离心泵用赫姆霍兹水消声器声学特性数值模拟

为了降低离心泵沿管路传播的辐射噪声，基于有限元理论，运用AnsysCFX软件对不同工况下离心泵出口压力脉动进行计算．研究了离心泵出口压力脉动特性，运用声学软件Sysnoise对内置和外置连接管、不同连接管长度、并联连接管、串联和并联共振腔以及改变串联和并联共振腔内连接管长度的赫姆霍兹水消声器的声学特性分别进行仿真，并分析其影响规律．仿真结果表明：连接管长度、连接管连接方式能有规律地改变赫姆霍兹水消声器的共振频率和传递损失；串联和并联共振腔可以同时出现多个共振频率，但串联共振腔产生的共振频率向其各自单腔的共振频率的两端移动，传递损失有所下降，且各腔内共振频率相互影响；并联共振腔产生的共振频率向其各自单腔的共振频率的内部移动，同时传递损失大幅增大，各腔内传递损失互不干扰．

Numerical simulation of acoustic performance of Helmholtz water-muffler for centrifugal pumps

In order to reduce the noise issued from centrifugal pump pipelines, the pressure fluctuations at the pump were calculated under different operating conditions by using the software Ansys CFX. The pressure fluctuations characteristics were investigated. Moreover, the acoustic performance of Helmholtz water-muffler with inner and outboard neck, different lengths of neck, parallel necks, series and parallel resonator cavity was analyzed by means of the acoustic software Sysnoise. The simulated results show that the length of neck, connection type between neck and resonator cavity affect the resonant frequency and transmission loss of Helmholtz water-muffler regularly. One more resonant frequency can appear in series and parallel resonator cavities, but the resonant frequencies in series cavities move towards both ends of the resonant frequency of each single cavity with slightly degraded transmission loss. Further there are interactions among the resonant frequencies in the cavities. The resonant frequencies in parallel cavities move towards the inside of two resonant frequencies each single cavity with increased transmission loss. Meanwhile, the interactions among the resonant frequencies in the cavities do not exist.