湍流脉动激励下板结构辐射噪声的多模态压电分流振动控制方法研究

Multi-mode resonances control of a panel’s vibration and sound radiation under turbulent boundary layer excitation by piezoelectric shunt networks

湍流脉动压力所引起的水动力噪声是高速航行水航行体的主要噪声源。针对湍流脉动压力激励下声纳平台结构的多模态振动控制问题,提出基于负电容压电分流被动控制方法的控制策略。采用四边简支流体加载平板结构模拟平台结构,湍流脉动压力模型使用Corcos模型。根据Hamilton变分原理建立流体-平板-多个压电分流电路系统的机电耦合动力学方程,以系统动能功率谱密度和辐射声功率作为评价指标,研究了不同来流速度下系统响应规律及不同压电分流电路的被动控制效果,针对不同控制目标确定了基于负电容-连通电路(CRLC)和负电容-电感-电阻并联电路(RLC)的控制策略。研究表明:负电容压电分流电路对不同来流速度下湍流脉动压力引起的简支板多模态振动有较强的控制效果;针对平板结构振动控制时,不考虑压电片数量限制时RLC电路控制效果较好;针对低频辐射声功率控制时,CRLC可使用单压电片达到控制效果,有效降低了水下航行体的水动力噪声。

The hydrodynamic noise caused by turbulent boundary layer(TBL) is one of the main noise sources of underwater vehicles. Aiming at the multi-modal vibration control of sonar platform under TBL excitation, the passive control strategies based on negative capacitive piezoelectric shunt are proposed. In this paper, the foursided simply supported fluid-loaded plate is used to simulate the sonar platform, and the Corcos model is selected as the TBL model. Based on Hamilton variation principle, the coupled electro-mechanical dynamic equations of piezoelectric shunt networks-plate-fluid system are established. The system response under various free stream velocities and the control performance of different piezoelectric shunts are studied in terms of kinetic energy power spectral density(PSD) and radiation power. The control strategies based on current flowing piezoelectric shunt with negative capacitance(CRLC) and inductor-resistance resonant parallel shunt with negative capacitance(RLC) are determined for different control targets. The results show that the negative capacitive piezoelectric shunt circuit is effective in controlling multi-mode vibration of simply supported plate caused by TBL at various free stream velocities. The control effect of RLC circuit is better when the number of piezoelectric patches is not restricted in vibration control. For sound radiation power control, CRLC circuit can use a single piezoelectric patch to achieve the control effect, thus effectively reducing the hydrodynamic noise.