Understanding the causes of noise emanating from the inter-wheel region of two-wheel landing gears and their mitigation

飞机起落架是大型钝体附件，会产生高度复杂和不稳定的流动，表现为噪音。飞机噪音不仅对居住在机场附近的人造成严重干扰，而且还与对人们健康的负面影响有关。为了限制噪音排放，航空当局制定了严格的规定，向航空公司征收与噪音相关的费用，为飞机运营商提供了财政激励，以尝试减少他们的噪音排放。因此，了解噪音产生的来源并尽可能减少噪音，符合许多不同方面的利益。 两轮起落架的轮间区域已被认为是产生噪声的潜在关键来源。特别是，在该区域观察到了以强烈的横流流体抛射为主导的严重流动行为。这项拟议的研究旨在确定这些弹射背后的潜在物理机制，以及起落架几何参数的变化如何影响横流弹射和由此产生的噪声。 通过这一领域知识的进步，梅西尔-布加蒂-道蒂(工业合作伙伴)将能够以最有潜力实现降噪的方式调整他们的起落架设计。这些好处将改善目前受到飞机噪音影响的普通民众的健康和福祉，并增加梅西尔-布加蒂-道蒂公司的竞争力。

Aircraft landing gears are large, bluff bodied appendages that create highly complex and unsteady flow, manifesting itself as noise. Aircraft noise not only causes significant disturbance to those that live near airports, it has also been associated with negative impacts on people's health. In an effort to restrict noise emissions, aviation authorities placed stringent regulations that impose noise related fees on airlines, providing a financial incentive for aircraft operators to try and reduce their noise emission. It is therefore in the interest of many diverse parties to understand the sources of noise generation and mitigate them wherever possible. The inter-wheel region of two-wheel landing gears has been identified as a potentially key source of noise generation. In particular, a severe flow behaviour dominated by strong cross-stream fluid ejections has been observed to occur in this region. The proposed research aims to identify the underlying physical mechanisms behind these ejections and how parametric changes to the landing gear geometry may affect both the cross-stream ejections and the resultant noise. Through the advancement of knowledge in this area, Messier-Bugatti-Dowty (the industrial partner) will be able to adapt their landing gear designs in a manner that will have the greatest potential to realize noise reductions. These benefits will improve the health and well being of the general populace that are currently impacted by aircraft noise, and increase the competitiveness of Messier-Bugatti-Dowty.