# The meaning of the divergence term

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 December 22, 2014, 11:58 The meaning of the divergence term #1 Senior Member   Robert Sawko Join Date: Mar 2009 Posts: 117 Rep Power: 13 This is a difficult question for me to ask provided I've been using OpenFOAM for some time, but I really wonder what is the real meaning of the divergence term as given by fvm::div(phi, U). Is it a) u \cdot grad(u) b) \nabla \cdot uu^T The reason why I am asking is that I want to have an fvm based Burgers equation for 1D with the flux f(u) = 0.5 u^2 and I don't know whether I should or shouldn't include the 0.5 term. Code:  while (simple.correctNonOrthogonal()) { solve ( fvm::ddt(U) + 0.5 * fvm::div(phi, U) //*0.5? - fvm::laplacian(DT, U) ); } phi = linearInterpolate(U) & mesh.Sf();