{ volScalarField divPhi ( "divPhi", fvc::div(phi) ); // Momentum equation fvVectorMatrix UEqn ( fvm::div(phi, U) + turbulence->divDevReff(U) ); rAU = 1.0/UEqn.A(); // Insert the additional components. Note this will destroy the H and A UEqn += fvm::SuSp(-divPhi, U) + divPhi*U; UEqn.relax(); UpEqn.insertEquation(0, UEqn); }