How to calculate the drag coefficient C_D and lift coefficient C_L

Alex

How to calculate the drag coefficient C_D and lift coefficient C_L

zilonglee

Hi, thanks for your great effort. My question: is there a post-processing tool to calculate the drag coefficient C_D and lift coefficient C_L, when we do the simulations, such as flow around cylinders, spheres, or any other objects with complex shapes. Kindly Regards.

Alex

No, in a direct way... you can use PartVTK, MeasureTool or ComputeForces to obtain other magnitudes that can be used to derive those coefficients

Regards

zilonglee

Thanks, Alex. Would you mind writing out the specific procedures? So that I can follow.

Regards

Asalih3d

@zilonglee

For an example you could use the acceleration values which your boundary is experience (the acceleration which the bound has, must be the same as the fluid is pushing it with) and then timing this by mass you can get the force experience by the boundary object. Then it is trivial to solve for C_D.

Play around a bit with the PartVTK export csv option and it will hopefully be easy enough.

Alex

ComputeForces.exe already computes the forces exerted onto an object (fixed boundary, moving or floating body) defined by one MK value

Regards

zilonglee

Thanks, Asalih3d and Alex.