An Observation (thermodynamic efficiency)

According to the commonly taught basic thermodynamics, the Carnot cycle's theoretical max. efficiency (dubbed e for lack of special characters) is given by

e = ( T_upper - T_lower ) / T_upper


or 1 - T_lower/T_upper


how you arrive there is not my point at this time, because it's immediately obvious that, while the efficiency of a thermally driven engine can, of course, be given as Energy_out / Energy_in , assessing Excess Temperatures (ie. above ambient temp) before and after use, is just as valid and much less complicated, as long as the process starts from ambient pressure and eventually returns there.

in case you did not notice, the enumerator reflects just that already, the denominator otoh, does not...

i'll leave the conclusions to you and post back on demand.

Is the math correct on the page you used as reference? Wikipedia shows something else, and the page you cited had some odd looking things with the math.

Uhmmm.. Calculus check on Aisle 2, please!

Here's Wikipedia:
en.wikipedia.org...

the page i linked was just for reference of Carnot cycle's maximum efficiency, which is given as

1 - T_c /T_h

in Wikipedia, just as by my link. it is completely independent from the observation that, at a given pressure, temperature itself is a sufficent indicator of energy content. if you are calculating ratios, the involved constants cancel.

Byrd, i suggest you (manually) replace absolute temperatures with relative ones (we are not heating from -273C, are we) ie. T_x --> ( T_x - T_ambient) .

because, efficiency is obviously given by (available temperature delta) / ( actually used temperature delta).

huh? noone caught the error?

it's (used_temp_delta) / (available_temp_delta) , of course, not the other way around, ( efficiency is supposed to remain < 1 after all). looks like i might as well forget about posting such things.