"High Mach Number flow exists"--tho i m running the sim at 5m/s.

shezi266 · August 13, 2018, 07:09

hello sir,
does this vortex problem affects the results?
thank you

Boris_M · August 13, 2018, 10:12

Yes, that's why there is a warning.
Some result parameters might not be affected but others are.
For example, the pressure opening is defined with a specific pressure and temperature. That temperature is only valid if there is an inflow, then this temperature is used for the inflow. If you have heated air leaving the pressure opening but cooler air coming in through it due to the vortex in the opening, then the average air temperature at the opening will be lower as the vortex causes this issue.

Regards,
Boris

shezi266 · August 14, 2018, 03:02

hello sir ,

you helped me alot sir in my project .

does supersonic flow problem depends on my boundary conditions ?
sometimes there is no this warning at some specific values as i am increasing flow rate or rpm ,this problem appears .

please suggest me how to get rid of this problem , as i think this is last problem which iam facing.

Thanks

Boris_M · August 17, 2018, 09:01

You don't need to worry about the high mach number option in your case. This is still good.
Reason is that the low compressible solver works good enough for a certain range over Mach 1-2.

Which method did you use, sliding or averaging?

Boris

shezi266 · August 18, 2018, 00:25

hello sir ,
iam using averaging method

Boris_M · August 30, 2018, 07:23

Ok, then this should work just fine as it is.

Regards,
Boris

August 13, 2018, 07:09	vortex problem	#21
shezi266 New Member Shahzad Join Date: Jul 2018 Posts: 22 Rep Power: 7	hello sir, does this vortex problem affects the results? thank you

August 14, 2018, 03:02	supersonic flow problem	#23
shezi266 New Member Shahzad Join Date: Jul 2018 Posts: 22 Rep Power: 7	hello sir , you helped me alot sir in my project . does supersonic flow problem depends on my boundary conditions ? sometimes there is no this warning at some specific values as i am increasing flow rate or rpm ,this problem appears . please suggest me how to get rid of this problem , as i think this is last problem which iam facing. Thanks

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August 13, 2018, 10:12		#22
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	Yes, that's why there is a warning. Some result parameters might not be affected but others are. For example, the pressure opening is defined with a specific pressure and temperature. That temperature is only valid if there is an inflow, then this temperature is used for the inflow. If you have heated air leaving the pressure opening but cooler air coming in through it due to the vortex in the opening, then the average air temperature at the opening will be lower as the vortex causes this issue. Regards, Boris

August 17, 2018, 09:01		#24
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	You don't need to worry about the high mach number option in your case. This is still good. Reason is that the low compressible solver works good enough for a certain range over Mach 1-2. Which method did you use, sliding or averaging? Boris

August 18, 2018, 00:25		#25
shezi266 New Member Shahzad Join Date: Jul 2018 Posts: 22 Rep Power: 7	hello sir , iam using averaging method

August 30, 2018, 07:23		#26
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	Ok, then this should work just fine as it is. Regards, Boris