Flow and heat transfer characteristics of inclined rotating impinging jets using DNS

Abstract

Jets are one of the most fundamental flows used in industry, and among them, impinging jets are used in industrial applications such as cooling of gas turbine blades and electronic devices. Because of the high heat and mass transfer coefficients near the stagnation point, impinging jets are used in various fields as a highly efficient means of heating, cooling, drying, and cleaning surfaces. On the other hand, the heat transfer performance of the impinging jet decreases rapidly away from the stagnation region, and it is necessary to increase the heat transfer area by eliminating the non-uniform heat transfer distribution. In previous studies, it has been shown that the bifurcation structure of the jet, which is characteristic of a blooming jet, can be obtained by combining inclination and rotation control of the jet with axial excitation, and that higher mixing performance can be obtained than that of the blooming jet. In this study, direct numerical simulations (DNS) of a inclined rotating impinging jets are conducted to evaluate the changes in flow characteristics and heat transfer performance. As a result, it was found that the controlled jet with inclined and rotational motion was strongly affected by the distance between jet and impinging wall.