Yaw control of a flying-wing unmanned aerial vehicle based on reverse jet control

Abstract

Due to its layout, there are difficulties in realizing heading attitude control of a flying-wing unmanned aerial vehicle. In this paper, a reverse jet control scheme has been designed: (1) to replace the resistance rudders that are used for the yaw control of a conventional flying-wing unmanned aerial vehicle, (2) to assist and optimize heading attitude control, eliminate the adverse effects of the control surface and enhance stealth performance, and (3) to promote the use of rudderless flight for flying-wing unmanned aerial vehicles. To explore the control mechanism and the flow field of the reverse jet scheme, three-dimensional numerical simulations and low-speed wind tunnel experiments were carried out. First, the numerical simulations evaluated the feasibility and effectiveness of the reverse jet control scheme and explored and optimized the excitation parameters for the scheme. Then the forces were measured in a wind tunnel, and particle image velocimetry experiments were carried out. A reverse jet actuator was independently designed to verify the results of the numerical simulation. The results show that when the reverse jet excitation is applied, the jet obstructs the mainstream, destroys the flow field at the excitation position, and causes early separation of the flow, which increases the pressure drag on the wings and produces a control effect. The control effect mainly depends on the separation degree of the leeward surface. The larger the jet momentum coefficient is, the smaller the jet angle is, and the closer the excitation position is to the leading edge, the greater the separation degree of the leeward surface is, the better the heading attitude control effect is.

Researches on the aerodynamic and stealth characteristics for flying wing fighter

“…In this paper, the aerodynamic analysis was based on the large-scale parallelized structured grid RANS solver PMB3D [11] of the China Aerodynamic Research and Development Center (CARDC). The Van Leer scheme was introduced for the inviscid term, the central scheme was used for the viscous term.…”

Effects of Coanda jet direction on the aerodynamics and flow physics of the swept circulation control wing

“…16 In 2019, MAGMA, a flying-wing flapless UAV, conducted a successful flight test, 17 using improved supersonic Coanda jet technology for higher CC efficiency. Similar trial flights were also operated by Shi et al, 10,18,19 and the trailing-edge CC system has been applied on a conventional-layout UAV, 18 a canard configuration, 10 and a flying wing. 19 These successful flight tests boost confidence in CC technology, while they do not provide much insight into the flow physics of a swept CC wing, which is precisely what computational fluid dynamics (CFD) is good at.…”