Analysis of turbulence statistics and thermofluidic characteristics under circular jet impingement

Abstract

Convective heat transfer studies of impinging jets have received considerable attention over the years, due to their high local, and averaged heat transfer coefficients. In the present work, highly resolved Large Eddy Simulations (LES) are carried out for a turbulent impinging round jet with structured meshes of varying resolution, with both radial and axial refinements. The Reynolds number studied is 23000. The height of discharge from the impingement wall is 2 times the jet diameter. A particular focus of the current research is to study the role of turbulent structures in jet impingement heat transfer. Second order turbulence statistics are computed and validated against established experimental work. Preliminary validation work was carried out by Natarajan et al. [8]. The present study is a continuation of this research, the focus now being upon the turbulence statistics. The work also critically examines the effect of Reynolds number, standoff distance and reveals the role of turbulence in enhancing heat transfer rate, by comparing turbulent statistics and the Nusselt number distributions.