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danieljprice / phantom

Phantom Smoothed Particle Hydrodynamics and Magnetohydrodynamics code
https://phantomsph.github.io
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Signal speed used in tcour should include radiation pressure #474

Closed themikelau closed 10 months ago

themikelau commented 11 months ago

Add contribution of radiation pressure to signal speed when using radiation (e.g., Eq 10 in https://arxiv.org/abs/1102.1216). We should have cs = (5/3Pgas/rho + 4/3Prad/rho)^1/2. Otherwise, tcour may be underestimated.

danieljprice commented 11 months ago

this is a good idea, however we should test before merging as it would also increase the shock viscosity. Best problem for this would be the radiation shock tube (radshock) although we'd need to do it in a regime where radiation pressure is significant to see what difference this makes to the shock capturing (and indeed the stability)