1 volVectorField Ur(Ua - Ub);
2 volScalarField magUr(mag(Ur));
4 volScalarField CdaMagUr
6 (24.0*nub/da)*(scalar(1) + 0.15*pow(da*magUr/nub, 0.687))
9 volScalarField CdbMagUr
11 (24.0*nua/db)*(scalar(1) + 0.15*pow(db*magUr/nua, 0.687))
14 volScalarField dragCoef
17 0.75*(beta*rhob*CdaMagUr/da + alpha*rhoa*CdbMagUr/db)
20 volVectorField liftCoeff
22 Cl*(beta*rhob + alpha*rhoa)*(Ur ^ fvc::curl(U))