HEAT TRANSFER AND FLUID FLOW INVESTIGATION OVER RIB TURBULATORS AND MATRIX STRUCRURES

Abstract

The present work is the fluid flow visualization and heat transfer investigation over different geometries of rib turbulators and matrix structure inside a rectangular duct of wind tunnel at different Reynolds numbers. Various rib turbulator geometries such as triangular, rectangular, trapezoidal, permeable etc. have been used earlier to investigate the heat transfer and fluid flow characteristics for enhancing the heat transfer due to its vast industrial applications. In this study different rib shapes namely, (1) Square, (2) 50, 100 and 15° tapered ribs of square cross-section, along its width and (3) tapered ribs of 3/4, half and 1/4 height of rib at the end along its length are used to investigate the heat transfer from the surface, the taper is given from top middle of rib in both cases. The Liquid crystal thermography technique is used to investigate the heat transfer effect on the surfaces with these ribs. Whereas, smoke is used to visualize the flow patterns over these rib shapes. The heat transfer investigation has been carried out at four Reynolds numbers of 2050, 4100, 6150 and 8200. Flow patterns are visualized at Reynolds number of 8200 These Reynolds number calculated on the basis of rib height. The investigation of heat transfer and flow visualization has been investigated in different wind tunnel. A correlation between heat transfer and flow visualization results has been established. Further, the study has been carried out for heat transfer investigation inside a matrix channel. The experiment has been conducted at three Reynolds numbers of 9400, 19600 and 26160, which are calculated on the basis of hydraulic diameter of duct.