基于耦合仿生的机翼气动噪声控制研究

With the starting of "Large Aircraft Project", research on the airframe aerodynamics noise became extremely urgent. Traditional aeroacoustics models are unsuitable when faced with complex flow phenomenon and aerodynamic configuration. Bionics can be used to invent new technique or create new device through the simulation of biologic specific function, thus it may be used as a new-style tool for the control of airfoil aerodynamics noise. Recent observations and researches on the owls found that most of them can approximate their prey quietly and have the ability of "silent flight", thus they are regarded as the key bionic prototype for the design of "silent aircraft". In this project, we will research on the silent flight characteristics of the owl through biophysiography analysis and acoustic wind tunnel test. Then, the research results will be used as reference for the design of bionic coupling based airfoil. Mechanism research, numerical simulation and wind tunnel test will be used together to validate and improve the aerodynamics noise performance of the airfoil. Finally, new methods and technologies on bionic coupling based aerodynamics noise control will be established, which will offer a new and efficient measurement for the noise reduction of the aircrafts.

随着国家大飞机项目的启动, 机体气动噪声的控制研究迫在眉睫。传统的气动声学模型已无法适应复杂多变的流动现象和气动外形，仿生学通过模仿生物适应自身环境和生存需求的特殊功能来发明创造新的技术装置，为机翼气动噪声控制提供了新思路、新理念、新方法。近年来的观测和研究发现，鸟类中的猫头鹰能够悄无声息的接近猎物，具备“静音飞行”功能，是发展“无声”飞机的关键因素。本课题从猫头鹰静音飞行的生物形态学分析入手，揭示其静音飞行的耦合降噪机理并加以借鉴、创新进而对机翼进行仿生改形，并综合运用机理分析、数值模拟和风洞实验三大手段，对耦合仿生改形机翼的气动噪声性能进行研究、验证和改进，建立较为完善的基于耦合仿生的机翼气动噪声产生机理、传播特性和噪声控制的方法和实验技术，为开展飞机气动噪声控制提供一种新型有效的手段。

受静音飞行鸮翅膀表面和躯体部位降噪特征的启发，在国家自然科学基金青年科学基金项目“基于耦合仿生的机翼气动噪声控制研究”（编号11602290）的支持下，课题组对国内外在仿生降噪方面已有的研究成果进行了广泛调研和整理分析，相继提出了嵌入式尾缘锯齿模型、波浪状前缘锯齿模型、刷毛-锯齿耦合仿生模型、渐变多孔耦合仿生模型等多种新型结构，并设计加工了相应的仿生改形机翼模型。通过大涡模拟等数值计算方法详细研究了嵌入式尾缘锯齿、波浪状前缘锯齿对翼型流场和声场的影响；通过在声学风洞中开展噪声测量试验，对比分析了耦合仿生改形前后翼型的气动噪声情况，获得了10dB以上的降噪能力。依托课题研究内容，共在国内外学术期刊或会议上发表论文17篇（其中SCI检索4篇、SCI待检索1篇、EI检索8篇）、申请专利5项，实现了全部预设的研究成果。