# Chapter3-The Principles Governing Fluids in Motion¶

## Ex2-pg105¶

In [1]:
import math
#calculate Overall efficiency of the pump
u_A=1.35; ## m/s
d_A=0.225; ## m
d_B=0.150; ## m
d_C=0.150; ## m
d=5.6; ##m
friction=2.5; ## kW
power_req=12.7; ## kW

rho=1000.; ## kg/m^3
rho_m=13560.; ## kg/m^3

g=9.81; ## m/s^2

pC=35000.; ## Pa
pA=rho_m*g*(-d_B);

Area_A=math.pi*d_A**2/4;
Area_B=math.pi*d_B**2/4;
Area_C=math.pi*d_C**2/4;

u_B=u_A*(Area_A/Area_B);
u_C=u_A*(Area_A/Area_C);

print'%s %.1f %s'%("Overall efficiency of the pump =",Efficiency," %")

Overall efficiency of the pump = 67.7  %


## Ex3-pg119¶

In [2]:
import math
#calculate Rate of discharge
d_jet = 0.0086; ## m
d_orifice = 0.011; ## m
x = 2.; ## m
y = 0.6; ## m
h = 1.75; ## m
g = 9.81; ## m/s^2

A2 = math.pi/4.*d_orifice**2;

Cc = (d_jet/d_orifice)**2.; ## Coefficient of Contraction

Cv = x/2./math.sqrt(y*h); ## Coefficient of velocity

Cd = Cv*Cc; ## Coefficient of Discharge

Q = Cd*A2*math.sqrt(2.*g*h);

print'%s %.4f %s'%("Rate of discharge =",Q,"m^3/s ")

Rate of discharge = 0.0003 m^3/s


## Ex4-pg122¶

In [3]:
import math
#calculate Flow rate
Cd=0.97;
d1=0.28; ## m
d2=0.14; ## m

g=9.81; ## m/s^2
d=0.05; ## difference in mercury level in metre
rho=1000.; ## kg/m^3
rho_m=13600.; ## kg/m^3

A1=math.pi/4.*d1**2.;
A2=math.pi/4.*d2**2.;

p_diff=(rho_m-rho)*g*d;
h=p_diff/rho/g;

Q=Cd*A1*((2.*g*h)/((A1/A2)**2-1.))**(1./2.);

print'%s %.4f %s'%("Flow rate =",Q,"m^3/s ")

Flow rate = 0.0542 m^3/s


## Ex5-pg125¶

In [4]:
import math
#calculate Mass flow rate
Cd=0.62;
g=9.81; ## m/s^2
d=0.1; ## m
d0=0.06; ## m
d1=0.12; ## m

rho=1000.; ## kg/m^3
rho_m=13600.; ## kg/m^3
rho_f=0.86*10**3; ##kg/m^3

A0=math.pi/4.*d0**2.;
A1=math.pi/4.*d1**2.;

p_diff=(rho_m-rho_f)*g*d;

h=p_diff/rho_f/g;

Q=Cd*A0*((2.*g*h)/(1.-(A0/A1)**2))**(1./2.);

m=rho_f*Q;

print'%s %.2f %s'%("Mass flow rate =",m,"kg/s ")

Mass flow rate = 8.39 kg/s


## Ex6-pg130¶

In [6]:
import math
Cd=0.61;
#calculate Rate of discharge
g=9.81; ## m/s^2
b=0.6; ## m
H=0.155; ## mQ
A=0.26; ## m^2
u1=0.254; ## m/s

Q=2./3.*Cd*math.sqrt(2.*g*b*(H)**3/2);

velo=Q/A;

H1=H+u1**2/(2.*g);

Q1=2./3.*Cd*math.sqrt(2*g*b*(H1)**3/2);

print'%s %.3f %s'%("Discharge =",Q1,"m^3/s")

Discharge = 0.062 m^3/s