//Fluid Systems- By Shiv Kumar //Chapter 5- Francis Turbine //Example 5.5 //To Determine (a) Guide Blade Angle (b)Runner Vane Angles at Inlet and Outlet (c) Diameter of Runner at Inlet and Outlet (d) Width of Wheel at Inlet. clc clear //Given Data:- H=70; //Net Head, m N=600; //Speed, rpm P=367.875; //Shaft Power, kW eta_o=85/100; //Overall Efficiency eta_H=95/100; //Hydraulic Efficiency Kf=0.25; //Flow Ratio bo_by_Do=0.1; //Breadth Ratio t_per=10; //Percentage of Circumferential Area occupied by the Thickness of Vanes Kt=1-t_per/100; //Vane Thickness Factor //As Outer Diameter= 2 times the Inner Diameter, Do_by_Di=2; //Do/Di //Data Required:- rho=1000; //Density of Water, Kg/m^3 g=9.81; //Acceleration due to gravity, m/s^2 //Computations:- Vfi=Kf*sqrt(2*g*H); //m/s Vfo=Vfi; Q=P*1000/(rho*g*H*eta_o); //m^3/s Do=sqrt(Q/(Kt*%pi*bo_by_Do*Vfi)); //m Di=Do/Do_by_Di; //m bo=Do*bo_by_Do*1000; //mm bi=Do*bo/Di; //mm ui=%pi*Do*N/60; //m/s uo=%pi*Di*N/60; //m/s Vwi=eta_H*g*H/ui; //m/s //(a)Guide Vane Angle, alpha_i alpha_i=atand(Vfi/Vwi); //degrees // (b)Runner Vane Angles at Inlet and Outlet, beta_i,beta_o beta_i=atand(Vfi/(Vwi-ui)); //Runner Vane Angle at Inlet, degrees beta_o=atand(Vfo/uo); //Runner Vane Angle at Outlet, degrees //(c)Diameter of Runner at Inlet ant Outlet, Do and Di . //Calculated Above // (d) Width of Wheel at Inlet, bi. //Calculated Above //Results:- printf(" (a)Guide Vane Angle, alpha_i=%.2f Degrees\n ",alpha_i) //The Answer Vary due to Round off Error printf(" (b)Runner Vane Angles at Inlet and Outlet are:- \n beta_i=%.2f Degrees , beta_o =%.2f Degrees \n",beta_i,beta_o) //The Answer Vary due to Round off Error printf(" (c)Diameter of Runner at Inlet and Outlet are: \n Do=%.4f m Di=%.4f m \n",Do,Di) //The Answer(Do) Vary due to Round off Error printf(" (d) Width of Wheel at Inlet, bo=%.2f mm\n",bo ) //The Answer Vary due to Round off Error