Wake Visualization of the LOFTID Model at Mach 10 Using Planar Laser-Induced Fluorescence

An experimental investigation of the hypersonic wake behind the Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) wind tunnel model in a Mach 10 freestream is discussed. Wake visualization was performed using planar laser-induced fluorescence (PLIF) of nitric oxide (NO), which was locally seeded into the wake through the aft body of the model. PLIF measurements are reported at all three of the typical freestream Reynolds numbers of the NASA Langley 31-inch Mach 10 wind tunnel at an [Formula: see text] angle of attack for two different NO seed gas flow rates. At the lowest Reynolds number, additional data are reported at [Formula: see text] and also with the model rolled to [Formula: see text]. Unsteady wake boundaries and large-scale unsteady flow structures were clearly seen in the wake at these test conditions. The upper wake boundary was identified using a custom edge-tracking algorithm. Changing the mass flow rate of the NO seed gas by [Formula: see text] and varying the Reynolds number did not have a significant effect on the average wake boundary, while notable changes in the wake boundary were observed based on the α variation. Data acquired with the model rolled to [Formula: see text] provided insight into sting effects.