Hi
I had a general query on the type 2 testing done as per PTC code 10 for compressors. I recollect reading at some point in research literature about the following and would appreciate further in depth input on the part of anyone having more experience :

1. PTC 10 allows Reynold number corrections to be applied during s type 2 test especially if the test bed power and suction conditions are constrained. Yet most end users do no prefer to apply such a correction. I am trying to understand why, besides the reason that they would like the compressor tested to design. I do not see other reasons to not apply the correction.

2. Generally the PTC requires the Mach number and the Vol ratio to be within certain range for the test to be acceptable. I did read somewhere that it is better to calculate the Mach number and vol flow ratios for different stages in a multistage compressor and then covert them to head coff, flow coff and effieicy and then plot this. Finally look at the test plot for head and flow coff with the calculated head vs flow coff to see how much deviation if any exists.

I do not clearly understand how the head coff and flow coff is calculated from the Mach and vol ratio figures and how this process of plotting is accomplished.

Any help will be highly appreciated.

Thanks