BOUNDARY LAYER SIZE IN SIMLAB

Sivaprakash_V
Sivaprakash_V Altair Community Member
in Community Q&A

Hi,

I am performing a CFD Analysis of Air blower using SIMLAB to find the Flow rate of it.
I have done my meshing. But I have some doubt in Boundary and its size.
For Air blower model, How to choose the Boundary layer thickness and first layer height.
If I choose Y+ based, I am having HM CFD, Y+ calculator is there. In Y+ based, What I consider as Desired Y+ value and Reference length.
Which one should I take Air blower Inlet diameter or blade length of impeller as reference length and Y+ value?

Else Is there any method to find these layers values?

Thanks & Regards,
Sivaprakash.

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Best Answer

  • acupro
    acupro
    Altair Employee
    Answer ✓

    These Y+ estimators are typically based on flat plate (for external flows) or pipe (for internal flows) behavior. They can be useful for a rough initial guess, but always best to check resultant Y+ values from the solution once solved, then adjust the boundary layer (and other mesh) as necessary to get good results. The turbulence models in AcuSolve are valid to Y+ about 300. Lower Y+ gives better surface behavior resolution/accuracy, at the cost of more mesh.

Answers

  • acupro
    acupro
    Altair Employee
    Answer ✓

    These Y+ estimators are typically based on flat plate (for external flows) or pipe (for internal flows) behavior. They can be useful for a rough initial guess, but always best to check resultant Y+ values from the solution once solved, then adjust the boundary layer (and other mesh) as necessary to get good results. The turbulence models in AcuSolve are valid to Y+ about 300. Lower Y+ gives better surface behavior resolution/accuracy, at the cost of more mesh.

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