Requirements and challenges of flow control technology in fighter aircraft design

As the core equipment for seizing air superiority, fighter aircraft rely heavily on aerodynamic design, and the application of aerodynamic technologies has driven the generational evolution of fighter jets. Faced with multiple stringent requirements for advanced fighter aircraft, such as high stealth performance, light weight, multi-mission load capacity and wide-speed range flight capability, higher challenges are posed to the selection of aerodynamic configurations and the development of aerodynamic design technologies. To meet the top-level design requirements and the demands of multi-disciplinary design, the development of novel flow control technologies and thermal management enabling technologies has attracted increasing attention. In particular, Active Flow Control (AFC) technology has emerged as a key technology with great potential due to its unique advantages. This paper focuses on sorting out the collaborative evolution process of fighter aircraft and flow control technologies, and clarifies the development vein of flow control technologies from passive and mechanical regulation types to active and intelligent adaptive ones. It further analyzes in depth the technical requirements and implementation paths for typical application scenarios including aerodynamic lift enhancement via wing flow control, control surface efficiency improvement, airframe-engine matching control and gust load alleviation. Focusing on three major development directions of future fighter aircraft, highly autonomous unmanned aerial vehicles and high-speed aircraft, the paper identifies key technical issues related to flow control technologies, such as aerodynamic configuration design under strong stealth constraints, multi-axis control de-coupling, modular adaptation and aerothermal matching. Finally, from three dimensions of aerodynamic efficiency improvement, full-life-cycle reliability assurance and engineering feasibility, the core challenges faced by the engineering application of flow control technologies are systematically elaborated, and the technical development direction of “flow field perception-intelligent decision-making-adaptive regulation” is prospected. The research results can provide theoretical support and engineering reference for the research and development of aerodynamic design and flow control technology application for future fighter aircraft.