Sod shock tube problem
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Solve the ideal gas equations in 1D, starting with a single
discontinuity. Common test of the accuracy of shock-capturing schemes

Sod, G. A. (1978) J. Comput. Phys. 27: 1-31. doi:10.1016/0021-9991(78)90023-2.


Starting conditions are

Left: rho = 1, p = 1, v = 0
Right: rho = 0.125, p = 0.1, v = 0

