Moving mesh part 2
Posted October 8, 2012 at 21:37 by sunliming
Quote:
Originally Posted by lr103476
Hi,
The mesh motion works using the latest development code using the oscillatingFixedValue boundary condition. Now I am considering oscillating bodies (flat plates and cylinders) on different grids at low Reynolds numbers to see how the grid motion behaves.
I've got the following questions/remarks:
1) On coarse grids the meh motion performs very nicely, but on finer grids the mesh gots distorted near the body causing the flow solver to diverge. Since the oscillatory motion stays the same, but the cells are smaller (on the finer grid) the relative cell displacement is increased, i.e. the boundary of the body moves multiple cell sizes within one timestep. Besides choosing a very very small timestep, is there a good solution for this??
2) So, what are the ideal motion solver settings for this kind of problems?
3) At my place, another moving mesh method is developed using radial basis functions. This method is capable of using very large time steps without severe mesh destortion near the moving body boundary. How difficult is implementing such a new mesh motion algorithm in OpenFOAM?, or is this almost impossible?
4) I am also trying to expand the oscillatoryFixedValue boundary conditions towards a 6 DOF boundary condition which could handle arbitrary functions for 6 variables (not only oscillatory functions). Do you think this is feasible? Is it smart to start with the movingFlapFvMesh class from OpenFoam 1.2?
5) In the development sources, I am using, a top level Fluid Structure Interaction solver is present, icoFsiFoam. Is there also a tutorial available for this, just as an example how to define a problem using this solver. Unfortunately I haven't seen prof. Jasak's presentation at the 5th ICCSM, but I have read the paper and I'm impressed.
Best regards, Frank
The mesh motion works using the latest development code using the oscillatingFixedValue boundary condition. Now I am considering oscillating bodies (flat plates and cylinders) on different grids at low Reynolds numbers to see how the grid motion behaves.
I've got the following questions/remarks:
1) On coarse grids the meh motion performs very nicely, but on finer grids the mesh gots distorted near the body causing the flow solver to diverge. Since the oscillatory motion stays the same, but the cells are smaller (on the finer grid) the relative cell displacement is increased, i.e. the boundary of the body moves multiple cell sizes within one timestep. Besides choosing a very very small timestep, is there a good solution for this??
2) So, what are the ideal motion solver settings for this kind of problems?
3) At my place, another moving mesh method is developed using radial basis functions. This method is capable of using very large time steps without severe mesh destortion near the moving body boundary. How difficult is implementing such a new mesh motion algorithm in OpenFOAM?, or is this almost impossible?
4) I am also trying to expand the oscillatoryFixedValue boundary conditions towards a 6 DOF boundary condition which could handle arbitrary functions for 6 variables (not only oscillatory functions). Do you think this is feasible? Is it smart to start with the movingFlapFvMesh class from OpenFoam 1.2?
5) In the development sources, I am using, a top level Fluid Structure Interaction solver is present, icoFsiFoam. Is there also a tutorial available for this, just as an example how to define a problem using this solver. Unfortunately I haven't seen prof. Jasak's presentation at the 5th ICCSM, but I have read the paper and I'm impressed.
Best regards, Frank
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