Implementation of the flowmodulated skewupwind difference scheme in the COMMIX1C code: A first assessment
Abstract
The implementation of the FlowModulated SkewUpwind Difference (FMSUD) scheme in the momentum equation of the COMMIX1C computer program, where the scheme has been used so far only in the energy equation, is described in detail. Because the three scalar components of the momentum equation are solved in different meshes, staggered with respect to the mesh used for the energy equation and displaced in the respective coordinate direction, implementation of the FMSUD scheme in the momentum equations is by far more demanding than the implementation of a single scalar equation in centered cells. For this reason, a new approach has been devised to treat the problem, from the mathematical viewpoint, in the maximum generality and for all flow conditions, taking into account automatically the direction of the velocity vector and thus choosing automatically the weighting factors to be associated to different cells in the skewupwind discretization. The new mathematical approach is straightforward for the treatment of inner cells of the fluiddynamic definition domain, but particular care must be paid to its implementation for boundary cells where the appropriate boundary conditions must be applied. The tests cases are explained in which the implementation of the FMSUD method has been applied and the quality of the numerical results against the correct solution, when the latter is known, is explained.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 1991
 Bibcode:
 1991STIN...9126489B
 Keywords:

 Computation;
 Computer Programs;
 Difference Equations;
 Finite Difference Theory;
 Fluid Mechanics;
 Free Convection;
 Skewness;
 Diffusion;
 Isotherms;
 Regulations;
 Velocity;
 Fluid Mechanics and Heat Transfer