# Chapter 4 : Fuel Air Cycles And Real Cycles¶

## Example 4.1 Page no : 100¶

In :
import math

#Input data
d = 20.					#Bore in cm
l = 38.					#Stroke in cm
Vc = 900.					#Clearance volume in c.c
p1 = 1.					#Pressure at the start of compression stroke in kg/cm**2
T1 = 90.+273					#Temperature at the start of compression stroke in K
x = 0.75					#Piston travelled 0.75 of the compression stroke
n = 1.32					#Compression curve index
wa = 0.0125					#Weight of air in kg

#Calculations
Vs = (3.14/4)*d**2*l					#Swept volume in c.c
V1 = (Vs+Vc)					#Volume in c.c
V2 = (1-x)*Vs+Vc					#Volume in c.c
p2 = p1*(V1/V2)**n					#Pressure in kg/cm**2
T2 = (T1*(p2/p1)*(V2/V1))					#Temperature in K
W = ((p1*V1-p2*V2)/(n-1))*10**-2					#Workdone in kg.m
dI = wa*0.17*(T2-T1)					#Change in internal energy in kcal
q = (dI+(W/427))					#Heat in kcal

#Output
print 'When the cylinder has travelled %3.2f of the compression stroke,  \
\nThe volume is %3.0f c.c  \
\nThe pressure is %3.2f kg/cm**2  \
\nTemperature is %3.0f K  \
\nThe workdone on the gas is %3.2f kg.m  \
\nChange in internal energy between the two points is %3.3f kcal'%(x,V2,p2,T2,W,dI)

When the cylinder has travelled 0.75 of the compression stroke,
The volume is 3883 c.c
The pressure is 4.84 kg/cm**2
Temperature is 532 K
The workdone on the gas is -186.85 kg.m
Change in internal energy between the two points is 0.359 kcal