Facility opportunities and associated stream chemistry considerations for hypersonic air-breathing propulsion

Ground test requirements for the hypersonic air-breathing propulsion systems and the related facilities are examined. Emphasis is given to issues of stream chemistry in propulsion facilities and simulation requirements at the upper hypersonic-hypervelocity range approaching orbital speed. It is concluded that only the free piston-driven expansion tunnel offers a near-term opportunity to achieve the total pressures required for direct connect and freejet engine tests out to orbital speeds. (AIAA)