ABSTRAKT

In the present study, the effect of a transversely pulsating jet on heat transfer performance over a flat plate is investigated experimentally and numerically. A secondary mass flux by the transverse pulsating jet to the main flow from the front end of the plate with constant heat flux is added. It enhances the heat transfer by placing a periodically changing film layer between the plate and the forced flow on the plate. In the investigations, the Reynolds number in the main stream (or the blowing ratio) and the frequency and amplitude of the pulsating jet are changed while the geometry and Prandtl number remain constant for all cases, and the effect of these parameters on the heat transfer performance is analyzed. The experimental studies are performed at four different blowing ratios for six different frequencies and four different amplitudes, and they are evaluated with respect to heat transfer. In addition, the problem is modeled numerically using control-volume-based commercial code. To explain the heat transfer mechanism, instantaneous velocity and temperature profiles are obtained. The results reveal that the pulsating jet is effective in all plate surfaces and that the heat transfer performance increases with increases in both the Womersley number (W₀) and the dimensionless amplitude (A₀) at a high blowing ratio (M). The obtained results are presented as a function of dimensionless parameters, which are the primary factors affecting the heat performance on the flat plate.