THE EFFECT OF AN APPLIED MAGNETIC-FIELD ON NONEQUILIBRIUM PLASMA-FLOWALONG A BIASED FLAT-PLATE

An experimental study was conducted to clarify the control characteris tics of a non-equilibrium plasma boundary layer flow over a biased and water-cooled flat plate in the tube induced by applying a magnetic fi eld. Argon gas was partially ionized by a DC are discharge at low pres sure. The flat plate was set along the direction of flow in the tube, to which the positive and negative voltage could be alternatively bias ed. A mirror-type magnetic field was applied to the plasma boundary la yer flow over the flat plate by two solenoids. The electron temperatur e was increased by applying the magnetic field, but the electron numbe r density increased for the negative bias and decreased for the positi ve bias. Under these conditions, enhancement of the transport properti es of electrons occurred. The heavy-particle temperature was increased and the thermal boundary layer thickness over the flat plate was decr eased by applying the magnetic field, which resulted in an increase in the heat flux into the plate. The visualization study showed that the relative variation of the radiative temperature nearly corresponded t o the electron temperature field in the applied magnetic field. This i mplies that the application of a combined electromagnetic field is an effective method by which to control the flow of a non-equilibrium pla sma boundary layer over a fiat plate.