On the Self-Noise Reduction of Acoustic Treatments

拟议项目的主要研究目标是卡尔顿大学风洞的声学特性和修改，然后是各种声学处理和自噪声评估材料的测试。该项目的第一阶段将涉及风洞声学性能的测量。声学性能改进的要求将根据航空声学风洞所需的自噪声级来制定。同时进行计算流体动力学分析，以确定可能对风洞空气动力学性能的影响。这一阶段的工作将以背景噪声测量结束，以确认电路修改的效果。风洞背景噪声将在几个工作风速下确定。在项目的第二阶段，将在测试段地板上安装各种候选表面处理，并在风速范围内测量自噪声。将研究具有不同孔隙率、形态、图案和厚度水平的材料。将检查不同频率下的声音衰减程度。将对测量数据进行处理和分析，以证明几种治疗的能力。预计该项目的结果将导致新一代风洞和非常规表面处理的发展。

The main research objectives of the proposed project are the acoustic characterization and modification of the wind tunnel at Carleton University, followed by testing of the various acoustic treatments and materials for self-noise assessment. The first phase of the project will involve measurements of the wind tunnel acoustic performance. The requirements for the acoustic performance improvements will be developed based on the self-noise levels required for aeroacoustic wind tunnels. Simultaneous computation fluid dynamics analyses will be conducted to determine the likely compromises to the aerodynamic performance of the wind tunnel. This phase of the work will conclude with background noise measurements to confirm the effect of modifications to the circuit. Wind tunnel background noise will be determined at several operating wind speeds. During the second phase of the project, various candidate surface treatments will be installed on the test section floor and measurements of self-noise will be made over a range of wind speeds. Materials with different porosity, morphology, patterns and thickness levels will be investigated. The degree of sound attenuation at different frequencies will be examined. Measured data will be processed and analyzed to demonstrate the capabilities for several treatments. It is anticipated that results from this project will lead to the development of a new generation of wind tunnels and unconventional surface treatments.