Numerical simulation of large arrays of impinging jets on a flat surface

Abstract

The objective of the present research is the prediction of large arrays of impingement jets using a computational model. The heat transfer and the force coefficient from single and multiple jet rows (1, 2, 4, 8, and infinity rows) for two different nozzle shapes as either orifice or straight pipe on a fixed flat surface were numerically investigated for drying applications to understand the physical mechanisms which affect the uniformity of the local heat transfer and pressure force coefficient as well as average heat transfer coefficient. The pipe has always a higher averaged Nu and pressure force coefficient compared to the orifice nozzle. Increasing the nozzle to surface distance and decreasing the jet impingement angle reduces the heat transfer and pressure force coefficient. The local Nu number curves for multiple jet rows exhibited many different shapes because of different interference intensities between adjacent jets and also the magnitude of cross-flow. The impact of multiple jet rows on averaged Nu number and jet force coefficient was negligible compared to the single jet row.