Hypersonic flows in large-scale inlet models.

Analytical and experimental investigations were conducted to determine the characteristics of the internal flows in model passages representative of inlets for a typical Mach 12 hypersonic cruise vehicle and also sufficiently large for reliable data to be obtained. Three large-scale inlet models, each having a different internal compression ratio, were designed to provide maximum performance at the throat stations. Tests were conducted in the Mach 7.4 nozzle of the NASA Ames 3.5-foot hypersonic wind tunnel at a nominal test Reynolds number of 2,700,000 per ft. The experimental results revealed that a high level of total pressure recovery, approximately 0.85 (relative to the inlet-entrance conditions) for the core flow of the internal passage, was achieved for each inlet design.