Analysis on characteristics of new muffler for marine pipelines
XU Wei-Wei, WU Da-Zhuan, WANG Le-Qin, HAO Zong-Rui
(1.Institute of Chemical Machinery Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China; 2.Institute of Oceanographic Instrumentation, Shandong Academy of Science, Qingdao, Shandong 266001, China)
In order to reduce pipelineradiated 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 onedimensional 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. Fluidsolid coupling finite element software Adina was used to evaluate the muffler′s capacity of reducing pulsation. The results show that the onedimensional calculation model is in agreement with 3D finite element model in predicting the transmission loss of the muffler. The pipelineradiated 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 pipelineradiated 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% .
Bao Jiahan,Pan Ziwei,Xu Peimin,et al. Vibration analysis on a pipe system of pumps based on fluidstructure interaction[J].Journal of Drainage and Irrigation Machinery Engineering, 2010, 28(4):349-353.(in Chinese)
Oz H R. Nonlinear vibrations and stability analysis of tensioned pipes conveying fluid with variable velocity[J]. International Journal of NonLinear Mechanics, 2001, 36: 1031-1039.
Kaewunruen S, Chiravatchradej J, Chucheepsakul S. Nonlinear free vibrations of marine risers／pipes transporting fluid[J]. Ocean Engineering, 2005, 32(3／4): 417-440.
Ni Q, Zhang Z L,Wang L. Application of the differential transformation method to vibration analysis of pipes conveying fluid[J]. Applied Mathematics and Computation, 2011, 217(16):7028-7038.
Tian Hua′an, Liu Gongmin, Yang Yongqiang. Emulational investigation of resistance loss of silencer used in seawater pipeline [J]. Journal of Heilongjiang Institute of Science and Technology, 2004, 14 (1):29-32. (in Chinese)
Cao Weidong, Zhang Xiaodi, Gao Yi. Coherent structure on boundary layer wall induced by local micro vibration under adverse pressure gradient[J]. Journal of Jiangsu University: Natural Science Edition, 2011, 32(5):522-527. (in Chinese)