2D airfoil simulation

A subforum specific to the development of the OpenFoam-based workbenches ( Cfd https://github.com/qingfengxia/Cfd and CfdOF https://github.com/jaheyns/CfdOF )

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techGuy
Posts: 126
Joined: Sat Jun 18, 2022 12:48 am

Re: 2D airfoil simulation

Post by techGuy »

herbk wrote: Tue Mar 21, 2023 7:33 am
thschrader wrote: Sun Sep 11, 2022 10:07 am Result:
lift upper wing: 5,4 N/m
lift lower wing: -0,08 N/m (yes, minus lift!)
Would be better to use the upper wing alone...
Try it... ;)
I would say: without the lower wing the upper wing produces distinctly less lift.
It's all about the flow and detatched flow. If the flow isn't attached on the lower wing it won't help the upper wing. If the upper wing has fully attached flow without the lower wing, the lower wing won't help it. If the lower wing causes the flow to detach on the upper wing, it will hurt it.

Where multi element wings come into their best is at high angles of attack where the flow would detach from the upper wing. There the flow through the slot will keep it attached to both the upper wing and the lower wing.
techGuy
Posts: 126
Joined: Sat Jun 18, 2022 12:48 am

Re: 2D airfoil simulation

Post by techGuy »

thschrader wrote: Tue Mar 21, 2023 2:01 pm 15 m/s inlet speed, 4 deg AoA
The original case was 5m/s IIRC.
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