;
+cp=1005; // Specific Heat at Constant Pressure in J/(kgK)
+A=%pi*((dt^2)-(dh^2))/4;
+R=287;
+n=86; // number of iterations
+ro01=(p01*1e5)/(R*T01);
+cx(1)=m/(ro01*A);
+for i=1:n
+    T1=T01-((cx(i)^2)/(2*cp));
+    p1=p01*((T1/T01)^(1/((gamma-1)/gamma)));
+ro1=(p1*1e5)/(R*T1);
+cx(i+1)=m/(ro1*A);
+if cx(i+1)==cx(i) then
+    disp("m/s",cx(i+1),"cx=")
+    disp(T1,"T1")
+disp(p1,"p1")
+disp(ro1,"ro1")
+end 
+end
+cx1=cx(i+1);
+u1m=%pi*d1*N/60;
+omega=u1m/rm;
+rh=dh/2;
+rt=dt/2;
+uh=omega*rh;
+ut=omega*rt;
+u2=d_it*u1m/d1;
+beta1h=atand(cx1/uh);
+beta1m=atand(cx1/u1m);
+beta1t=atand(cx1/ut);
+disp("(a) Without IGVs")
+disp("degree",beta1h,"air angle at hub section beta1h=")
+disp("degree",beta1m,"air angle at mean section beta1m=")
+disp("degree",beta1t,"air angle at tip section beta1t=")
+w1t=cx1/(sind(beta1t));
+a1=sqrt(gamma*R*T1);
+M1t=w1t/a1;
+disp(M1t,"the maximum Mach number at inducer blade entry M1t=")
+pr0=((1+(mu*n_st*(u2^2)/(cp*T01)))^(1/((gamma-1)/gamma)));
+disp(pr0,"total pressure ratio developed is")
+P=m*mu*(u2^2);
+disp ("kW",P/1000,"Power required to drive the compressor without IGVs is")
+
+// part(b) with IGVs
+alpha1h=beta1h;
+alpha1m=beta1m;
+alpha1t=beta1t;
+disp("(b)With IGVs")
+disp("degree",alpha1h,"air angle at hub section alpha1h=")
+disp("degree",alpha1m,"air angle at mean section alpha1m=")
+disp("degree",alpha1t,"air angle at tip section alpha1t=")
+c1t=cx1/(sind(alpha1t));
+T1t=T01-((c1t^2)/(2*cp));
+a1t=sqrt(gamma*R*T1t);
+Mw1t=cx1/a1t;
+disp(Mw1t,"the maximum Mach number at inducer blade entry Mw1t=")
+pr0_w=((1+(n_st*(mu*(u2^2)-(u1m^2))/(cp*T01)))^(1/((gamma-1)/gamma)));
+disp(pr0_w,"total pressure ratio developed is")
+P_w=m*(mu*(u2^2)-(u1m^2));
+disp ("kW",P_w/1000,"Power required to drive the compressor is")
+disp("Comment: here the solution is found out using programming, so this gives slightly small variation from tha answers given in hte book, but answers from the present solution are exact.")