Multi-objective optimization design of S-shaped inlet with internal bump

Abstract

The multi-objective optimization design of S-shaped inlet with internal bump, considering both its aerodynamic and electromagnetic performance, is presented in this paper. The parametric design of S-shaped inlet with internal bump is carried out based on curvature control regulations, and the aerodynamic and electromagnetic characteristics of the inlet are obtained by means of Computational Fluid Dynamics (CFD) and Forward-Backward Iterative Physical Optics (FBIPO) methods, respectively. Subsequently, the Multi-objective Particle Swarm Optimization (MOPSO) algorithm based on Radial Basis Function (RBF) neural network is adopted to optimize the inlet for better performance, and the performance of the two non-dominated solutions selected from Pareto front is compared with the original model and the single S-shaped inlet. The results show that the shape of Best-1 is similar to the original model, except that the middle control plane of Best-1 is closer to the throat. The aerodynamic and electromagnetic characteristics of Best-1 are improved, and the corresponding objective functions are reduced by 29.82% and 40.55%, respectively. In contrast, the Best-2 model has a higher center offset at the first S bending section of the duct, leading to a further improvement in the electromagnetic characteristics, and the electromagnetic objective function is reduced by 70.33%. However, the flow quality of Best-2 model is deteriorated due to the large deflection of the airflow, with the aerodynamic objective function increasing by 70.47%. Although the aerodynamic performance of Best-2 has been reduced, its value can still meet the design requirements. Therefore, due to the considerable improvement of its electromagnetic characteristics, Best-2 will be selected as the optimal solution.