Numerical investigation of single and multiple impinging synthetic jets on the flow field and heat transfer at low orifice-to-plate distances

In the present numerical study, the thermal performance and fluid flow properties have been investigated to show the effect of single-orifice and multiple-orifice impingement of synthetic jets for dimensionless orifice-toplate distance (H/D) of lower than one. Investigations have been done for an actuation frequency of f=500 Hz, 0.10 ≤ H/D ≤ 0.75, and dimensionless pitch ratio of 1.25 ≤ Do/D ≤ 1.75. The results were validated with experimental results from the literature, and a fair agreement was obtained. The results showed that at low nozzle-to-plate spacing, lower target plate temperatures could be obtained. It was observed that with the use of multiple orifices at especially higher Do/D higher heat transfer values are present. The study was performed to add knowledge to the electronics and aviation industries where high temperatures in small cavities occur.