[shach934]

Hi foamers,
I am wandering if the multiregion solver like chtMultiRegionFoam support dynamicMesh. By dynamicMesh, i mean solid moving part, not dynamic refine mesh. Anyone has experience with it?
Thanks1

[Tobi]

Hi,


simple answer. No it is not implemented. The meshes are derived from the fvMesh class and not the dynamic mesh class.

   forAll(fluidNames, i)                                                       
    {                                                                           
        Info<< "Create fluid mesh for region " << fluidNames[i]                 
            << " for time = " << runTime.timeName() << nl << endl;              
                                                                                
        fluidRegions.set                                                        
        (                                                                       
            i,                                                                  
            new fvMesh                                                          
            (                                                                   
                IOobject                                                        
                (                                                               
                    fluidNames[i],                                              
                    runTime.timeName(),                                         
                    runTime,                                                    
                    IOobject::MUST_READ                                         
                )                                                               
            )                                                                   
        );                                                                      
    }

However, it is possible to re-built the solvers for dynamic meshes. As an idea, if we use dynamic meshes, we do have to implement it as follows (this is just the createDynamicMesh.H file.

    Info<< "Create mesh for time = "                                            
        << runTime.timeName() << nl << endl;                                    
                                                                                
    autoPtr<dynamicFvMesh> meshPtr                                              
    (                                                                           
        dynamicFvMesh::New                                                      
        (                                                                       
            IOobject                                                            
            (                                                                   
                dynamicFvMesh::defaultRegion,                                   
                runTime.timeName(),                                             
                runTime,                                                        
                IOobject::MUST_READ                                             
            )                                                                   
        )                                                                       
    );                                                                          
                                                                                
    dynamicFvMesh& mesh = meshPtr();

If you implement the dynamic mesh lib within the solid region, make sure to include the mesh fluxes into the energy equation. Right now, there are no fluxes included.

        fvScalarMatrix hEqn                                                     
        (                                                                       
            fvm::ddt(betav*rho, h)                                              
          - (                                                                   
                thermo.isotropic()                                              
              ? fvm::laplacian(betav*thermo.alpha(), h, "laplacian(alpha,h)")   
              : fvm::laplacian(betav*taniAlpha(), h, "laplacian(alpha,h)")      
            )                            

          + fvm::div(theMeshFluxFieldPhi, h)                                      
          ==                                                                    
            fvOptions(rho, h)                                                   
        );

I guess all information are given. Good luck,
Tobi

[shach934]

Hello Tobi,
I just tried with a simple case and found out the dynamicMesh is not implemented by chtMultiRegionFoam...
Thanks a lot for the instruction, I will try it tomorrow and update it later if it works.

[shach934]

Hi Tobi,
I am trying to implement this solver. However, I have a question about the fluid domain. I want to rotate the solid region, but the solid region is not a regular cylinder, the rotating region I difned is a cyliner, AMI boundary is used. Fluid cannot be totally excluded from the rotating region. So I do need to include the correctPhi for the fluid region too?
Then, if the solver works, the fluid and solid both need a dynamicMeshDict and with the same rotating velocity and coupled surface. Do you think this will work?
Thanks!

Originally Posted by Tobi

Hi,


simple answer. No it is not implemented. The meshes are derived from the fvMesh class and not the dynamic mesh class.

   forAll(fluidNames, i)                                                       
    {                                                                           
        Info<< "Create fluid mesh for region " << fluidNames[i]                 
            << " for time = " << runTime.timeName() << nl << endl;              
                                                                                
        fluidRegions.set                                                        
        (                                                                       
            i,                                                                  
            new fvMesh                                                          
            (                                                                   
                IOobject                                                        
                (                                                               
                    fluidNames[i],                                              
                    runTime.timeName(),                                         
                    runTime,                                                    
                    IOobject::MUST_READ                                         
                )                                                               
            )                                                                   
        );                                                                      
    }

However, it is possible to re-built the solvers for dynamic meshes. As an idea, if we use dynamic meshes, we do have to implement it as follows (this is just the createDynamicMesh.H file.

    Info<< "Create mesh for time = "                                            
        << runTime.timeName() << nl << endl;                                    
                                                                                
    autoPtr<dynamicFvMesh> meshPtr                                              
    (                                                                           
        dynamicFvMesh::New                                                      
        (                                                                       
            IOobject                                                            
            (                                                                   
                dynamicFvMesh::defaultRegion,                                   
                runTime.timeName(),                                             
                runTime,                                                        
                IOobject::MUST_READ                                             
            )                                                                   
        )                                                                       
    );                                                                          
                                                                                
    dynamicFvMesh& mesh = meshPtr();

If you implement the dynamic mesh lib within the solid region, make sure to include the mesh fluxes into the energy equation. Right now, there are no fluxes included.

        fvScalarMatrix hEqn                                                     
        (                                                                       
            fvm::ddt(betav*rho, h)                                              
          - (                                                                   
                thermo.isotropic()                                              
              ? fvm::laplacian(betav*thermo.alpha(), h, "laplacian(alpha,h)")   
              : fvm::laplacian(betav*taniAlpha(), h, "laplacian(alpha,h)")      
            )                            

          + fvm::div(theMeshFluxFieldPhi, h)                                      
          ==                                                                    
            fvOptions(rho, h)                                                   
        );

I guess all information are given. Good luck,
Tobi

[charlliemarshalll]

Thanks. Is there any chtMultiRegionFoam + moving mesh available in the community?

Moving solid + conjugate heat transfer seems not a rare scenario.