EXPERIMENTAL AND NUMERICAL STUDY OF HEAT TRANSFER OVER A FINNED ELLIPTICAL FLAT TUBE FITTED WITH LONGITUDINAL VORTEX GENERATORS ON THE RECTANGULAR FIN SURFACE

An experimental study of heat transfer over a finned elliptical flat tube fitted with and without longitudinal vortex generators (LVGs) mounted on the rectangular fins was carried out in a wind channel. Numerical simulation was performed to compare the experimental results and to verify the turbulence model. The test models were magnified four times greater than the original react model and correspondingly simplified according to the principle of similitude. Several fins were designed to construct the periodic boundary condition. Thermo couples were used to measure the temperatures on the fins and tube of the flow and surfaces. The experimental results showed that in the low Reynolds number regime, the heat transfer decreased continually from the entrance along the stream wise direction. However, in the high Reynolds number regime, the heat transfer had a maximum value in the middle points of the fins along the stream wise direction. It was demonstrated through the numerical simulation and experimental results that the configuration of the fin and tube with the LVGs on the fins could attain enhanced heat transfer without too much pressure drop.