Turbulent Intesity Inlet and outlet cavitating flow in Nozzle

SPH_CFD · April 28, 2015, 12:29

Dear all,

I have a problem with cavitating flow inside nozzle.
I have a convergent-divergent Nozzle with length=600 mm and diameter=50mm, pressure inlet =171000 Pa and outlet=109200 Pa. working fluid is water with temperature =373.3 K.

My problem is that I use K-Omega solver and I do not have experience to set Turbulent intensity bcs (both inlet and outlet).

Do you have experience about this value (or range of this value). Please let me know.

Thanks in advance

Kozan · April 29, 2015, 03:54

Hello, I'm solving similar case right now. It is C-D nozzle with diameter of 0.053 m on the inlet and 0.02 m in the narrowest part. (2D, axisymmetric, RSM, S-S model of cavitation, transient, BC: Vel. in., pres. out.). My work is focused on the dynamics of the cavitating flow.

I'm not very familiar with K-Omega model of turbulence, but I heard that its implementation in the Fluent isn't the best and realizable k-eps should produce better results (but I'm not sure about that). Anyway there is some calculator for the values you need.

You can find it here: http://www.cfd-online.com/Tools/turbulence.php
There is some documentation too, so maybe it will be useful for you.

If you want to share some experience, please feel free to write me a pm maybe it could be useful for both of us.

Good luck and have a nice day

SPH_CFD · April 29, 2015, 08:51

Dear Kozan,

Thank you so much for your help
I have realized that we simulate on the same model. However, I try 3D nozzle. I also try 2D and it is very simple to converge.
Could you please share with me some information about your input output? of some test cases. I just want to be sure that FLUENT can do this thing.

April 28, 2015, 12:29	Turbulent Intesity Inlet and outlet cavitating flow in Nozzle	#1
SPH_CFD Member Quang Le Dang Join Date: Jun 2012 Posts: 61 Rep Power: 13	Dear all, I have a problem with cavitating flow inside nozzle. I have a convergent-divergent Nozzle with length=600 mm and diameter=50mm, pressure inlet =171000 Pa and outlet=109200 Pa. working fluid is water with temperature =373.3 K. My problem is that I use K-Omega solver and I do not have experience to set Turbulent intensity bcs (both inlet and outlet). Do you have experience about this value (or range of this value). Please let me know. Thanks in advance

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April 29, 2015, 03:54		#2
Kozan New Member jiri kozak Join Date: Jan 2013 Posts: 21 Rep Power: 13	Hello, I'm solving similar case right now. It is C-D nozzle with diameter of 0.053 m on the inlet and 0.02 m in the narrowest part. (2D, axisymmetric, RSM, S-S model of cavitation, transient, BC: Vel. in., pres. out.). My work is focused on the dynamics of the cavitating flow. I'm not very familiar with K-Omega model of turbulence, but I heard that its implementation in the Fluent isn't the best and realizable k-eps should produce better results (but I'm not sure about that). Anyway there is some calculator for the values you need. You can find it here: http://www.cfd-online.com/Tools/turbulence.php There is some documentation too, so maybe it will be useful for you. If you want to share some experience, please feel free to write me a pm maybe it could be useful for both of us. Good luck and have a nice day

April 29, 2015, 08:51		#3
SPH_CFD Member Quang Le Dang Join Date: Jun 2012 Posts: 61 Rep Power: 13	Dear Kozan, Thank you so much for your help I have realized that we simulate on the same model. However, I try 3D nozzle. I also try 2D and it is very simple to converge. Could you please share with me some information about your input output? of some test cases. I just want to be sure that FLUENT can do this thing.