Integrated design of waverider forebody and inward-turning inlet considering viscous effect under given flowfield distribution

The integrated configuration of the waverider forebody and inward turning inlet is one of the mainstream choices for the long-range hypersonic cruise vehicle due to its great high-speed lift-drag characteristics, superior inflow capture ability and high compression efficiency. To improve the performance of the integrated configuration, this paper proposes an integrated design method based on improving the basic flowfield design and considering the viscous effect. In terms of basic flowfield design improvement, the total pressure distribution of the reflected shock wave is improved to a quadratic distribution which can reduce the gradient of the total pressure distribution. After giving the antitangent Mach number distribution on the upper wall and the Bezier flow angle distribution on the center body wall, the high-total-pressure-recovery internal compression basic flowfield with the controllable flow field distribution in the whole flow channel is designed. Compared with the local inverse design basic flowfield with only a given Mach number distribution on the upper wall, the central body of the new basic flowfield becomes a tapered surface, the intensity of the reflected shock wave is greatly reduced, and the total pressure recovery coefficient is greater than 0.98. The resulting integrated configuration maintains the characteristics of the basic flowfield while exhibiting lower strength of the reflected shock wave in the inner contraction section and the shock wave train in the isolation section and the reduced proportion of the low energy region at the exit. Consequently, the lift-to-drag ratio at the design point increase by 15.16%, the total pressure recovery coefficient at exit increase by 3.33%, and the distortion at exit decrease by 4.62%. In terms of the consideration of the viscous effect, this paper combines the high-fidelity numerical solution results with the displacement thickness calculation formula of the axisymmetric boundary layer to carry out the viscosity correction. Compared with the traditional two-dimensional plate boundary layer viscosity correction method, the axisymmetric configuration verification example shows that the proposed method can improve the profile correction accuracy and reduce the deviation from the inviscid design performance target. This method is applied to the viscosity correction of the original configuration to obtain a modified configuration. Compared with the original configuration, the closure of the forebody shock wave and the incident shock wave at the lower lip of the modified configuration is improved, the strength of the reflected shock wave in the internal contraction section and the shock wave train in the isolation section is decreased, and the separation area of the internal flow channel caused by the boundary layer interference of the shock wave is reduced. The flow coefficient at the design point is increased by 3.22%, and the total pressure recovery coefficients of the throat and exit at the design point are increased by 2.41% and 0.31%, respectively. Moreover, the aerodynamic performances at the lift-weight balance point and in the wide-speed range are also significantly improved. In summary, the integrated design of waverider forebody / inward turning inlet proposed in this paper offers better lift-drag and flow-capture performance, providing valuable insight for the aerodynamic design of the longrange hypersonic cruise vehicle.