Re: [Phys-L] Carnot (?) efficiency of non-Carnot cycles

[Bernard Cleyet <bernard@cleyet.org>]

On 2015, Mar 05, , at 09:14, Carl Mungan <mungan@usna.edu> wrote:

> "For an ideal regenerator, it contributes
> nothing to the energy budget and entropy budget when summed
> over a cycle.  Whatever it takes it gives back over the
> course of a cycle."
>
> That's very clever. I can see indeed that we could undo in the isochoric
> depressurization what we did in the isochoric pressurization step, at least
> for an ideal device.
>
> Now what is such a device (I'll accept a real one and idealize it in my
> mind), and why don't intro textbooks mention it given that this seems a
> pretty essential part of non-Carnot cycles?
>
> -- 
> Carl E Mungan, Assoc Prof of Physics  410-293-6680 (O) -3729 (F)
> Naval Academy Stop 9c, 572C Holloway Rd, Annapolis MD 21402-1363
> mailto:mungan@usna.edu     http://usna.edu/Users/physics/mungan/
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The Stirling cycle is a highly advanced subject that has defied analysis by many experts for over 190 years. Highly advanced thermodynamics is required to describe the cycle. Professor Israel Urieli writes: "...the various 'ideal' cycles (such as the Schmidt cycle) are neither physically realizable nor representative of the Stirling cycle".[2]

The analytical problem of the regenerator (the central heat exchanger in the Stirling cycle) is judged by Jakob to rank "among the most difficult and involved that are encountered in engineering".[3   


http://en.wikipedia.org/wiki/Stirling_cycle  

bc