Orzang-tang Vortex

The initial conditions for an ideal gas with γ = 5/3 are constructed within a unit-length domain (e.g. x = [0, 1], y = [0, 1]) with periodic boundary conditions. The velocity field is defined by vx = −sin(2πy) and vy = sin(2πx). The initial magnetic field is set to be Bx = B0 vx and By = B0 sin(4πx). The initial density is ρ = γ P and the pressure is set to P = γ B0**2 . B0= 1/(4*pi)