- **OpenFOAM Programming & Development**
(*https://www.cfd-online.com/Forums/openfoam-programming-development/*)

- - **Hi,I have a question about momentum equation in interFoam**
(*https://www.cfd-online.com/Forums/openfoam-programming-development/111631-hi-i-have-question-about-momentum-equation-interfoam.html*)

Hi,I have a question about momentum equation in interFoamDear Foamers:
I have read Henrik Rusche's phd thesis.Now i meet a question in the momentum equation of interFoam. Mr. Rusche defined an 'H' operator AH=As-An*phi where 'As' means source vector.Does As include the item like -grad(p)-g*x*grad(rho)...?Or What included in As?Thank you very much！ |

Take a look at the interFoam/UEqn.H:
Code:
` fvVectorMatrix UEqn` fvVectorMatrix UEqn. In the above definition of UEqn, there is no terms corresponding to grad(p) and g*x*grad(rho), so these terms are not included in the H operator in the interFoam solver. Fumiya |

Here's the UEqn.H in of 2.1.1
surfaceScalarField muEff ( "muEff", twoPhaseProperties.muf() + fvc::interpolate(rho*turbulence->nut()) ); fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(rhoPhi, U) - fvm::laplacian(muEff, U) - (fvc::grad(U) & fvc::grad(muEff)) //- fvc::div(muEff*(fvc::interpolate(dev(fvc::grad(U)) ) & mesh.Sf())) ); UEqn.relax(); if (pimple.momentumPredictor()) { solve ( UEqn == fvc::reconstruct ( ( fvc::interpolate(interface.sigmaK())*fvc::snGrad(a lpha1) - ghf*fvc::snGrad(rho) - fvc::snGrad(p_rgh) ) * mesh.magSf() ) ); } The H operator is constructed by : fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(rhoPhi, U) - fvm::laplacian(muEff, U) - (fvc::grad(U) & fvc::grad(muEff)) //- fvc::div(muEff*(fvc::interpolate(dev(fvc::grad(U)) ) & mesh.Sf())) ); Right? |

I think so.
Fumiya |

Hi, the H operator gives which is defined in Hrv thesis for the implicit terms used in the fvVectorMatrix declaration.
Regards. |

All times are GMT -4. The time now is 08:33. |