A LINEAR-STABILITY ANALYSIS OF A MIXED CONVECTION PLUME FROM A LINE SOURCE - HIGHER-ORDER EFFECTS

Aiding mixed convection flow resulting from the vertical flow of a uniform stream past a horizontal line source of heat is of importance in many practical situations such as hot-wire anemometry. etc. In this paper, the stability of such a flow to small disturbances is analyzed in terms of the linear stability theory. The analysis treats the presence of the free stream as a perturbation of a natural convection plume generated by the line source of heat. The base flow as well as the disturbance field are determined by means of a systematic perturbation expansion. The results presented here extend the results of an earlier investigation [1], by considering second-order mixed convection effects. The results reveal that the free stream has a stabilizing effect. As expected, consideration of second-order mixed convection effects further enhances the stability of the flow. The reported results are valid at a large distance from the source where the flow field is dominated by buoyancy effects.