1929 Analysis of Turbulent Structure in Impinging Jets using DNS

Abstract

In order to improve the heat transfer on the wall, impinging jets is used in various industrial applications, and has been investigated experimentally and numerically so far. However, it is not enough to make clear the detail of vortical structure contributing to the heat transfer. In the present paper, DNS (direct numerical simulation) of the impinging jet is conducted to investigate the heat transfer through the different Re number flow. The discretization in space are performed with hybrid scheme in which Fourier spectral and 6th order compact scheme are adopted. From the statistical flow properties, it is demonstrated that depending on the Re number, the thinning of viscous layer induces the enhancement of heat transfer on the wall. In addition, from instantaneous view of flow structures, it is found that not depend on the Re number, the large-scale vortex rings are formed on the wall and contribute to the heat transfer enhancement.