1 files changed, 56 insertions, 0 deletions
diff --git a/3720/CH14/EX14.3/Ex14_3.sce b/3720/CH14/EX14.3/Ex14_3.sce
new file mode 100644
index 000000000..587ff118c
--- /dev/null
+++ b/3720/CH14/EX14.3/Ex14_3.sce
@@ -0,0 +1,56 @@
+//Example 14-3
+clc;clear;
+// Given values
+P_atm=101.3*1000; // Pa
+g=9.81;// m/s^2
+alpha=1.05;
+eps=0.02*0.0254;//Roughness in m
+D=4*0.0254;// in 'm' converted from 'in'
+L=10.5*0.3048;//in 'm' converted from 'ft'
+gradz=1.219;// grad z=(z_1-z_2) in m
+
+// Calculation
+A=((%pi*D^2)/4);//Area in m^2
+v=300:10:700;//Volume flow rate in gpm
+T=[25 60];//Temperature matrix
+for j=1:1:length(T)
+    //Water properties at T = 25°C and 60°C respectively
+    if T(j)==25 then
+        rho=997.0;// kg/m^3
+        nu=8.91*10^-4;// Kinematic viscosity in kg/m.s 
+        mu=nu/rho;
+        P_v=3.169*1000;// Pa
+    else
+        rho=983.3;// kg/m^3
+        nu=4.67*10^-4;// Kinematic viscosity in kg/m.s 
+        mu=nu/rho;
+        P_v=19.94*1000;// Pa
+         
+    end
+
+for i=1:1:length(v);
+    
+    v_(i)=(6.309*10^-5)*v(i); //Volume flow rate in m3^s converted from gpm
+    V(i)=v_(i)/A;//Velocity in m/s 
+    Re=(4*v_(i))/(mu*%pi*D);//Reynolds number
+            
+    function [X]=fric(f)
+    X=-2.0*log10(((eps)/(3.7*D))+((2.51)/(Re*sqrt(f))))-1/sqrt(f); //Friction factor as a implicit function of Re using Colebrook equation
+    endfunction
+
+    f=0.00001; //Initial guess to solve X
+    fr=fsolve(f,fric);//Calculating friction factor
+       
+    sigmaK_l=0.5+(3*0.3)+6.0;// Minor losses
+    H_l=((fr*L)/D+sigmaK_l)*(V(i)^2/(2*g));//The required net head of the fan at the minimum flow rate
+    
+    NPSH(j,i)=((P_atm-P_v)/(rho*g))+(gradz)-(H_l)-((alpha-1)*(V(i)^2)/(2*g));
+end
+end
+F=[300 400 500 600 680];//Flow rate in gpm
+N=[3.8 4.44 5.06 6.13 7.0];//minimum NPSH required approximately taken from Fig.14-21
+plot(v',NPSH'*3.28,'r',F,N,'-o');
+xlabel('v,gpm');
+ylabel('NPSH,ft');
+legend('Available NPSH, 25°C','Available NPSH, 60°C','Required NPSH');
+printf('\nCavitation occurs at flow rates above approximately 600 gpm. \nThe maximum volume flow rate without cavitation decreases with temperature.')