PPRuNe Forums - View Single Post - Why do turbine engines require a compressor section
Old 8th Jan 2012, 17:30
  #138 (permalink)  
chris weston
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Crabman 137


Crabman;

I think Oggers and Turbine D et al are right here, I suggest that Slippery P is wrong.

It's true that compression will elevate the temperature of gas phase molecules and that that takes us in the right direction, but it's a fairly trivial contribution relative to the enhanced combustion processes so nicely described by Turbine D in post 135.

Let's stay with the notion of temperature change in gas turbines.

Do the Maths; remember these are fully open systems as thermodynamically they exchange matter and energy with the surroundings.

ΔT1 and the energy from the compression of the gases (courtesy of Van der Waals + Dipole-Dipole et al bond formation) will be, at very best, 100s of degrees C or kJ if you want to calculate the energy released and (unless we're in ram jet territory which I guess we're not) is far less than we require for the energy needed for the compression process.

ΔT2 and the energy released to the surroundings from the enhanced ΔHc (combustion processes see post 128) will be orders of magnitude greater than that needed for the compression and therefore available to do useful work - such as provide thrust.

CW
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