How Does Torque Relate to Heat Engines and the Second Law of Thermodynamics?

Click For Summary
SUMMARY

This discussion focuses on the relationship between torque, heat engines, and the Second Law of Thermodynamics, specifically in the context of a multicylinder gasoline engine operating at 2500 rev/min. The engine takes in 7.89E3 J and exhausts 4.58E3 J per crankshaft revolution. Key calculations include fuel consumption based on a heat of combustion of 4.03E7 J/L, mechanical power output in horsepower, torque exerted by the crankshaft, and power transfer requirements for the exhaust and cooling systems. The participant successfully resolved the queries regarding torque and power transfer after initial confusion.

PREREQUISITES
  • Understanding of heat engines and thermodynamic principles
  • Familiarity with torque calculations in mechanical systems
  • Knowledge of power output measurements in horsepower
  • Basic concepts of energy transfer and combustion efficiency
NEXT STEPS
  • Calculate torque using the formula: Torque = Power / Angular Velocity
  • Explore the relationship between mechanical power and thermal efficiency in engines
  • Investigate the role of exhaust systems in heat engine performance
  • Learn about the implications of the Second Law of Thermodynamics on engine efficiency
USEFUL FOR

Engineers, physics students, and automotive professionals interested in the mechanics of heat engines and thermodynamic efficiency.

bruisika
Messages
2
Reaction score
0
we are learning about heat engines and the 2nd law of thermodynamics...and i don't know how to relate torque to these concepts...
the question is...
a multicylinder gasoline engine in an airplane, operating at 2500rev/min, takes in energy at 7.89E3 J and exhausts 4.58E3 J for each revolution of the crankshaft.
a) how many liters of fuel does it consume in 1 hr of operation if the heat of combustion is 4.03E7 J/L
b) what is the mechanical power output of the engine? ignore friction and express the answer in horsepower
c) what is the torque exerted by the crankshaft on the load
d) what power must the exhaust and cooling system transfer out of the engine?

i know how to do A and B, but i don't know where to start for C and D... can anyone help? THanks
Jenna
 
Physics news on Phys.org
figured it out

just kidding i figured it out..
 

Similar threads

How to Find the Number of Liters of Gas Used in a Gasoline Engine
  • · Replies 3 ·
Replies
3
Views
2K
Temperature in a Carnot heat engine
  • · Replies 2 ·
Replies
2
Views
3K
I calculating the heat exhausted from an engine.
  • · Replies 1 ·
Replies
1
Views
4K
How Efficient Can a Radiative Heat Engine Be for a Moon Base?
  • · Replies 1 ·
Replies
1
Views
2K
Thermodynamics: adiabatic processes
  • · Replies 4 ·
Replies
4
Views
2K
Can a thermodynamic heat engine include all these processes?
  • · Replies 2 ·
Replies
2
Views
2K
Calculating work done by a Carnot engine
  • · Replies 14 ·
Replies
14
Views
9K
How does the rise in temperature of fuse wire depend upon its radius?
  • · Replies 12 ·
Replies
12
Views
2K
Carnot Heat Engine, thermodynamics
  • · Replies 3 ·
Replies
3
Views
8K
How to calculate the efficiency of a fuel engine
  • · Replies 2 ·
Replies
2
Views
3K