船舶用输液管路新型消声器特性分析

为降低管路辐射噪声及流体脉动,设计一种用于输液管路的新型消声器,通过试验与数值计算相结合的方法评估其消脉降噪性能,采用一维模型与三维有限元模拟计算其传递损失,利用水听器测试安装消声器前后管口辐射噪声,并采用Adina流固耦合有限元软件评估其消脉性能．结果表明:一维计算模型与三维有限元模型预测消声器传递损失吻合较好;管口声辐射主要与管路动力装置周期噪声以及流体脉动频率有关,故降低流体脉动亦可降低管口声辐射;消声器针对特性频率具有消声效果,在6 000 Hz 1／3倍频程处,消声器降低声压级35 dB;在消声器内壁增加弹性元件,使流体与弹性壁发生耦合,有利于改善管道内流体的脉动,当流体脉动频率为250 Hz、弹性元件弹性模量为267 MPa时,消声器可降低流体脉动幅值达70％．

Analysis on characteristics of new muffler for marine pipelines

In order to reduce pipeline radiated noise and fluid pulsation, a new muffler was designed and developed. Through experiments and simulations, the performance of the new muffler was evaluated. Its transmission losses was calculated by one dimensional model and 3D finite element model. The radiated noise at the pipe mouth before and after the installation of the muffler was measured by a hydrophone and compared. Fluid solid coupling finite element software Adina was used to evaluate the muffler′s capacity of reducing pulsation. The results show that the one dimensional calculation model is in agreement with 3D finite element model in predicting the transmission loss of the muffler. The pipeline radiated noise is chiefly related to the cycle noise of the motion system of the pipeline and the fluid pulsation rate. Therefore, to reduce fluid pulsation can also reduce the pipeline radiated noise at the pipeline mouth. The muffler reduce radiated noise caused by some special frequencies significantly, the sound pressure level was reduced to 3.5 dB for the one third octave at 6 000 Hz. Elastomers added to the inner side of the muffler will couple the fluid and the elastomers, which is helpful in improving the fluid pulsation. When the fluid pulsation rate is 250 Hz and the elasticity coefficient of elastomer is 267 MPa, the amplitude of the fluid pulsation can be reduced up to 70% .