Flow structure of pitched and skewed microjet vortex generator array

Abstract

To understand the micro-vortex structure of Microjet Vortex Generators, a plate with pitched and skewed jet holes was established. Simulations using SST-DDES method based on WENO scheme were conducted to analyse the effect of jet pressure, hole interval and incoming boundary layer thickness on the flow structure. The pitch angle and skew angle are 55 degrees and 45 degrees respectively. The total pressure of microjets ranges from 2.5 to 3.5 times the mainstream pressure. The interval of microjets ranges from 6.75 to 13.5 diameters of the hole, and the thickness of incoming boundary layer ranges from 2 to 4 diameters of the hole. The flow field is dominated by three vortices, including a main vortex and two secondary vortices which are significantly influenced by jet pressure and interval. The interaction between secondary vortices and main vortex plays an important role in the process of boundary layer mixing.