[sinhavivekananda318]

Hello all,

I am trying to add basicKinematicCollidingCloud to interFoam to see the effect of particles in a bubble rise case. To do so I have added basicKinematicCollidingCloud in the interFoam framewrork in the following way.

1. In the interFoam.C file I have #include "basicKinematicCollidingCloud.H" as a header file.
2. After the pimple loop I have added mu = mixture.mu(); to calculate the dynmaic viscosity of the mixtutre ( I have also declared volScalarField mu in the createFields.H)
3. ///// add particle cloud evolve function
Info<< "\nEvolving " << kinematicCloud.name() << endl;
kinematicCloud.evolve();
This is added before runTime.write().
4. In the createFields rhoInf is defined
5. In the UEqn.H file I have added the particle momentum source as:
fvVectorMatrix UEqn
(
fvm::ddt(rho, U) + fvm::div(rhoPhi, U)
+ MRF.DDt(rho, U)
+ turbulence->divDevRhoReff(rho, U)
==
fvOptions(rho, U)

+ invrhoInf*kinematicCloud.SU(U)// add particle momentum
);
The solver compiled without error, however, when I was running my case, there is a dimension mismatch error stating that :
U[1 -2 2 0 0 0...]+U[0 -2 2 0 0 ...] cant be added due to different dimensions.
To overcome this I removed the multiplicayion by rhoInf to the kinematicCloud.SU(U) and recompiled the solver. Now the code looked like:fvVectorMatrix UEqn
(
fvm::ddt(rho, U) + fvm::div(rhoPhi, U)
+ MRF.DDt(rho, U)
+ turbulence->divDevRhoReff(rho, U)
==
fvOptions(rho, U)

+ kinematicCloud.SU(U)// removed the multiplication by rhoInf
);

Now I recompiled it and my case ran nicely. I could saw the particles experience gravity and gravity as it should, but when I just wanted to inject only the particles with a certain velocity, the particles do not move. Onle when I let particles inject from the outlet in negative Z-dir. they were injected by the force of gravity.

I understand that it might be due to the ommission of the multiplcation by rhoInf to the kinematicCloud.SU(U) which is why the particles dont have momentum.
Then I examined, the p_rgh file where the unit of pressure is [1 -1 -2 0 0 0..]. And this lagragian basicKinemticCloud worked in a separate solver where I merged pimpleFoam with basiCKinematicCloud where the pressure file (p file) have a unit of [0 2 -2 0 0 ...] which is pressure normalised by density.

Now I tried to change the unit in the p_rgh file to [0 2 -2 0 0 ..] which is the unit of p/rho. In this case I got the error that in the calculation of gh equation there is a mistmatch in the dimensions which is understandabe because, p_rgh and rgh both shoud have the dimensions of the real pressure which is [1 -1 -2 0 0 0..].

Now, there are two thoughts coming into my mind .
a) may the basicKinematicCollidingCloud addition will not work in the interFoam
b) I am not getting the right way to add the particle momentum source

I f you could help me regarding this, It would be really helpful.

Regards
Vivek