Multi-objective aerodynamic design optimization of a new engine intake electromagnetic wave blocker

Abstract

A new engine intake electromagnetic wave blocker (EMWB) in a straight duct configuration is proposed as an alternative to S-shaped air intake ducts for reducing radar and infrared signatures of aircraft. A computational fluid dynamics model is developed and verified against an existing S-duct air intake study. Ten geometric parameters of the baseline EMWB are selected as design variables for a multi-objective optimization study. The design space is extensively explored with 68 configurations applying the constraints of pressure recovery (PR) > 0.97 and distortion coefficient (DC<inf>60</inf>) < 0.06. This process yields 16 feasible designs from which the best performing model in terms of PR and DC<inf>60</inf> is selected as the optimized EMWB. The electromagnetic model and experimental setup are then established. Radar cross-sectional measurements of the optimized EMWB model demonstrate significant improvements: aerodynamic performance is increased by 8.1% for PR and 14% for DC<inf>60</inf> while the radar cross section is decreased by 51%. These results suggest that the optimized EMWB in a straight duct configuration offers a promising alternative to S-shaped ducts for reducing aircraft engine signatures while maintaining aerodynamic performance. © 2025 Elsevier B.V. All rights reserved.