Design and wind tunnel test of an axisymmetric inlet for ramjet engine

The design of an axisymmetic and mixed-compressed inlet model for the ramjet operating Mach number Ma=2.5~4.0 was conducted. By using numerical simulations and wind tunnel tests, the inlet performance for the operating Mach number Ma=2.5, 3.0, and 4.0 with the angle of the attack (AOA) α= 0°, 3°, 6° and 8° was obtained. The tests show that with an increase of the flight Mach number, the total pressure recovery coefficient is reduced dramatically, the sub-critical stable operating range is shortened and the mass flow coefficient is increased gradually. In addition, both the total pressure recovery coefficient and the mass flow coefficient tend to drop when increasing the angle of attack. The case of AOA α= 6° and Ma≥3.0 causes the inlet performance to drop by less than 5% and the sub-critical stable operating range to be reduced.