Isentropic Efficiency Compressor And Turbine

Hallo everyone!

I would like someone to explain me/remind me why the definition of isentropic efficiency for the turbine and the compressor is different.

Please see the attached document.

Thank you in advance!

Hi,

Consider this resource to support your query : http://processengine...damentals.html#

note : let you use your favorite search engine .

It's also good to use a H-S diagram to visualize the work !

Good luck

Breizh 

Edited by breizh, 16 February 2020 - 06:09 AM.

Thank you so much for the valuable documents!!!

The answer is hidden in heat engine and heat pump. 

Am I right?

hi ,

You need to perform a heat balance for 2 conditions : isentropic and real .

1= initial state

2 = final state

m*(h2-h1) = W+Q with  Q# 0 adiabatic

W :work 

Q :heat 

m : mass flow rate kg/s

hi :specific enthalpy 

Compression : h2 isentropic is smaller than h2 real  ; RC  = (h2 is-h1)/(h2 real -h1) <1

turbine means expansion :  h2 real is bigger than h2 isentropic ; RD = -Wreal /-W is  =( h1-h2real )/(h1-h2is) <1

Again use a diagram H-S where you plot h1, h2  isentropic and h2 real at P1 and P2 .

https://thermodynami...and-compressor/

My view

Breizh

Edited by breizh, 19 February 2020 - 02:17 AM.