[Piquero]

Hi guys,

I would like to know your opinion and advice on the following problem I have been working on lately.

I am studying the flow over an airfoil at a high Mach number. What I am trying to look into is how much heat I can dissipate when I impose a high temperature on a particular region of that airfoil. That is, I want to increase the wall temperature on that region only, and let the rest of the airfoil as is (adiabatic). I was thinking of using a UDF to define a temperature profile; however, while it is ok for the region where I have the increased temperature, I also need to define another value for the rest of the wall. This gives rise to the problem I have been having, which is that I do not know how to make sure that there is heat transfer only on the region I define the temperature on, while having zero heat transfer on the rest of the airfoil wall. In other words, I do not know whether it's possible to define a temperature on a region for an adiabatic wall boundary condition or not.

Modifying the mesh so that I can have one dedicated boundary for the temperature boundary condition and another for the adiabatic region is not an option, so I was hoping to know if there is a way to do this using an UDF.

Hope it makes sense. I would highly appreciate any suggestion.

Best regards

[AlexanderZ]

do you mesh solid part of airfoil? I assume that yes

if you want to prevent heat flux from one zone to another you can do following trick:
you need to divide your airfoil into 2 parts - hot_region, cold_region
in boundary conditions find the boundary between this reagions, by default it could look like:
interior-hot_region-cold_region

change boundary type from interior to wall

interior-hot_region-cold_region_shadow will be created

open interior-hot_region-cold_region and change thermal conditions in Thermal tab from Coupled to heat flux

heat flux = 0 means adiabatic boundary condition
press apply

there will be no heat transfer between this two zones

[aved]

I am trying a case with a 2d rectangular channel having a supersonic flow (pressure inlet and pressure outlet boundary condition). The lower wall is set with a heat flux value of 5000W/m^2. Mine is a very simple case - compressible flow with heat addition. But the heat provided from the bottom wall does not have a noticeable effect on the flow. Can someone suggest an alternative method or explain my mistake. I used the k-epsilon model. Should I turn on gravity because the temperature change is seen near the wall which is also due to friction and not this heat flux.