Formation and evolution of the flow structure of an inclined jet in crossflow

Abstract

Large-eddy simulation (LES) was used to investigate the formation and evolution of the flow structure of a streamwise-inclined 35° turbulent jet in crossflow (JICF). Predictions by LES agree well with the experimental results of Jia et al. (2015). It is shown that the flow patterns vary with the blowing ratio (BR) considerably, based on three-dimensional flow topologies. For BR = 0.5, the hairpin-like vortices behave like the classic counter-rotating vortex pair (CRVP) that dominates in the JICF. By comparison, the ubiquitous CRVP becomes the characteristic feature of the JICF and persists far downstream at BR = 2.0. Coherent structures developing within the nozzle are incepted by the separation at the jet inlet sharp edge and enhance the formation of the CRVP greatly as BR is increased.