Abstract:

A study is carried out on a hypersonic inlet with rectangular-to-circular shape transition and forebody using numerical simulation and high enthalpy wind tunnel test. Results indicate: (1) For the test condition of free stream Mach number 6, the total pressure recovery, pressure ratio and mass flow ratio of the inlet are 0.40, 39.8 and 0.769 respectively with a Mach number of 2.60 at the inlet exit, and at free stream Mach number 5 the total pressure recovery is 0.45, pressure ratio is 19.7, the mass flow ratio is 0.643 and the Mach number at the inlet exit is 2.28; (2) When the outlet of the duct is fully opened, static pressure fluctuates greatly along the top and bottom inner walls; (3) The distortion at the inlet exit is quite high due to the strong lateral pressure gradient in the isolator; (4) The forebody causes more lateral spillage, which may adversely affect the performance of the inlet; (5) The experimental results prove the reliabilities of the method based on CFD.

Key words: aerospace propulsion system, hypersonic inlet, rectangular-to-circular shape transition, forebody