Preliminary test study was conducted for hypersonic inlets with rectangular section at Mach number of 6

5 and 4 in a high enthalpy wind tunnel.The inlet could be started within the range of the Mach number 4.5 and 6.5.The performance and static-pressure distributions of the inlet under different back-pressure conditions were obtained.Results indicate that

at design condition(Ma=6

α=0°)

the mass flow capture rate and mass-averaged total pressure recovery coefficient are 0.97 and 0.41

respectively;at the exit section of the isolator

the average Mach number is less than 2.6

the pressure rise and maximum back-pressure are 35 and 141.52 times of upstream pressure.The shock train formed by back-pressure rising can be kept in the inner tunnel

without affecting the mass flow capture rate.The mass flow capture rate is not less than 0.77

and the mass-averaged total pressure recovery coefficient varies between 0.49 and 0.67 at Mach number of 5 and 0° angle of attack.In the non-back-pressure status

there is no obvious flow separation in the flow inlet field of the inlet.