Multigrid method for LaxWendroff scheme
Hi everyone,
I am working with an inhouse compressible NavierStokes solver which uses the onestep second order Ni's laxWendroff scheme. For accelerating the convergence, I am trying to implement the multigrid in the solver. Actually, in LaxWendroff method, because of the coupled descreatization of time and space, the algorithm is a little bit different from explicit multistage codes. It is actually called "multiplegrid" in Ni's first paper. I just wanted to find out whether anybody have any experience or information about it because it does not seem to be working in my code. I know this topic has been closed almost 30 years ago and that makes it even more difficult because I can not find anybody alive in the authors to contact. Thanks. 
You can write you discretization in semidiscrete form (discretize only over space, not time). This is greatly preferable from a software perspective since you can use any SSP method for the forward integrator, and can naturally solve for steady states. Once you have a semidiscrete form, you can use pseudotransient continuation (http://www.cs.odu.edu/~keyes/papers/ptc03.pdf) in NewtonKrylov or nonlinear multigrid form to solve for steady state.

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