The order of magnitudes of output-PPRIME is wierd.

Amber0922 · December 7, 2023, 07:34

Hi,everyone.

I am currently seeking to obtain the mean fluctuating pressure in my simulation, and I have observed that the volume outputs provide a variable labeled "PPRIME," which seems to align with my requirements. However, I've noticed that the order of magnitudes for PPRIME appears unusual. My freestream pressure is 2500 Pa, and the Mach number is 6, whereas PPRIME exhibits magnitudes on the order of 10^8 or even larger. I am inclined to believe that SU2 might not be applying a root treatment to PPRIME. I would appreciate your insights on this matter.

Furthermore, if there is a convenient method to extract the pulsation characteristics of the flow, I would be grateful for your guidance. Thank you for your patience and assistance.

Best regards,

Zhang.

bigfootedrockmidget · December 7, 2023, 10:01

Hi,

Yes, pprime is p' * p'

So it should actually be called PPPrime,, just like we have UUPRIME and UVPRIME

But we also have RMS_P as output.

Amber0922 · December 7, 2023, 22:20

Hi, Midget

Thanks for your patient reply, it helps me a lot.I have a follow-up question regarding RMS_P, the order of magnitudes is 10^6 to 10^11. As I suspect it may not involve the square root operation, or it could potentially represent the RMS of total pressure.

Thank you once again for your assistance.

December 7, 2023, 07:34	The order of magnitudes of output-PPRIME is wierd.	#1
Amber0922 Member Zhang Join Date: Mar 2023 Posts: 72 Rep Power: 3	Hi,everyone. I am currently seeking to obtain the mean fluctuating pressure in my simulation, and I have observed that the volume outputs provide a variable labeled "PPRIME," which seems to align with my requirements. However, I've noticed that the order of magnitudes for PPRIME appears unusual. My freestream pressure is 2500 Pa, and the Mach number is 6, whereas PPRIME exhibits magnitudes on the order of 10^8 or even larger. I am inclined to believe that SU2 might not be applying a root treatment to PPRIME. I would appreciate your insights on this matter. Furthermore, if there is a convenient method to extract the pulsation characteristics of the flow, I would be grateful for your guidance. Thank you for your patience and assistance. Best regards, Zhang.

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December 7, 2023, 10:01		#2
bigfootedrockmidget Senior Member bigfoot Join Date: Dec 2011 Location: Netherlands Posts: 676 Rep Power: 21	Hi, Yes, pprime is p' * p' So it should actually be called PPPrime,, just like we have UUPRIME and UVPRIME But we also have RMS_P as output.

December 7, 2023, 22:20		#3
Amber0922 Member Zhang Join Date: Mar 2023 Posts: 72 Rep Power: 3	Hi, Midget Thanks for your patient reply, it helps me a lot.I have a follow-up question regarding RMS_P, the order of magnitudes is 10^6 to 10^11. As I suspect it may not involve the square root operation, or it could potentially represent the RMS of total pressure. Thank you once again for your assistance.