Numerical investigation of flow and heat transfer characteristics of circular pulsated impinging jet

The objective of this work is to numerically investigate the influence of Reynolds number, alternation amplitude and frequency on flow and heat transfer characteristics of a fluctuating circular air jet, impinging on a smooth and flat disc. Using control volume method and SIMPLE algorithm, a computer program has been developed for this investigation. Simulations are done for Reynolds number 300, 500 and 700 and oscillation amplitude and frequency are assumed to range 0.0V0~0.8V0 (m/s) and 1~6 (Hz), respectively where the mean velocity of the jet is function of the Reynolds number. The velocity at the nozzle exit varies periodically as function v_in=v_0+Av_0 ?(t). Using the temprature distribution obtained as simulation results, the local Nusselt number, stagnation point Nusselt number and time-averaged stagnation point Nusselt number on the target plate are calculated. It?s concluded that the Nusselt number rises with increasing Reynolds number. Any certain trend of frequency and amplitude effects on Nusselt number values has not been achieved for low Reynolds numbers. Increase of frequency and amplitude leads to a Nusselt number enhancement in the case of Reynolds number 700.