Flow pattern induced by the plane piston moving in a non-ideal gas with weak gravitational field

A systematic perturbation scheme is used to analyze the flow pattern induced by the motion of a plane piston moving with constant velocity in a non-ideal gas with weak gravitational field. The flow variables are expanded as a series of small parameter ε, which is the ratio of the typical escape velocity to the plasma velocity. The zeroth order solution gives the uniform flow which is influenced by the parameter of non-idealness without gravity. The first order relationships show the influence of non-idealness of the gas as well as the applied gravity on the flow field. Distribution of the flow variables has been presented graphically for various values of parameter of non-idealness. The structure of the shock front in case of small perturbation theory is also discussed.