1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
//Fluid Systems - By - Shiv Kumar
//Chapter 12- Reciprocating Pumps
//Example 12.12
//To Find the Maximum Speed at which the Pump may run without seperation.
clc
clear
//Given Data:-
D=10; //Plunger Diameter, cm
L=20; //Stroke Length, cm
H_s=4; //Suction Head, m
H_d=14; //Delivery Head, m
d_s=4; //Diameter of Suction Pipe, cm
l_s=6; //Length of Suction Pipe, m
d_d=3; //Diameter of Delivery Pipe, cm
l_d=18; //Length of Delivery Pipe, m
p=7.85; //Pressure (below atm.) for seperation, N/cm^2
H_a=10.3; //Atmospheric Pressure Head, m of water
//Data Used:-
g=9.81; //Acceleration due to gravity, m/s^2
rho=1000; //Density of water, kg/m^3
//Computations:-
d_s=d_s/100; //m
d_d=d_d/100; //m
D=D/100; //m
L=L/100; //m
a_s=(%pi/4)*d_s^2; //m^2
a_d=(%pi/4)*d_d^2; //m^2
A=(%pi/4)*D^2; //m^2
r=L/2; //m
H_sp=p*100^2/(rho*g); //Pressure Head of water for seperation, m (below atmosphere) (Value given in textbook is wrong due to incorrect value of p is used)
H_abs=H_a-H_sp; //Absolute Pressure Head of water for seperation, m
H_as_by_omega2=(l_s/g)*(A/a_s)*r; //H_as/omega^2
omega=sqrt((H_sp-H_s)/H_as_by_omega2); //rad/s
N_s=omega*60/(2*%pi); //rpm
H_ad_by_omega2=(l_d/g)*(A/a_d)*r; //H_as/omega^2
omega=sqrt((H_sp+H_d)/H_ad_by_omega2); //rad/s
N_d=omega*60/(2*%pi); //rpm
//Selecting maximum speed,
if N_s>N_d then
N=N_s;
else
N=N_d;
//Result:-
printf("Hence, The Maximum Speed at which Pump should be Run is %.2f rpm\n",N) //The answer vary due to round off error
|
