# CHAPTER 15 - Engine Cooling¶

## EXAMPLE 15.1 PAGE 499¶

In [1]:
from __future__ import division
# Initialisation of Variables
BP=90#.................#Brake Power in kW
deltw=27#.................#Raise in temperature of water
etaP=0.25#...................#Efficiency of petrol engine
Pec=32#......................#Percentage of energy going to coolant in petrol engine
Dec=28#......................#Percentage of energy going to coolant in diesel engine
cp=4.187#..........#specific heat of water at constant pressure
#Calculations
hsP = BP/etaP#............#Heat supplied in kW or kJ/s
ecP=hsP*(Pec/100)#.............#Energy going to cooling water in kg/s
mwP=ecP/(cp*deltw)#.............#Mass of cooling water required
hsD = BP/etaD#............#Heat supplied in kW or kJ/s
ecD=hsD*(Dec/100)#.............#Energy going to cooling water in kg/s
mwD=ecD/(cp*deltw)#.............#Mass of cooling water required
print "The mass of cooling water required = %0.2f kg/h for petrol engine "%(mwP*3600)
print "The mass of cooling water required = %0.2f kg/h for diesel engine "%(mwD*3600)

The mass of cooling water required = 3668.50 kg/h for petrol engine
The mass of cooling water required = 2674.95 kg/h for diesel engine