In [3]:

```
import math
#Input data
d = 11.25 #Bore in cm
l = 15. #Stroke in cm
r = 7. #Compression ratio
N = 1800. #Speed in r.p.m
a = 4.5 #Air supply in kg/min
Ta = 72.+273 #Temperature of air in K
af = 14.3 #Air fuel ratio
ep = 1. #Exhaust pressure in kg/cm**2
R = 29.27 #Characteristic gas constant in kg.m/kg.degree C
#Calculations
Vc = ((r/(r-1))*(3.14/4)*(d/100)**2*(l/100)) #Swept volume in m**3
Wa = (Vc*N*ep*10**4)/(R*Ta) #Ideal air capacity in kg/min
sr = (a/Wa) #Scavenging ratio
sn = (1-math.exp(-sr)) #Scavenging efficiency
nt = (sn/sr) #Trapping efficiency
#Output
print 'a) Ideal air capacity is %3.2f kg/min \
\nb) Scavenging ratio is %3.2f \
\nc) Scavenging efficiency is %3.3f \
\nd) Trapping efficiency is %3.2f'%(Wa,sr,sn,nt)
```