CFD Online Discussion Forums - [mesh manipulation] Dynamic Mesh Diffusivity Problem

Hello all,

I am trying to implement a multi-element dynamic mesh (wing & flap) where both elements rotate independently (Structures.png). The latest issue is that of diffusivity in the dynamic mesh. The trailing edge of the flap is overlapping the surrounding mesh (structured - Trailing edge.png), causing errors and failure to complete any simulation (moveDynamicMesh, pimpleDyMFoam). I am confused because I use the same diffusivity (inverseDistance) that is used in tutorial wingMotion2D_pimpleDyMFoam, but in the wingMotion tutorial, the mesh surrounding the trailing edge does not perceptibly deform locally at all (attached - g.jpg).

Can anyone suggest how I might fix this diffusivity problem? I have tried changing the code of inverseDistanceDiffusivity.C line 110 from

Code:

faceDiffusivity_ = 1/fvc::interpolate(y_);

Code:

faceDiffusivity_ = 100000/fvc::interpolate(y_);

and

Code:

faceDiffusivity_ = 0.00001/fvc::interpolate(y_);

but none have worked. I would appreciate any suggestions. Another issue is at the interface of the two elements. As the flap rotated relative to the airfoil, the mesh turns inside out (Structured - top of hinge.png). Is it possible to put a sliding mesh interface on the flap? Would that be wise?

Regards,

Dan