9FA Compressor efficiency

Hi all,

Could somebody help me with the following, Our 9FA gas turbine has gone through a major overhaul where most of the turbine hardware was changed along with some compressor hardware changed.

We are currently seeing a loss of about 1% power output based on the performance test.

How best can i check the efficiency of the compressor?
Which would be best Isentropic or Polytropic?
I have good data pre and post overhaul.

Many thanks,
Steve

Isentropic efficiency will do the job provided you have all the required data before and after major shutdown. If the problem has something to do with the compressor efficiency good input data shall able to tell you what is going on...