دراســــة عمليـــة لـمدى فاعليــة الدوامـــات في التبـــادل الحـــراري بـين الموائـــع

Abstract

In this research, the vortices are used in the heat exchange between fluids, relying on previous studies which indicated that the vortex flow causes a sharp increase in the heat transfer rate. This means that the area needed for heat exchange surface is in this case smaller than that of the non-vortex flow. Hence, a heat exchanger is constructed from three smooth concentric cylinders of different size, the inner of which is rotatable, whereas the others are fixed. On the other hand, the inner and the outer cylinders are adiabatic whereas the middle cylinder which corresponds to the fluids heat exchange surface is made of very high thermal conductivity metal as the Aluminum.Water and air are used here as the heat exchange fluids .A Taylor vortex flow is induced in the hot water at (80˚C) occupying the annulus between the inner and the middle cylinders by rotating the inner cylinder to or above a certain speed limit of 65 RPM which corresponds to the critical Taylor number of 1.162E4, as the inner cylinder speed was varied from 0 to 80 RPM. Mean while, a swirl is generated in the cold air (at room temperature) within the annulus between the middle and the outer ......