Measurement of detailed flow statistics for trailing-edge noise prediction and mitigation

翼型噪声是典型的气动声学问题，任何有壁的噪声源，源于任何运输系统，或任何通风和发电系统。例如，它直接有助于预测和控制低速和高速风扇噪声，以及高升力装置或尾翼产生的机身噪声。因此，翼型噪声对当前和未来的重要环境和健康问题做出了回应，这些问题与空中交通的增加、自动驾驶汽车的普及以及嘈杂的工作条件有关。在连续三届工业主席的框架内，舍布鲁克大学（UdeS）的航空声学研究小组在翼型噪声方面积累了扎实的专业知识，为最先进的数值模拟做出了贡献，这些模拟揭示了几种新的噪声机制，并指导了几种快速分析模型的开发。后者可以在任何旋转机器的预设计阶段使用，现在集成在一个完整的独特的软件平台，正在商业化。然而，任何这种虚拟开发都需要详细的实验验证，这可以在加拿大独特的测试设施UdeS的气动声学风洞中实现。这样的验证过程不仅包括麦克风阵列的声学测量，以提供对噪声源方向性和实际源定位的洞察，还包括一些流量测量，从远程麦克风探头的压力测量到多线探头的局部热线风速测量，以及粒子图像测速（PIV）的全球场风速测量。后者已被证明提供有价值的信息三维湍流速度场围绕翼型尾缘，因此相关的噪声源。目前的提案旨在通过为研究小组提供更强大的激光器和升级的后处理PIV软件来保持和扩展这种能力，这应该能够使UdeS的实验气动声学小组赶上该小组已经实现的模拟数量。它还应该允许该小组将相同的技术应用于更大的视野和更复杂的实验设置，例如在并行的超高效率和安静风扇联盟和电动汽车内的电气冷却和空调模块合作研究项目中研究的复杂和完整的加热，通风和空调模块。这将提供一个前所未有的数据库和有价值的信息，为此类系统提供更安静的解决方案。

Airfoil noise is the canonical aeroacoustic problem for any wall-bounded noise sources, stemming from any transportation system, or any ventilation and power generation systems. For instance, it directly contributes to the prediction and control of low and high speed fan noise and of airframe noise generated by high lift devices or empennages. As such, airfoil noise responds to important present and future environmental and health issues related to increasing air traffic, proliferation of autonomous vehicles and noisy work conditions. Within the framework of three consecutive Industrial Chairs, the Aeroacoustic research group at Université de Sherbrooke (UdeS) has developed a solid expertise on airfoil noise contributing to state of the art numerical simulations that have unveiled several new noise mechanisms and guided the development of several fast analytical models. The latter can then be used at a pre-design stage of any rotating machine and are now integrated in a complete unique software platform that is being commercialized. Yet, any of this virtual development requires a detailed experimental validation that can be achieved in the aeroacoustic wind tunnel at UdeS, a unique test facility in Canada. Such a validation procedure not only involve acoustic measurements with arrays of microphones to provide insight on the noise source directivity and the actual source localization, but also several flow measurements ranging from pressure measurements with remote microphone probes to local hot-wire anemometry with multiple wire probes, and global field anemometry by Particle Image Velocimetry (PIV). The latter has been shown to provide valuable information on the three dimensional turbulent velocity field around the airfoil trailing edge, and therefore the associated noise sources. The present proposal is then meant to maintain and extend such a capability by providing the research group with a more robust laser and an upgraded postprocessing PIV software, which should able the experimental aeroacoustic group at UdeS to catch up with the number of simulations already achieved by the group. It should also allow the group to apply the same technique to larger fields of view and to more complicated experimental setups such as complex and complete heat, ventilation and air conditioning modules as studied in the parallel Consortium for Ultra HighEfficiency and Quiet Fans and in the Collaborative Research Project on electrical cooling and air conditioning modules within electrical vehicles. This will provide an unprecedented database and valuable information to yield quieter solutions for such systems.