Week 6 - Data analysis

Aim: To write a python programme to perform data analysis of engine trials

Objectives:

1. To write python programme to visualize data according to the user input
2. To perform calculations such as
3. Area under P-V diagram
4. Power output of engine
5. Specific fuel consumption

Solution procedure:

import matplotlib.pyplot as plt
import numpy as np
from numpy import trapz
# To check file 
fname = input("Enter the filename:  ")

if fname == 'engine_data.out':
	print('file is valid')

else:

	print('file is invalid')

	exit()
# to check the compatability 
def compatibility_check(a):

	if 'CONVERGE' not in a:

		print('please provide converge output file to process')

		exit()

	else:

		print('compatibility check is successful')

		pass

FILE = []


# to read the file and split the line 
for line in open(fname):

	if '#' in line:

		FILE.append(line.split())

compatibility_check(FILE[0])

noc = len(FILE[1])
head = len(FILE[2])
col_no = []
col_val = []
col_units = []

z = FILE[1].index('column')
for i in range(z,noc-1):

	col_no.append(i)

for j in FILE[2]:

	if j is not '#':

		col_val.append(j)

for k in FILE[3]:

	if k is not '#':

		col_units.append(k)

print('data available are:')

for a in range(0,len(col_no)):

	print(col_no[a],col_val[a],col_units[a])

xaxis = int(input('Enter xaxis column no:'))-1
yaxis = int(input('Enter yaxis column no:'))-1

x = []
y = []

for line in open(fname):

	if '#' not in line:

		x.append(float(line.split()[xaxis]))
		y.append(float(line.split()[yaxis]))

plt.plot(x,y,linewidth=1.5)
plt.xlabel(col_val[xaxis])
plt.ylabel(col_val[yaxis])
plt.show()

pressure = []
vol = []

for line in open(fname):
	if '#' not in line:

		pressure.append(float(line.split()[1]))
		vol.append(float(line.split()[7]))

Pressure = 1e6*np.array(pressure)
Volume = np.array(vol)
area = np.trapz(Pressure,Volume)
print('workdone =',area, 'joules')
cyclepersec = 750/60
power = area*(cyclepersec/1000)
print('power=',power,'kw')
mass_flow = 20e-6
sfc = mass_flow*3600/power
print('specific fuel consumption =',sfc,'g/kwh')

Conclusion:

Crank angle VS Pressure diagram plotted and following parameters calculated

Work-done=500.5866 joules

Power=6.257 Kw

Specific fuel consumption =0.01150 g/Kwh