DOI: 10.1615/ICHMT.2006.TurbulHeatMassTransf
ISBN Print: 978-1-56700-229-4
ISSN: 2377-2816
An LES insight into the flow structure and heat transfer in a round impinging jet
摘要
Large-eddy simulations of a round impinging jet have been performed aimed at gaining a better insight into flow and turbulence structure and their imprints on the heated target wall. The Reynolds number Re = 20000 and the orifice-to-plate distance H/D = 2, where D is the jet-orifice diameter, were chosen to match the experiments of Baughn and Shimizu [1] (also Cooper et al. [4], and Geers et al. [5]). The simulations, performed with the in-house unstructured finite-volume code T-FlowS, confirmed the experimentally detected double peaks in the Nusselt number and the negative production of turbulence energy in the stagnation region. The LES revealed also some other phenomena such as a strong jet flapping around the stagnation point and the unsteady flow separation at the onset of the wall-jet formation. These events seem to be the main cause of the Nu-number nonuniformity, and are linked to the break-up of the shear-layer-generated ring vortices prior or after their impingement.