What is turbulence flux relating to EBC's?
Hi,
I am trying to prescribe an inlet turbulence intensity for flow past a square cylinder. I believe that This can be accomplished using an essential boundary condition; however, I need to know more details.
How is turbulence diffusion flux defined in AcuSolve? It would be great to get a detailed understanding of this option.
Here it's used in hwcfd,
Here is what I was able to find in the documentation for hwcfd
Thanks,
Peter Parrish
Find more posts tagged with
Altair EmployeeI would suggest using the option of intenstiy from the HM-CFD interface, unless you are absolutely sure about going the EBC way.
I will try to find out exact definition of turbulence_flux.
As ydigit shows, with the turbulence tab in the BCs for a Constant velocity inlet, you can define the turbulence intensity and length scale. Those are not available when using the Profiled options for the inlet.
Thanks for your help. I believe everyone may benefit from a better understanding of turbulence flux. I'm guessing it is the same as percent turbulence intensity as seen in the constant inlet condition menus.
The reason I would like to use EBC is to possibly change the turbulence intensity depending on its position along a given special dimension.
Altair EmployeeThanks for your help. I believe everyone may benefit from a better understanding of turbulence flux. I'm guessing it is the same as percent turbulence intensity as seen in the constant inlet condition menus.
The reason I would like to use EBC is to possibly change the turbulence intensity depending on its position along a given special dimension.
It is definitely not the same as percent turbulent intensity. The units of turbulence flux are kg/sec^2, where turbulence intensity is unitless. (Turbulence_flux is generally type = free, meaning it falls out of the solution based on the other settings/values.) I don't see any method to specify a profile of turbulence intensity on a single surface. Probably the best you could do is split the inlet surface into a series of sections, on each of which you could specify a different turbulence intensity. It will be stair-stepped instead of a smooth profile, but not constant.
Altair EmployeeThanks for your help. I believe everyone may benefit from a better understanding of turbulence flux. I'm guessing it is the same as percent turbulence intensity as seen in the constant inlet condition menus.
The reason I would like to use EBC is to possibly change the turbulence intensity depending on its position along a given special dimension.
It is definitely not the same as percent turbulent intensity. The units of turbulence flux are kg/sec^2, where turbulence intensity is unitless. (Turbulence_flux is generally type = free, meaning it falls out of the solution based on the other settings/values.) I don't see any method to specify a profile of turbulence intensity on a single surface. Probably the best you could do is split the inlet surface into a series of sections, on each of which you could specify a different turbulence intensity. It will be stair-stepped instead of a smooth profile, but not constant.
I would suggest using the option of intenstiy from the HM-CFD interface, unless you are absolutely sure about going the EBC way.
I will try to find out exact definition of turbulence_flux.