NONLINEAR CONVECTIVE HEAT TRANSFER IN A TRANSITIONAL PLASMA PLUMEb

Abstract

ABSTRACT: In the paper the results of experimental investigation of wave‐like heat transfer events taking place in the core of transitional plasma plumes are presented and discussed. In order to amplify the dynamic events governing them the arc heater operating conditions were chosen in such a manner that the strong feedback in the plasma column predominated during the nonlinear phase of the transition process. This enabled us to state, that in the events studied the crucial role plays an unstable plume shear layer vortex system inducing the oscillations of the whole plasma column. And just the coupling of them with a mode of organ pipe acoustical oscillations in the arc chamber cavity results in self sustained oscillations of the column and in strong linkage between the thermal events taking place in the plume and the arc chamber cavity. However, the results gained allow us not only to grasp the mechanism of the heat transfer process in the plume core during the transition to turbulence but also provide a means for formulating a conceptual model (scenario) of its evolution. And on the basis of this piece of knowledge a theoretical approach based on the methods of the nonlinear dynamics theory is proposed.