wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

An IC engine is operating on the cycle shown below. The cycle takes in air at 1 bar and 300 K. The air is compressed isothermally and then heated at constant volume so that the pressure rises to 15 bar and temperature to 700 K. The air expands isothermally to its initial volume and rejects the cycle. What is the mean effective pressure



A
3.91 bar
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
3.21 bar
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2.94 bar
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
3.48 bar
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 2.94 bar

Given: P1=1 bar,T1=T2=300 K

P3=15 bar,T3=700 K

Compression ratio,V1V2=V1V3=V4V3=r

Net work done=WexpansionWcompression

=RT3logerRT1loger

=R(T3T1)loger

Assume 1 kg of air at the beginning of compression process.

v1=RT1P1=287×300105=0.861 m3/kg

v2=v3=RT3P3=287×70015×105=0.134 m3/kg

r=v1v2=6.425

Stroke volume=v1v2=0.727 m3/kg

W=R(T3T1)loger=287×(700300)loge6.425

=213.55 kJ/kg of air

Mean effective pressure=Work doneStroke volume=213.550.727=2.94 bar


flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Second Law of Thermodynamics
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon