Hypersonic Synthetic Environment Test Tunnel (HySETT) Combined With Marshall Enriched Storable Oxidizer (MESO) Combustion Heating

Combustion heating for creating enthalpies needed for hypersonic temperatures is routinely done, albeit accepting the exhaust products like water vapor, carbon dioxide or soot. Sometimes condensing moisture causes problems in a hypersonic tunnel at desired Mach numbers. Current work funded by the United States Army Space and Missile Defense Command’s (SMDC) Technical Center has resulted in the Hypersonic Synthetic Environment Test Tunnel (HySETT) program, where clean, non-vitiated hot synthetic air is achieved by completely decomposing nitrous oxide into pure oxygen and nitrogen. Then, taking advantage of the generated enthalpy and the minimally produced nitric oxide, thermal modulation from the mixing of nitrogen is conducted to both create the correct air species and meet free stream flight similitude conditions. Hypersonic air, free from moisture and other combustion products, can be created up to about Mach 6 in HySETT. For enthalpies corresponding to higher Mach temperatures, combustion air heating (CAH) by the combination of the Marshall Enriched Storable Oxidizer (MESO) has been analyzed. A particular use case is analyzing the environments being generated in the Arnold Engineering Development Center’s (AEDC) Aerodynamic and Propulsion Test Unit (APTU), where CAH is being conducted with isobutane and liquid oxygen added to replenish the consumed oxygen. Acknowledging that water vapor created for APTU via CAH with this method will need to be recognized, it is the purpose of this paper to discuss alternate CAH testing scenarios created with an approach using the oxidizer propellant MESO.