ORIGINAL: rctech2k7




I agree, it’s really complicated to determine parameters of an engine, because it takes time and some guts to analyze thermodynamics process. To be practical I just used value on the output side of an engine and get comparison between the test result. It also eliminate other variable including constant... BTW, I've got mistake here, I should consider intake airflow because in reality air accelerates around the turbine and becomes free stream. So even the engine is on a test stand it has airspeed when it's running.

Here's the formula for Thrust from http://www.grc.nasa.gov/WWW/k-12/airplane/turbth.html so we can solve it again.




BTW, rctech2k7 is a short for RCTech2007. Rctech was taken when I signed up but since I started in RC on year 2007 I used 2k7, where ''k'' is derived from a technical prefix kilo.

Good to know that we have someone here with degree of Physics, very interesting... You might help us about adiabatic expansion. BTW, my background is electrical engineering. What I've also learned makes me to appreciate the network and technical part of this hobby specially the high energy performance of our jets, flight control system, etc...

Let's go back to the topic, I tried to approximate using this formula and it's almost the same although the fuel consumption might change it slightly when running at low air density where mass flow to the exhaust will increase...