Propeller Aerodynamic Interaction and Noise Characteristics in Distributed Propulsion

在过去的二十年里，交通技术取得了巨大的进步，导致城市空中交通（UAM）领域的快速发展，无人机和短途电动飞机逐渐成为我们日常生活中不可或缺的一部分。UAM市场目前预计到2040年将达到1.5万亿美元的工业价值。与传统飞机的空气动力学和气动声学研究相比，配电推进（DP）和电动垂直起降（eVTOL）这两种有前途的绿色（即零排放）无人机构型的研究相对较少。该研究项目旨在通过实验测量和数值模拟，重点研究与分布式推进系统相关的流场相互作用及其对空气动力学产生的噪声的影响。研究将集中在两个主要的感兴趣的领域：（a）旋翼-旋翼干扰;（B）旋翼-机体干扰。该项目提供了全面、高保真的流场和噪声信息，将显著提高我们对分布式推进配置的认识和理解。因此，该项目是及时和必要的，因为英国。欢迎其“绿色重建”倡议，包括FlightZero和NetZero计划。该项目利用了布里斯托强大的数值和实验专业知识。数值模拟将使用格子玻尔兹曼方法（LBM）进行，用于复杂几何配置（即，多螺旋桨），并将在具有高度仪器化装置的航空声学风洞中进行实验测量，以揭示基本的流动和噪声产生机制。该项目还与ENODISE和SilentProp等新型推进配置中的几项大型EPSRC和H2020研究计划保持一致，该研究将学习并与这些项目中的合作伙伴合作，以产生更大的影响和传播结果，从而实现前瞻性的项目合作。此外，从所取得的成果中，预计将有三到四篇高质量的研究论文在主要期刊上发表，并在国内和国际会议和研讨会上发表，以进一步探索与感兴趣的机构和工业伙伴合作的潜在机会。本文的研究将有助于深入了解双旋翼布局的气动干扰和相关噪声特性，并有望：1。在DP系统中建立一套广泛的数值和实验数据集，重点关注叶片与叶片和叶片与机身的相互作用.对基于Lattice-Boltzman的求解器在复杂配置上进行评估。研究和理解近场空气动力学的变化及其与DP配置中不同参数的辐射噪声的物理关系。研究方法：该项目将利用最先进的数值工具和实验技术。对于数值模拟，将进行基于LBM的壁分辨模拟。该求解器在复杂外形上具有固有的优势。实验将在布里斯托的国家风洞设施中进行。仪表机身和噪声定位阵列的设计和建造与内部开发的传感器技术。与EPSRC保持一致：研究福尔斯属于空气动力学和流体动力学，这是EPSRC工程主题下的战略研究领域。项目合作伙伴：Vertical Aerospace作为该项目的工业顾问，从工业角度为DP配置提供指导。

The transportation technology has greatly advanced in the past two decades, leading to rapid development in the area of Urban Air Mobility (UAM), which sees the unmanned aerial vehicles and short-haul electric aircrafts to gradually become an integral part of our daily life. The UAM market is currently projected to reach an industrial value of 1.5 trillion USD by 2040. Compared to the research efforts into conventional aircraft aerodynamics and aeroacoustics, research into electrical distribution propulsion (DP) and electrical Vertical Take-Off and Landing (eVTOL) which are the promising green (i.e. zero-emission) configurations for UAM, remains relatively scarce. This proposed research project aims to focus on the flow interactions associated with the distributed propulsion system, as well as their influence on the aerodynamically generated noise by implementing experimental measurements and numerical simulations. The study will focus on two main areas of interest: (a) the rotor-to-rotor interaction; (b) the rotor to airframe interaction. With the comprehensive and high-fidelity flow field and noise information, the project will significantly improve our knowledge and understanding of distribution propulsion configurations. Therefore, the project is timely and essential as U.K. embraces on its 'Build Back Greener' initiatives, including the FlightZero and NetZero programmes. The project leverages upon the strong numerical and experimental expertise in Bristol. The numerical simulations will be carried out using Lattice Boltzman method (LBM) for scale-resolved and efficient simulation of complex geometrical configurations (i.e., multi-propeller) and the experimental measurements will be performed in the aeroacoustic wind tunnel with highly instrumented set-up to unravel the fundamental flow and noise generation mechanisms. The project is also aligned well with several large-scale EPSRC and H2020 research initiatives in novel propulsion configurations such as ENODISE and SilentProp, which the study will learn and work with the partners in those projects for greater impact and dissemination of the results, leading to prospective project collaborations. Moreover, from the obtained results, three to four high quality research papers are expected to be published on the leading journals, as well as presented in domestic and international conferences and seminars to further explore potential opportunities to collaborate with interested institutions and industrial partners.Aims and Objectives: The proposed research will shed light on understanding of the aerodynamic interaction and the related noise characteristics in DP configurations, and are expected to:1. Establish an extensive set of numerical and experimental datasets in DP system with a focus on blade-to-blade and blade-to-airframe interactions.2. Provide assessment of the Lattice-Boltzman based solver on complex configurations.3. Investigate and understand the modifications of the near-field aerodynamics and their physical relation to the radiated noise with varying parameters in DP configurations. Research Methodologies: The project will utilise the state-of-the-art numerical tool and experimental techniques. For numerical simulations, wall-resolved simulations based on LBM will be carried out. The solver has inherent advantages on complex configurations. The experiments will be carried out in the national wind tunnel facility at Bristol. The instrumented airframes and the noise localisation arrays are designed and built with sensor techniques developed in-house. Alignment with EPSRC: The research falls under Aerodynamics and Fluid Dynamics which is a strategic research area under EPSRC engineering theme. Project Partners: Vertical Aerospace acts as an industrial advisor of the project to provide guidance to the DP configurations with an industrial perspective.