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unisimo April 8, 2009 03:50

lift coefficent of ahmed body
hi,i am using fluent to do external air flow analysis around the ahmed body at 60m/s. the drag coefficent(0.28) is closed to the experiment result(0.285 for slant 25degree),but the lift coefficent(0.001) is far smaller than the experiment result(0.4). I have used several models, unfortunately, there is no improvement on lift coefficient.I have do these in CFX with the same mesh. the Cl is close to the experiment result, but it fluctuate from 0.2 to 0.7

please give me some suggestions


Hertzel May 14, 2009 17:48

could you give some more details about the mesh you used?
how fine it is in the region directly around the body and further away?

how do the velocity plots on some lines behind the body (and on the slant surface) match the ones from the literature or simulations by Lienhart?
(the data of Lienhart's velocity plots can be found easily on the internet)


Ralf Schmidt May 15, 2009 04:11

do you model in 2D? Then, you have to set the area in the reference values panel to the are that that is needed for lift coefficient calculation....

Shamoon Jamshed May 18, 2009 13:30

Well the mesh is structures. All the results, vel profile, stream lines are correct. The only problem is the area. In 2D I dont know how to specify the area for each individual wall!

Fluent manual didnot help

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