CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Visualization & Post-Processing (https://www.cfd-online.com/Forums/visualization/)
-   -   I don't understand these results for my boundary layer simulation with a moving wall (https://www.cfd-online.com/Forums/visualization/247464-i-dont-understand-these-results-my-boundary-layer-simulation-moving-wall.html)

Red36925143131 February 6, 2023 10:17

I don't understand these results for my boundary layer simulation with a moving wall
 
4 Attachment(s)
Hello, I wanted to try to simulate a flow around a profile (I did it quickly so it may not be really "clean") and compare the flow between a profile with a moving wall and one with a static wall.

The input velocity was 50m/s and the angle was 15°, I got this :


Attachment 93246
Attachment 93245

The first picture is with a mobile wall condition (with V = 50m/s), and what I don't understand is that I always heard that aerodynamic stall was a boundary layer separation where the boudary layer enlarges, but if the boundary layer has a velocity of 50m/s, why is there static air here ?

Also I tested with an angle of 0 but with an input velocity of 150m/s and I got this :

Attachment 93248
Attachment 93247


The three last values (at the bottom) are firstly the drag for the moving (or static) wall, secondly the lift force (not coefficient) of the whole profile, and lastly the drag force for the whole profile. And we can observe a lift force of -100N whereas it is a symetric profile with an angle of 0, there shouldn't be a lift force

I used k-omega SST model as I heard it was adapted for these simulations.

Thanks in advance


All times are GMT -4. The time now is 18:00.