REFLECTOR: Advance Turbine Power ne Innodyn

[Richard Riley]

At 07:43 PM 10/10/04, you wrote:
>The universal gas law is  P V = n R T.  We are looking at a change in
>temperature due to a change in pressure and volume, so R, the universal gas
>constant, and n, the amount of gas involved, can be dropped out.  We then
>see that the product of pressure and volume is directly proportional to the
>absolute temperature, assuming heat leaking out of the system is small
>(which is reasonable because compression is very rapid).  We certainly
>expect a significant reduction in volume with the 3.5 times increase in
>pressure, so the increase in absolute temperature will be much less than the
>compression ratio.
>
>If we assume an initial temperature of 80 degrees F (about 540 degrees
>Rankine), an increase to 750 degrees F (about 1210 R)  would be a factor of
>2.2.   This would imply a change in volume of only 2.2/3.5 = 0.63 would be
>associated with the 3.5 times increase in pressure, which seems
>unreasonable.  I think the temperature difference is probably overstated, as
>Richard implied.

Thanks, Keith.

I got a courtesy "C" in thermodynamics.  And they gave me that 'cause I was 
the only theater major to have ever taken it as an elective, not because I 
understood enthalpy.