Design Methodology And Flow Characteristic Of Two-Dimensional Hypersonic Aircraft Forebody/Inlet

Two-dimensional hypersonic forebody/inlet integration design methods was investigated through numerical simulation in this paper. Three kinds of forebody/inlet design methods including conic section based, the streamline tracing and waverider-wedge combination were used to design the geometry of this two-dimensional hypersonic forebody/inlet. And the impact of relevant geometric control variables on the aerodynamic performance of these geometries was analyzed through three-dimensional numerical simulation.Firstly, a two-dimensional forebody/inlet configuration was designed and its performance was investigated by two-dimensional numerical simulation. The result shows that: at different inflow Mach number Ma? and flight attack angle ?, the inlet flow path don't not have large flow separation; as the increase of inflow Mach number and flight attack angle, static pressure ratio, mass flow coefficient of forebody/inlet increased gradually, but the total pressure recovery coefficient decreased.Secondly, based on the forebody/inlet two-dimensional profile, the transverse section of forebody was designed by the conic section in the form of secondary rational Bezier line and the impact of different geometric control variables on the aerodynamic performance of forebody/inlet was investigated by three-dimensional numerical simulation. The result shows that: within the scope of the study, increasing width ratio W₁/W₀, shape parameter ?_CD and horizontal control curve number n, decreasing the angle ?_DG, angle ?_CG, can reduce the lateral pressure gradient of forebody, reduce lateral overflow, and improve the internal flow performance of forebody/inlet; Increasing angle ?_CF, decreasing the shape parameter ?_BC can reduce drag, increase the lift, and improve the lift-to-drag ratio. On this basis, a forebody/inlet aerodynamic design program combining the constraint of realizable forebody was given. The three-dimensional numerical simulation analysis shows that: at different inflow Mach number Ma?, the difference compared with the two-dimensional flow of the static pressure ratio, total pressure recovery coefficient and mass flow coefficient are within-5% 10%; At flight attack angle ?, the difference compared with the two-dimensional flow of the static pressure ratio, total pressure recovery coefficient and mass flow coefficient are within-5% 15%.Thirdly, on the basis of the same forebody/inlet two-dimensional profile, a thought of waverider forebody/inlet based on streamline tracing was given, and the impact of the forebody width ratio W₁/W₀, angle ?, upper and lower surface control curve number n_up and n_down on the aerodynamic performance of forebody/inlet was investigated by three-dimensional numerical simulation. The result shows that: compared with forebody configuration based on the conic section, the external compression shock wave on the first stage compression section of the configuration is almost attached, and the lateral pressure gradient in the inlet inside flow path is small, and the lateral pressure gradient in the second and third compression section is close to zero, and the drag is low, and lift-to-drag is relatively high; Increasing W₁/W₀, angle ? and upper surface control curve number n_up, and reducing lower surface control curve number n_down, can reduce the lateral foerbody pressure gradient, reduce the lateral overflow, and improve the aerodynamic performance of the inlet.Finally, based on a kind of waverider forebody aerodynamic design program, several waverider-wedge combination design programs of forebody/inlet were built, along the coming flow direction straight cutting and ladder cutting, and the analysis about them were carried out by three-dimensional numerical simulation. The result shows that: when the straight cutting and ladder cutting on foerbody two sides is behind the Mach cones position corresponded to inlet sidewall, the external compression shock wave of forebody within the scope of the inlet inside path width almost unchanges and matches better with rectangular entrance of inlet; Straight cutting and ladder cutting only have a little effect on aerodynamic performance of internal flow of inlet, and can reduce the drag coefficient, lift coefficient and lift-drag ratio of forebody/inlet, and improve the total pressure recovery coefficient; Compared with ladder cutting, the drag coefficient and the total pressure recovery coefficient of straight cutting are relatively small, and the lift coefficient and lift-drag ratio are relatively large.