imogenproject / gpuImogen

Codeveloped version of the Imogen code that runs on the GPU
http://imogenproject.org
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Locate fatal problem with magnetosonic advection #37

Open ekeever1 opened 10 years ago

ekeever1 commented 10 years ago

Fast magnetosonic waves under the default test conditions (v = 0, Pgas = rho = 1, B = [.5 .3 0]) exhibit a resolution independent error, falling behind by .17 radians per cycle from nominal.

The error is not constant but "wobbles", indicating the simulation is not running a pure MS wave. There is also harmonic distortion at all harmonics, where sonic waves show exactly zero HD at (one of even/odd, don't remember which) harmonics, down to machine precision.

This is a "code not acceptable, FULL STOP" error. Absolutely no production MHD work can be done until it is hunted down, wounded, cornered and killed with an elephant gun.