Aerodynamic shape optimization design of airframe/propulsion integrated hypersonic aircraft with aerodynamics/trajectory/control coupling

To address the multidisciplinary coupling problem faced by the air-breathing hypersonic airframe/propulsion integrated design, a two-layer multidisciplinary optimization design method is proposed based on flight mission requirementsand considers aerodynamics, trajectory, and control. Firstly, an optimization method for the geometric parameters is established using sequential quadratic programming to optimize the flight performance such as flight rangeand duration, with controllability as the constraint. Then, by solving the Reynolds Average Navier-Stokes (RANS) equations, the aerodynamic characteristics of the selected shape is obtained. With the obtained aerodynamic data, a mapping model from geometric parameters to aerodynamic characteristics is constructed. Subsequently, based on the existing dynamic data, a thrust model of the scramjet engine considering the influence of forebody parametersand nozzle parameters is established. After that, an internal trajectory optimization method is proposed. This method maintains the same optimization objectiveand constrain as geometric parameter optimization, and adopts the direct shooting method for discreteand the SQP algorithm for optimization. In addition, a control simulation model is constructed based on, which was combined with the to establish an aerodynamic, trajectoryand control integrated design method inner trajectory optimizationand outer parameter optimization are combinedand the Active Disturbance Rejection Control (ADRC) technology is used evaluate trajectory controllability, achieving two-layer multidisciplinary optimization for airframe/propulsion integrated design. Finally, optimization of the shape parametersand aircraft trajectory of the SR-72-like hypersonic vehicle are carried out to achieve the optimal range. The optimization results show that the maximum range is increased by 28.98% during the whole flight mission, demonstrating the effectiveness of the proposed method.