Numerical Analysis of Turbulent Flow and Heat Transfer from Pulsating Impinging Jet to Concave Surface

This paper discusses about the effects of square wave pulsation on the turbulent flow and heat transfer from slot jet impinging to a concave surface. The RNG k-ε turbulence model is applied for modeling the turbulent flow and heat transfer filed in the present 2-D slot jet flow. The effects of jet Reynolds number، nozzle to surface distance and pulsation frequency on time-averaged Nusselt number distribution are studied carefully. Results show that applying the pulsating jet in the range of 10 Hz to 50 Hz can increase heat transfer from the concave surface in comparison with the steady jet. Increasing jet Reynolds number ranged from 4740 to 9590 significantly increases the time-averaged local Nusselt number. Also، in steady jet، decreasing the nozzle to surface distance، consequences increasing the Nusselt number near the impingement zone. While in pulsating jet، it causes both increasing/ decreasing the Nusselt number all over the concave surface.