Effect of impinging distance for convective heat transfer of synthetic jet

Numerical simulations and experimental methods are conducted to discover the effect of various distance between the orifice and the heated plated (L). The investigation focusing on the characteristics of convective heat transfer by a synthetic jet circular orifice. The results is verified by the time history of convective heat transfer characteristic and validated against existing experimental results. The model was simulated to investigate the dispersion of heat flow on the walls using a mathematical turbulent model of k-w SST. The Reynolds number (Re) is in the range of 1421-2843 based on average velocity, while the normalized impinging distance varies between 0 and 3.3. The movement of the piezoelectric membrane is assumed of sinusoidal wave function. The results showed the significant influence of L/d Ratio and sinusoidal wave frequencies to the heat transfer rate obtained. At small axial distance (L), average Nusselts number decrease due to confinement effect. However, at larger axial distances, the synthetic jet velocity weaken which again reduces the convective heat transfer coefficient.