I Difference between the thermal and mechanical efficiency

AI Thread Summary
The discussion centers on the confusion between thermal and mechanical efficiency in Stirling heat engines. Mechanical efficiency is described as the ratio of work done by the gas to the work output of the engine, while thermal efficiency relates to the thermodynamic performance of the engine. Participants emphasize the importance of clear definitions from sources discussing these terms. There is a consensus that mechanical efficiency should not be used interchangeably with thermal efficiency. Understanding these distinctions is crucial for accurate analysis of heat engine performance.
Poorneshwar 2
Messages
11
Reaction score
0
Hello, I'm confused between the difference between the thermal and mechanical efficiency of a Sterling heat engines or heat engines in general. I hope you could be able to guide and help me. Thank you
 
Science news on Phys.org
I don't think there is a difference, but I wouldn't use the term "mechanical efficiency" to refer to a thermodynamic system. Where did you hear it?

[Edit] Google tells me "mechanical efficiency" can be used to describe the mechanical output of a real engine (different from themal/thermo efficiency).
 
I read about the mechanical efficiency of the heat engine in this article. I think that it is the ratio between Qh(work done by the gas) and Wout(work that the heat engine has done). Am i thinking in the right way?

Also, what does thermal efficiency of a heat engine refer to?

Thank you.
 

Attachments

  • Screenshot 2022-05-09 at 8.46.02 PM.png
    Screenshot 2022-05-09 at 8.46.02 PM.png
    83.7 KB · Views: 129
Poorneshwar 2 said:
I read about the mechanical efficiency of the heat engine in this article. I think that it is the ratio between Qh(work done by the gas) and Wout(work that the heat engine has done). Am i thinking in the right way?
That sounds right, but your source should include the definition if it is introducing the term.
Also, what does thermal efficiency of a heat engine refer to?
I would think thermal means thermodynamic, but it is possible they are also referring to a real-world, non-ideal process. But again, the text you are reading it from should define it.
 
I was watching a Khan Academy video on entropy called: Reconciling thermodynamic and state definitions of entropy. So in the video it says: Let's say I have a container. And in that container, I have gas particles and they're bouncing around like gas particles tend to do, creating some pressure on the container of a certain volume. And let's say I have n particles. Now, each of these particles could be in x different states. Now, if each of them can be in x different states, how many total...
Thread 'Why work is PdV and not (P+dP)dV in an isothermal process?'
Let's say we have a cylinder of volume V1 with a frictionless movable piston and some gas trapped inside with pressure P1 and temperature T1. On top of the piston lay some small pebbles that add weight and essentially create the pressure P1. Also the system is inside a reservoir of water that keeps its temperature constant at T1. The system is in equilibrium at V1, P1, T1. Now let's say i put another very small pebble on top of the piston (0,00001kg) and after some seconds the system...
Back
Top