[olekiar]

Hello,

We have a project at the university where the first part involves verification of correct drag coefficient from a splitplate. In our simulation we consistently get a drag coefficient which is about 60 % higher then Blasius values.

We have researched if the problem is caused by the mesh, but the problem remains regardless of the refinement of the mesh. Below is a picture of the mesh used, with grading towards the splitplate.



We were wondering if anyone would be so kind as to help us figure out why we get an incorrect drag coefficient from this case.

The simulation tells us that the drag coefficient Cd = 0.973, while according to Blasius it should be Cd = 0.594.

Below are links to all the information you'll need, even the full OpenFOAM case for you to run.

OpenFOAM: splitplate.zip

We have two ways of figuring out the drag. One way is included in the controlDict file, which prints the coefficients to a file in the folder splitplate/postProcessing/forceCoeffs. The other way is to extract the velocities one cell above the splitplate, by the use of a sampleDict file, and calculated the drag ourselves. The links below are to a .xls and a .m file. The excel file contains the Blasius solution, which we import to Matlab. The matlab script converts eta to x.

Blasius solution
Matlab script

Thanks in advance!