基于可调频亥姆霍兹共振器的封闭空间噪声自适应半主动控制

针对实际中声场激励频率可能发生变化的情况,研究采用自适应频率可调的亥姆霍兹共振器吸声器来跟踪激扰频率从而控制封闭空间噪声。建立了封闭声腔与亥姆霍兹共振器耦合的频域模型与时域控制模型,并给出了三种频率调谐控制算法,即亥姆霍兹共振器开口处声压幅值最小和内部声压幅值最大,以及判断内部声压幅值和开口处声压幅值的点积值趋零(点积值法)。理论分析和数值计算结果表明点积值法调频效果明显优于其它两种算法。采用并设计一种颈部面积可调的可调频亥姆霍兹共振器,利用点积值调频算法进行了单频和带宽信号激励下封闭空间噪声控制仿真和单频激励下实验研究,结果表明:点积值调频算法具有较好的频率调节性能和调节精度,并取得了理想的噪声控制效果,验证了理论模型正确性及调频算法的有效性。

Adaptive semi-active noise control in enclosure using self-tuning Helmholtz resonators

The self-tuning Helmholtz resonator is studied in order to control the noise in the enclosure. According to modal superposition theory, the frequency-domain model and time-domain control model of enclosure-Helmholtz resonators (H.R.) are established. Three frequency tuning algorithms are adopted, that is, minimization of the sound pressures outside the H.R. throat, maximization of the sound pressure inside the H.R. cavity, and judgement of the dot-product of the sound pressures outside the H.R. throat and inside the H.R cavity called as dot-product method. Theoretical analysis and numerical results show that the dot-product method is superior to the others. A Helmholtz resonator whose neck is tunable is designed. The numerical simulations and experiments of noise control using the designed Helmholtz resonator and dot -product tuning method are conducted. The results demonstrate good noise control effect and frequency tuning accuracy.