A NONLINEAR, SUBGRIDSCALE MODEL FOR INCOMPRESSIBLE VISCOUS-FLOW PROBLEMS

We consider a nonlinear subgridscale model of the Navier-Stokes equati ons resulting in a Ladyzhenskaya-type system. The difference is that t he power ''p'' and scaling coefficient mu(h) = O(h(sigma)) do not aris e from macroscopic fluid properties and can be picked to ensure both L (infinity)-stability and yet be of the order of the basic discretizati on error in smooth regions. With a properly scaled p-laplacian-type ar tificial viscosity one can construct a higher-order method which is ju st as stable as first-order upwind methods.