# rhoCentralFoam fvSchemes none

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 April 1, 2017, 07:14 rhoCentralFoam fvSchemes none #1 Member   Join Date: Jul 2014 Posts: 39 Rep Power: 12 Hi In shockTube tutorial test case, the divSchemes looks like follows: Code: ```divSchemes { default none; div(tauMC) Gauss linear; }``` And in solver rhoCentralFoam, solving for density: Code: `solve(fvm::ddt(rho) + fvc::div(phi));` My question: what scheme is used to solve for phi? As I understand, if a scheme is not specified, OpenFOAM gives an error and suggests the possible schemes. Thanks Last edited by PicklER; April 1, 2017 at 07:15. Reason: Too general Title

 April 1, 2017, 08:16 #2 New Member   Join Date: Mar 2014 Location: Czech Republic Posts: 29 Rep Power: 14 Hi, look into rhoCentralFoam.C, the solver is based on Kurganov and Tadmor central schemes, ie, Riemann-solver-free approach.

 April 1, 2017, 09:47 #3 Member   Join Date: Jul 2014 Posts: 39 Rep Power: 12 Hi Thank you for the quick reply. I think I understand it now. phi is calculated by the interpolated variables of the cell faces and therefore solved. I noticed that for n number of cells in a straight line, like in the shocktube test case, phi has only n-1 values, which confirms that phi only exists on the faces. And the obvious definition of phi Code: `surfaceScalarField phi("phi", mesh.Sf() & fvc::interpolate(rhoU));` The same is done for the momentum and energy equations. I found a good article on rhoCenralFoam and it explains how the convective terms in the conservation equations are handled: here I am busy writing up my understanding of it in a way I can better explain it. Thanks again Jiss and hogsonik like this.

 Tags fvschemes, rhocentralfoam