Normal Shock/Boundary-Layer Interaction Control Using Sub-Boundary-Layer Vortex Generators

Experiments are conducted at an inflow Mach number of 1.6 to control a normal shock-induced separation using sub-boundary-layer vortex generators (SBVGs). A steady normal shock is located in the test section using a dual-channel working section arrangement and a variable tunnel second throat. An array of three SBVG configurations, namely, delta ramp, ramp vanes, and rectangular vanes, are tested ahead of the interaction for separation locations of [Formula: see text], 0.46, and 0.51. For all devices, a maximum reduction of 34% in separation is seen for [Formula: see text] with a reduction in [Formula: see text]-shock benefit and a fuller profile close to the near-wall region. Separation control capability, however, becomes more distinct with increasing control distance. At [Formula: see text], a ramp-vane device of height 0.2[Formula: see text] shows enhanced pressure recovery by 1% relative to no control with reasonably good separation control (17%) as well. In terms of separation shock unsteadiness, the peak rms value at [Formula: see text] is the lowest for ramp-vane devices with [Formula: see text]. The current approach of resizing vane chord length and rearranging the SBVGs in the array not only helps to confine separation closer to the near-wall region but also keeps their separation control capability reasonably unaltered with improved pressure recovery.