which formula used in drag force in dragModel.C?

qi.yang@polimi.it · August 12, 2020, 06:14

Hi, everyone. I am confused that the expression of drag force used in Openfoam, as shown in the following codes. Why there is nu and divided by square of particle diameter. I saw the formula is without nu and only divided by diameter in some literature. Do you have any tip for me? Thanks a lot. By the way, After I deleted pair_.continuous().nu() and only divided by diameter. The results I obtained are totally the same.

Foam::tmp<Foam::volScalarField> Foam::dragModel::Ki() const
{
return
0.75
*CdRe()
*swarmCorrection_->Cs()
*pair_.continuous().rho()
*pair_.continuous().nu()
/sqr(pair_.dispersed().d());
}

qi.yang@polimi.it · August 12, 2020, 08:28

I understood the formula because CdRe already multiplied by a Re, so it should time nu and divide the other diameter in dragModel.C.

August 12, 2020, 06:14	which formula used in drag force in dragModel.C?	#1
qi.yang@polimi.it Senior Member kimy Join Date: Mar 2019 Location: https://t.me/pump_upp Posts: 164 Rep Power: 6	Hi, everyone. I am confused that the expression of drag force used in Openfoam, as shown in the following codes. Why there is nu and divided by square of particle diameter. I saw the formula is without nu and only divided by diameter in some literature. Do you have any tip for me? Thanks a lot. By the way, After I deleted pair_.continuous().nu() and only divided by diameter. The results I obtained are totally the same. Foam::tmp<Foam::volScalarField> Foam::dragModel::Ki() const { return 0.75 CdRe() swarmCorrection_->Cs() pair_.continuous().rho() pair_.continuous().nu() /sqr(pair_.dispersed().d()); }

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August 12, 2020, 08:28		#2
qi.yang@polimi.it Senior Member kimy Join Date: Mar 2019 Location: https://t.me/pump_upp Posts: 164 Rep Power: 6	I understood the formula because CdRe already multiplied by a Re, so it should time nu and divide the other diameter in dragModel.C.