reactingTwoPhaseEulerFoam: Added mass-exchange contribution to the cell-based momentum equations

applications/solvers/multiphase/reactingTwoPhaseEulerFoam/pU/UEqns.H

@@ -11,11 +11,15 @@ volScalarField Kd(fluid.Kd());
 {
     volScalarField Vm(fluid.Vm());
 
+    const volScalarField dmdt12(fluid.dmdt()*pos(fluid.dmdt()));
+    const volScalarField dmdt21(fluid.dmdt()*neg(fluid.dmdt()));
+
     {
         U1Eqn =
         (
             fvm::ddt(alpha1, rho1, U1) + fvm::div(alphaRhoPhi1, U1)
-          - fvm::Sp(phase1.continuityError(), U1)
+          - fvm::Sp(phase1.continuityError() - dmdt21, U1)
+          - dmdt21*U2
           + MRF.DDt(alpha1*rho1, U1)
           + phase1.turbulence().divDevRhoReff(U1)
          ==
@@ -40,7 +44,8 @@ volScalarField Kd(fluid.Kd());
         U2Eqn =
         (
             fvm::ddt(alpha2, rho2, U2) + fvm::div(alphaRhoPhi2, U2)
-          - fvm::Sp(phase2.continuityError(), U2)
+          - fvm::Sp(phase2.continuityError() + dmdt12, U2)
+          + dmdt12*U1
           + MRF.DDt(alpha2*rho2, U2)
           + phase2.turbulence().divDevRhoReff(U2)
          ==