Difference between the thermal and mechanical efficiency

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Discussion Overview

The discussion centers on the distinction between thermal efficiency and mechanical efficiency in the context of Stirling heat engines and heat engines in general. Participants explore definitions and implications of these efficiencies, seeking clarification on their meanings and applications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant expresses confusion regarding the difference between thermal and mechanical efficiency in heat engines, seeking guidance.
  • Another participant suggests that there may not be a difference but questions the use of "mechanical efficiency" in thermodynamic contexts, referencing external sources for clarification.
  • A participant proposes that mechanical efficiency could be defined as the ratio of work done by the gas to the work output of the heat engine, asking for validation of this understanding.
  • There is a suggestion that thermal efficiency might refer to thermodynamic processes, but it could also pertain to real-world, non-ideal processes, indicating a need for clear definitions from sources.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the definitions of thermal and mechanical efficiency, with multiple viewpoints and uncertainties expressed regarding their meanings and applications.

Contextual Notes

Participants note the importance of definitions in understanding the terms, highlighting potential ambiguities in the sources referenced.

Poorneshwar 2
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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
 
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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.
 

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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.
 

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