在分析多通道单极子次级源控制系统的基础上,提出一种幅度调节型组合次级声源,这种组合源由两个单极子声源构成,单极子声源的间距远小于声波的波长。文中就组合次级源在自由场中对不同初级声源辐射噪声的控制进行理论分析和实验验证,并与同等条件下的单极子次级源控制系统的降噪性能进行了比较分析。数值计算和实验结果均表明,对于不同的初级声场,在次级通道数相同的情况下,组合次级源控制系统可以得到比单极子次级源控制系统高的降噪量。
Based on the analysis of active control system with multi-channel monopole secondary sources, an amplitude adjustment compound secondary source is proposed in this paper. The proposed compound secondary source consists of two closely located monopole sources with their distance much smaller than a wavelength. Theoretical analysis and experiments on the compound source for different primary sources in the free field are given. The noise reduction characteristics of the compound secondary sources control system and the monopole secondary sources control system are compared under the same conditions. For different primary sound fields, both numerical and experimental results show that the compound secondary sources control system can provide larger noise reduction than the monopole secondary sources control system on condition that the numbers of control channels in the two systems are the same.