INVESTIGATION OF THE. EFFECT OF VORTEX GENERATION ON HEAT TRANSFER ENHANCEMENT IN HORIZONTAL CHANNEL FLOW

In this experimental work, a flow field test system was installed to investigate the impact of vortex generators on the flow structure and heat transfer of air flow in a horizontal channel. Three different configurations of vortex generators, a small single delta winglet pair, a large single delta winglet pair, and two delta winglet pairs developed in a V-formation array were fitted vertically on an aluminum plate and tested in a small wind path system of open circuit with horizontal test section of dimensions 70 mm (width) x 35 mm (height) x 1600 mm (length). An axial AC fan was used to.supply the flow of air through the test section. The air flow was cooling the flat plate which had embedded electric heating constructed as a layered structure. Temperature distributions along the heated plate were measured using thermocouples to obtain the Nusselt numbers. The effect of three different attack angles, 15, 30, and 45 of the selected VGs were investigated in this work. The experimental results showed that under the tested Reynolds number of 10145, the presence of vortex generators had considerable effect on temperature distribution, pressure drop and heat transfer augmentation in the channel flow. Compared with the plain channel; the heat transfer rate was enhanced by (31.9%- 51.0%), (30.8%-53.7 %), and (18.2 %-36.2%) while the pressure drop increased by (1.8%-11.0%), (4.5% - 35.4%), and (6.0 %-30.0%) with the small single delta winglet pair, the large single delta winglet pair, and two pairs deployed in a V-formation array, respectively.