Recently, I want to test a thin flat plate problem both in 2d and 3d in PyFR v1.12.1. The parameters I need are the lift force Fl and lift moment M. The plugin
[soln-plugin-fluidforce-name] is helpful, but seems to contain only the forces in two direction. There are two directions I can follow. One is to add the third component to the plugin in solver stage. I’ve checked the
fluidforce.py under the
plugins folder, which is quite hard for me to understand. I also looked over the Ansys Fluent Theory Guide, which details the calculation of the total force component and total moment:
Fa = a·Fp + a·Fv
Ma = rAB×Fp + rAB×Fv
Where a means specified force vector, Fp and Fv means pressure and viscous force vector, respectively. rAB means moment vector, point from moment center A to force origin point B. So if I want to get the moment, I need a position vector and a force vector. How can I extract the vectors and accomplish it in the plugin? Or in a cumbersome way using the
[soln-plugin-sampler] instead, which would burden my work enormously.
The other way is to obtain the moment term with paraview filters in post-process stage. With the filter such as
GenerateSurfaceNormals, etc. several tutorials can be found on YouTube. But in most cases, the output files are in .case format from OpenFOAM. It would be confusing to do the same operation since many filters are gray to pick on both 2d and 3d cases.
Really hope someone can offer me any suggestion, and thanks a lot in advance for your kind help!