Stability study for the MHD problem in perforated and parallel walls

摘要

We have studied the stability of a conducting fluid when it is continuously injected or ejected through a pair of parallel porous walls and escapes in both directions along the channel. The flow forms a stagnation point at the center and the effluence is restricted by a magnetic field perpendicular to the walls. A theoretical analysis of the steady state solutions of the MHD equations in the incompressible case is given as a function of three parameters R_e, R_m and M_A (R_e: Reynolds number, R_m: magnetic Reynolds number, M_A: Alfvenic Mach number), for some asymptotic limits. In the case of suction, critical values of the parameters are found for which there are bifurcations in the system. Such bifurcations are pitchfork type. In the case of injection, the flux results always stable.