Control of spanwise flow induced separation on swept low aspect ratio wings to improve controllability

低高宽比扫描平面图，特别是那些具有对齐的前缘和后缘的平面图，由于其固有的低可观测性而日益受到关注。然而，由于在中等攻角下的气流破裂和分离过程，这些平面图只允许在“俯仰突变”发生之前利用少量的可用升力；俯仰力矩的迅速增加通常会导致偏离受控飞行。以前的工作已经确定了这种流动故障的原因是在较大攻角时引起的展向流动，导致向机翼后部的流动分离。在对集成和系统故障模式的影响相对良性的情况下，已经确定了将局部意义上的主动流动控制(AFC)应用于飞机的机会。其中最有希望的是应用AFC来补充传统的后缘控制在大攻角和/或大偏转下的有效性，以提高控制权威，并潜在地抵消分离时产生的大俯仰力矩。此外，亚利桑那大学最近进行的研究发现，从前缘吹入适量的气流可以影响展向流动及其对分离的影响；最近由曼彻斯特大学开发的基于1303 UCAV平台的岩浆研究飞机提供了合适的几何形状，以帮助理解在后掠型、低展弦比几何形状上的流动破裂的性质，并为未来的AFC和SJA测试提供了一个试验台。在可能的情况下，岩浆飞行试验将为该项目收集数据，并允许开发的新技术在飞行环境中进行测试。

Swept low aspect ratio planforms, particularly those with aligned leading and trailing edges are of increasing interest due to their inherently low observable characteristics. Due to the process of flow breakdown and separation at moderate angles of attack however, these planforms only allow for a small amount of the available lift to be utilised before 'pitch break' occurs; a rapid increase in the pitching moment which generally leads to departure from controlled flight. Previous work has identified the cause of this flow breakdown to be the spanwise flow induced at higher angles of attack which leads to flow separation toward the rear of the wing.Opportunities to apply Active Flow Control (AFC) in a localised sense to an aircraft have been identified where the impact on integration and system failure modes are relatively benign. The most promising of these is applying AFC to supplement the effectiveness of conventional trailing edge controls at high angles of attack and/or large deflections to improve control authority and potentially counteract the large pitching moments induced at separation.Additionally, recent research conducted at the University of Arizona has identified an impact modest amounts of blowing from the leading edge can influence the spanwise flow and its effect on separation; particularly where this blowing is oscillatory in the form of discrete 'Sweeping Jet Actuators (SJAs)'.The MAGMA research aircraft, recently developed at the University of Manchester and based on the 1303 UCAV planform provides a suitable geometry to aid understanding in the nature of flow breakdown over swept, low aspect ratio geometries and also provides a test bed for AFC and SJA testing in the future. Where possible, flight trials of MAGMA will gather data for this project and allow the new technologies developed to be tested in a flight environment.