# Chapter5 : Introduction to Convection¶

### Example 5.1 Page NO. 248¶

In [4]:
Cp=871
Gamma=1.3

Cv=Cp/Gamma
dT=20
m=5
Qp=m*Cp*dT
Qv=m*Cv*dT

print" The heat required at constant pressure is ",Qp/1000,"kj"
print"The heat required at constant volume is ",Qv/1000,"kj"

 The heat required at constant pressure is  87 kj
The heat required at constant volume is  67.0 kj


### Example 5.2 Page NO.250¶

In [1]:
T1_Fr=-50
T2_Fr=-40
rou1_Fr=1.546*1000
rou2_Fr=1.518*1000

beta_Fr=-(rou1_Fr-rou2_Fr)/(rou1_Fr*(T1_Fr-T2_Fr))
beta_acc_Fr=2.63e-3 # the accurate value of volumetric thermal expansion coefficient for Freon-12
error_Fr=(beta_acc_Fr-beta_Fr)*100/beta_acc_Fr
T1_He=366
T2_He=477
rou1_He=0.13280
rou2_He=0.10204
beta_He=-(rou1_He-rou2_He)/(rou1_He*(T1_He-T2_He))

print"The volumetric thermal expansion coefficient calculated for Freon-12 is ",round(beta_Fr,6),"1/K"
print"The error introduced in the case of Freon-12 is  percent",round(error_Fr,0),"percent"
print"The volumetric thermal expansion coefficient calculated for Freon-12 is ",round(beta_He,6),"1/K"

The volumetric thermal expansion coefficient calculated for Freon-12 is  0.001811 1/K
The error introduced in the case of Freon-12 is  percent 31.0 percent
The volumetric thermal expansion coefficient calculated for Freon-12 is  0.002087 1/K

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