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Comparison research of two different improved methods in the 2D hypersonic inlet’s design

The article mainly employed the numerical simulation method to conduct the 2D hypersonic inlet performance research. In this study, the numerical simulation method that includes a two-equation turbulence model was validated through the test case firstly. For the purpose of oppressing unstart phenomena, extending operating range and improving comprehensive performance of the inlet, the bleeding system and isentropic expansion arc surface were applied to the inlet, respectively. Different kinds of configurations were designed through changing the length of the bleeding or changing the radius of the arc surface. The influence of the bleeding and isentropic expansion arc surface on the 2D hypersonic inlet was analyzed systematically based on different objective parameters. The calculative results show that the bleeding system with appropriate value of the length can improve comprehensive performance of hypersonic inlet remarkably either on the design point or the off-design points, though it has a very small negative impact on the inlet in terms of the mass flow ratio coefficient. As for isentropic expansion arc surface, it can improve the inlet’s performance at the design point on the conditions that the radius of isentropic expansion arc surface has an appropriate value. But it has much more disadvantages over the basic configuration reversely when it comes to the off-design conditions or the large size of the radius of isentropic expansion arc surface.