FW-H acoustic permeable surface in Fluent

levivad · July 31, 2013, 09:15

I'm simulating an unsteady, low Mach number (M<0.1) flow. I also want to measure the generated sound.
I know that to find the sound caused by vortices I must enclose them by a "permeable surface" and define it as the sound source.
This also means that I must use compressible simulations with the ideal gas law.

The question remaining is whether I must reduce the time step to achieve a Currant number less then 1, even if the flow frequency is very small?

Since I'm capturing the boundary layer, this will cause a time step 3 orders of magnitude smaller then the flow time scale.

HPUR · March 24, 2014, 15:20

Hi! I'm trying to simulate jet noise in subsonic nozzles and I came across your post here.I would like to know how I can introduce an acoustic permeable surface in order to enclose the noise sources along my computational domain.I appreciate it if you could give me some guidance about it.

jasonbot · April 7, 2014, 08:53

Quote:

Originally Posted by HPUR

Hi! I'm trying to simulate jet noise in subsonic nozzles and I came across your post here.I would like to know how I can introduce an acoustic permeable surface in order to enclose the noise sources along my computational domain.I appreciate it if you could give me some guidance about it.

Create a new named selection in your geometry/mesh that encloses your model.

July 31, 2013, 09:15	FW-H acoustic permeable surface in Fluent	#1
levivad New Member Join Date: May 2013 Posts: 12 Rep Power: 13	I'm simulating an unsteady, low Mach number (M<0.1) flow. I also want to measure the generated sound. I know that to find the sound caused by vortices I must enclose them by a "permeable surface" and define it as the sound source. This also means that I must use compressible simulations with the ideal gas law. The question remaining is whether I must reduce the time step to achieve a Currant number less then 1, even if the flow frequency is very small? Since I'm capturing the boundary layer, this will cause a time step 3 orders of magnitude smaller then the flow time scale.

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March 24, 2014, 15:20		#2
HPUR New Member Join Date: Mar 2014 Posts: 3 Rep Power: 12	Hi! I'm trying to simulate jet noise in subsonic nozzles and I came across your post here.I would like to know how I can introduce an acoustic permeable surface in order to enclose the noise sources along my computational domain.I appreciate it if you could give me some guidance about it.