Divergent results between laminar model and blasius result (Asymptotic)

ANSYSCOMP

Hello

I am working about fluid flow over flat plate Re: 10E5.

The longitudinal velocity exceeds the inlet velocity

InkedChartV1 2 2_LI.jpg

I tried another meshing but the same result.

After, I used different VISCOUS MODEL in the FLUENT. The result shows that the RSM is more adapted than laminar model to Blasius result. Despite the RSM treats the turbulent model.

Capture d’écran 2021-02-11 120050.jpg

ANSYSCOMP

Kremella

Hi,

Couple of things:

1. A flat plate Re number of 1E6 (or 10E5) is somewhat high for a laminar flow. The flow tends to transition at around a critical Re of 5E5. If you wish to keep the flow Laminar, reduce the Re number below 5E4 (at least) to be safe. In your case, the flow might be transitioning to Turbulence and therefore is showing a different profile than the Blasius.
2. Have a look at the following example. I would like to particularly draw your attention to the mesh. You will need a mesh like this one to validate your model.

https://courses.ansys.com/index.php/courses/laminar-boundary-layer-theory/lessons/simulation-examples-homework-and-quizzes-6/topic/laminar-flow-over-a-flat-plate-simulation-example/

I hope this helps.

Karthik

ANSYSCOMP

Typing error : Re=1E5.

For my mesh :

Kremella

Hi,

You will need a much better resolution on your mesh, especially near the wall of the flat plate. I'd strongly urge you to have a look at the mesh file from the simulation example I shared with you. This is from our AICs. This would help you get a good understanding of what you need to do.

Thanks.

Karthik

ANSYSCOMP

Thank you

I will come back to you