Numerical study of flow and temperature field due oscillating impinging jet on the dimpled surface

Impingement jet is a fluid flow that hits a surface perpendicularly or at a specific angle for the purpose of cooling or heating. The rate of transfer processes in turbulent impingement flows is affected by the formation of coherent structures, the interaction between them and transfer of It's energy.By oscillating the incoming flow in the impinging jets, the formation of coherent structures can be affected, and as a result, the amount of heat removal is affected. In this study, the effect of pulsed impinging jet using step and sinusoidal functions The flow and temperature field of a dimpled surface has been investigated by numerical method. The key parameters in this study include the shape of the input function, the frequency and the amplitude of the oscillating jet. The results of this study have been validated using previous researches and then The effect of key parameters on the  formation of coherent structures and the amount of heat extraction have been discussed and analyzed. The results show that bypulsating the inlet flow, it is possible to change the recirculation zones and the vorticity field in the flow and overally The heat increases on the dimpled surface. Such results show that the flow patterns and Nusselt number are highly dependent on the parameters of the input function such as frequency and amplitude.