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April 13, 2012, 14:07 |
why does drag coefficients turn to negative
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#1 |
New Member
no
Join Date: Mar 2012
Posts: 6
Rep Power: 14 |
I am working on a 2d wings using ANSYS FLUENT 13.0. The fluid is water. The convergence history looks ok for Residual, Cd and Cl, however, the drag coefficients are very close to 0 and turn to negative at last.
Does anyone know what's the problem. Thank you. |
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April 14, 2012, 22:21 |
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#2 |
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no
Join Date: Mar 2012
Posts: 6
Rep Power: 14 |
The problem is solved by entering the force vectors: the lift coefficient (-sin, cos), the drag coefficient (cos, sin).
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April 16, 2012, 13:54 |
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#3 |
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no
Join Date: Mar 2012
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The negative drag coefficient again in a smaller angle of attack.
Why? |
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April 16, 2012, 15:26 |
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#4 |
Member
banty
Join Date: Mar 2012
Posts: 52
Rep Power: 14 |
why u are doing calculating lift and drag coefficient manually. u can report the drag and lift coefficient in fluent even u can set as monitor. plz also check the reference area that is used for calculating drag and lift coefficient.
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