1 if(divSigmaExpMethod == "standard")
5 mu*gradU.T() + lambda*(I*tr(gradU)) - (mu + lambda)*gradU,
9 else if(divSigmaExpMethod == "surface")
11 divSigmaExp = fvc::div
13 muf*(mesh.Sf() & fvc::interpolate(gradU.T()))
14 + lambdaf*(mesh.Sf() & I*fvc::interpolate(tr(gradU)))
15 - (muf + lambdaf)*(mesh.Sf() & fvc::interpolate(gradU))
18 else if(divSigmaExpMethod == "decompose")
20 snGradU = fvc::snGrad(U);
22 surfaceTensorField shearGradU =
23 ((I - n*n)&fvc::interpolate(gradU));
25 divSigmaExp = fvc::div
29 - (muf + lambdaf)*(snGradU&(I - n*n))
30 + lambdaf*tr(shearGradU&(I - n*n))*n
35 else if(divSigmaExpMethod == "expLaplacian")
38 - fvc::laplacian(mu + lambda, U, "laplacian(DU,U)")
42 + lambda*(I*tr(gradU)),
48 FatalError << "divSigmaExp method " << divSigmaExpMethod << " not found!" << endl;