Experimental investigation of the heat transfer characteristics of a pulsating impinging jet on a flat surface

In this research, cooling of the target surface consisting of a flat plate with constant heat flux using a pulsating impinging jet is investigated experimentally. In the investigations, the jet Reynolds number (Rej), Prandtl number (Pr) and geometric parameters were kept constant and the effects of these parameters on the heat transfer were analyzed while changing the distance between the jet and the target surface (H/D), amplitude (Ao) and jet frequency (Wo). Experiments were performed for three different blowing distances, four different amplitudes and six different frequencies. The pulsating jet is used as an active heat transfer enhancement method, temperature measurements were made in detail on the experimental setup and Nusselt numbers were calculated with the based on measured temperatures. The results are expressed as a function of dimensionless numbers, and the results are compared with the heat transfer results of continuous jet impingement. Experimental results showed that the pulsating jet has a significant effect on heat transfer enhancement. It was observed that the pulsating jet significantly increased the heat transfer compared to the continuous jets.