Abstract:

The noise of wind tunnels sharply decreases the reliability and precision of wind tunnel experiments. Thus to decrease noise of wind tunnels has become a key technical issue of wind tunnel construction. This paper put forward 1-D discrete noise by ANC based on Fx-LMS. The results indicate that it can minimize the error caused by microphone mismatch, decrease the effects of the changing of weight coefficients on the system, and then increase the system convergence speed. According to the experiments on the duct by active noise control technical after optimized algorithm parameters in anechoic chamber of 0.55m×0.4m aero-acoustic wind tunnel, it has good effects on noise decreasing.

摘要：

风洞噪声不仅直接影响人们的身心健康，更重要的是较大的背景噪声还降低了风洞声学试验能力和试验精度，降低风洞噪声已成为风洞建设中攻关的关键技术问题。因此提出基于Fx-LMS自适应控制算法实现一维离散噪声主动控制，实验结果表明其能有效解决单波麦克风失匹配带来的误差，减小权系数变化对系统的影响，提高系统收敛速度；根据优化后的算法参数，在0.55 m×0.4 m声学风洞消声室进行管道噪声主动降噪实验，获得理想的降噪效果。

关键词: 声学, 风洞, 背景噪声, Fx-LMS自适应算法, 主动控制, 降噪