Heat transfer enhancement on the flat plate by using pulsating jet

In this study, the effect of a pulsating jet on the heat transfer of flow over a flat plate is investigated experimentally and numerically. The experimental study is consist of a copper flat plate having constant heat flux located in the wind tunnel, and including a pulsating jet injected into the stream by the entrance of plate. In the investigations, the blowing ratio, the pulsating frequency and pulsating amplitude are changed while the geometry and Prandtl number remain constant for all cases, and the effect of these parameters on heat transfer is analyzed. The experiments are performed at six different frequencies and four different amplitudes for four different blowing ratios. The problem is also investigated numerically by using the Fluent package programme. In order to explain the heat transfer mechanism, instantaneous velocity and temperature profiles are obtained. The numerical results reveal that there is a disruptive effect on the hydrodynamic boundary layer of pulsating jet, which improves the heat transfer. The obtained results are given as dimensionless parameters. It is observed that, the heat transfer enhancement increases with increasing both Womersley number (Wo) and dimensionless amplitude (Ao) at the high blowing ratio. The numerical results are compared with experiments for different jet parameters, and good agreement between experimental and numerical results is obtained.