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-   -   Drag and Lift forces extremely low (http://www.cfd-online.com/Forums/fluent/47067-drag-lift-forces-extremely-low.html)

João Lourenço January 19, 2008 08:00

Drag and Lift forces extremely low
 
I am trying to perform an aerodynamic characterization of an aircraft. I created an unstructured mesh using Ansys ICEM and imported it to Fluent. The mesh is relatively good but still has a small number of bad quality cells.

I ran a case using an AOA of 6 degrees and monitored the residuals, including turbulent quantities and both CL and CD. The results I got for CL and CD were extremely low. For CL around 10E-4 and CD around 10-5.

I've checked that the scaling of the mesh was correct, the references values were also correct, the boundary conditions were well defined, the force vectors were OK and that the surfaces I am monitoring the forces on were just the ones on the aircraft surface.

I ran out of ideas! Can anyone please help me?

Thank you in advance for your patience and time spent reading this long post.

Regards, Joo

bharat January 19, 2008 18:04

Re: Drag and Lift forces extremely low
 
check the units

João Lourenço January 19, 2008 18:19

Re: Drag and Lift forces extremely low
 
I checked the units too.

Thanks anyway!

Sham January 19, 2008 18:39

Re: Drag and Lift forces extremely low
 
I suggest that you model in Gambit using metres.

Sham.

bachi January 28, 2008 14:25

Re: Drag and Lift forces extremely low
 
i too found the same problem now, if you got any solution for this please help me.

Thank you in advance if have a solution.



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