# Chapter1-Fundamental concepts¶

## Ex1-pg18¶

In [1]:
import math
#calculate denisty of air and its mass
p=2.*10**5; ## Pa
T=300.; ## K
R=287.; ## J/(kg.K)
V=3.; ## m^3

rho=p/(R*T);
print'%s %.2f %s'%('The density of air =',rho,'kg/m^3')
m=rho*V;
print'%s %.2f %s'%('Its mass =',m,'m^3')

The density of air = 2.32 kg/m^3
Its mass = 6.97 m^3


## Ex2-pg19¶

In [3]:
import math
#calculate gas constant Co ,Co2 ,No,N2o
M_C=12.;
M_N=14.;
M_O=16.;
R=8314.; ## J/(kg.K)

M_CO=M_C+M_O;
R_CO=R/M_CO;

M_CO2=M_C+2.*M_O;
R_CO2=R/M_CO2;

M_NO=M_N+M_O;
R_NO=R/M_NO;

M_N2O=2.*M_N+M_O;
R_N2O=R/M_N2O;

print'%s %.1f %s'%('Gas constant for CO =',R_CO,'J/(kg.K)')
print'%s %.1f %s'%('Gas constant for CO2 =',R_CO2,'J/(kg.K)')
print'%s %.1f %s'%("Gas constant for NO =",R_NO,"J/(kg.K)")
print'%s %.1f %s'%("Gas constant for N2O =",R_N2O,"J/(kg.K)")

Gas constant for CO = 296.9 J/(kg.K)
Gas constant for CO2 = 189.0 J/(kg.K)
Gas constant for NO = 277.1 J/(kg.K)
Gas constant for N2O = 189.0 J/(kg.K)


## Ex3-pg36¶

In [4]:
import math
#calculate reynodls number and prove the
d=0.004; ## m
rho=1000; ## kg/m^3
v=3; ## m/s
meu=10**(-3); ## khm(m.s)

Re=rho*v*d/meu;
print'%s %.f %s'%("Reynolds number =",Re,"")

print("The Reynolds number is well in excess of 4000, so the flow is turbulent.")

Reynolds number = 12000
The Reynolds number is well in excess of 4000, so the flow is turbulent.