Effective Distance for Vortex Generators in High Subsonic Flows

Abstract

Vortex generators (VGs) are a passive method by which to alleviate boundary layer separation (BLS). The device-induced streamwise vortices propagate downstream. There is then lift-off from the surface and the vortex decays. The effectiveness of VGs depends on their geometrical configuration, spacing, and flow characteristics. In a high-speed flow regime, the VGs must be properly positioned upstream of the BLS region. Measurements using discrete pressure taps and pressure-sensitive paint (PSP) show that there is an increase in the upstream surface pressure and the downstream favorable pressure gradient. The effective distance for a flat plate in the presence of three VG configurations is determined, as is the height of the device (conventional and micro VGs).

Global Surface Pressure Pattern for a Compressible Elliptical Cavity Flow Using Pressure-Sensitive Paint

“…Experimental conditions are shown in Table 1. The boundary layer thickness for a naturally developed turbulent boundary layer, , was approximately 7 mm at a value of M of 0.83 [19]. The Reynolds number based on the boundary layer thickness, Re, was 1.69 × 10 5 .…”