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//Fluid Systems - By - Shiv Kumar
//Chapter 11- Centrifugal Pumps
//Example 11.12
//To Determine (i)Manometric Efficiency (ii)Vane Angle at Inlet (iii)The Least Speed at which the pump commence to work.
clc
clear
//Given Data:-
Do=0.5; //Outer Diameter of the Impeller, m
N=600; //Speed, rpm
Q=8000; //Discharge, litres/min.
Hm=8.5; //Manometric Head, m
Di=0.25; //Inner Diameter of Impeller, m
beta_o=45; //Vane Angle at outlet, degrees
Af=0.06; //Area of Flow, m^2
//Data Used:-
g=9.81; //Acceleration due to gravity, m/s^2
//Computations:-
Q=Q/60000; //m^3/s
Vfo=Q/Af; //m/s
Vfi=Vfo;
ui=%pi*Di*N/60; //Tangential velocity of Impeller at Inlet,m/s
uo=%pi*Do*N/60; // Tangential velocity of Impeller at Outlet, m/s
Vwo=uo-Vfo/tand(beta_o); //m/s
//(i) Manometric Efficiency, eta_man
eta_man=g*Hm/(Vwo*uo)*100; //In Percentage
//(ii) Vane Angle at Inlet, beta_i
beta_i=atand(Vfi/ui); //degrees
//(iii) The Least Speed at which the pump commence to work, Nmin
Nmin=120*Vwo*Do*(eta_man/100)/(%pi*(Do^2-Di^2)); //rpm
//Results:-
printf(" (i) Manometric Efficiency, eta_man =%.2f Percent \n ",eta_man ) //The answer vary due to round off error
printf(" (ii) Vane Angle at Inlet, beta_i=%.2f Degrees \n ",beta_i ) //The answer vary due to round off error
printf(" (iii) The Least Speed at which the pump commence to work, Nmin=%.2f rpm \n",Nmin ) //The answer vary due to round off error
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