[Julian121]

I am doing a numerical simulation of NASA Rotor 37 for validation.
I used the geometry for Rotor 37 from Turbogrid tutorials and applied a tip clearance of 0.356 mm according to experimental results.
The boundary conditions that I used are as follows:
Inlet: Total Pressure 101325 Pa, Total Temperature 288.15 K
Outlet: Mass Flow at design which is 20.19 kg/s / Number of blades which is 36.
Rotational speed: 17188.7 rpm
According to the tutorial on Rotor 37, the blade row contains 36 blades that revolve about the negative Z-Axis. Does this mean that angular velocity should be -17188.7 rpm or 17188.7?
I am expecting to reach the design pressure ratio which is 2.106, but the outlet pressure becomes less than inlet pressure no matter if I use 17188.7 or -17188.7!
I do not know what I have missed. Can someone please help?

[Opaque]

Based on the axis shown in figure 2, and that Rotor 37 is for a compressor, the value for angular velocity must be negative.

[Julian121]

I used negative value but still the pressure ratio becomes less than one.
It seems that the blade row acts like a turbine instead of a compressor!
Why does this happen?

[Opaque]

One of the tutorials in CFX is Rotor 37 (see FourierBladeRow tutorial). There is a steady state setup, so you can compare setup

[Julian121]

Thank you. I followed the tutorial. Why sliding mesh was used in this tutorial?
Which one of "Total Pressure" or "Total Pressure in Stationary Frame" expression at outlet should be used to calculate the pressure ratio in the isolated rotor 37?
I think the reason why I was getting smaller outlet total pressure was that I was using total pressure which was based on relative velocity rather than absolute velocity.