Abstract:Volutes have significant impact on the generation and propagation of flow-induced noise in centrifugal pumps. A volute with rectangular cross-section is designed to replace the original one with horseshoe-shaped cross section; subsequently, fluid dynamics simulation and acoustics computation are carried out in a centrifugal pump which is composed of the same impeller and either newly designed or original volute. The generation and propagation of flow-induced noise in the pump is solved by using a hybrid algorithm in which large eddy simulation and acoustic finite element analysis are combined based on the Lighthill acoustic analogy theory. The effects of cut-water of the volute on the pump head, efficiency and acoustic performance are also analyzed by employing two cut-water shapes, namely sharp and round edges. Some simulation results are verified by the existing experimental data. The analysis results show that both kinds of volute produce a similar hydraulic performance and result in a 290 Hz dominating frequency, i.e. blade passing frequency, for the noise. The volute with rectangular cross-section exhibits a better flow pattern than that with horseshoe-shaped cross-section according to the pressure contours, velocity vector distribution and flow direction inside the two pumps. Further the volute with rectangular cross-section lowers the averaged sound pressure level by 5 dB, showing an improved acoustic performance. Compared with the volute with sharp edge cut-water, the volute with round edge cut-water not only demonstrates a better hydraulic performance, but also possesses a more attractive acoustic behavior in account of 4 dB averaged sound pressure level reduction.
[1]袁寿其, 司乔瑞, 薛菲, 等. 离心泵蜗壳内部流动诱导噪声的数值研究[J]. 排灌机械工程学报, 2011,29(2): 93-98. Yuan Shouqi, Si Qiaorui, Xue Fei, et al. Numerical calculation of internal flow-induced noise in centrifugal pump volute[J]. Journal of Drainage and Irrigation Machinery Engineering,2011,29(2):93-98.(in Chinese)[2]王勇,刘庆,刘东喜,等.不同叶片冲角离心泵内流诱导振动噪声研究[J].流体机械,2013,41(7):1-4,32. Wang Yong,Liu Qing,Liu Dongxi,et al. Analysis of flow induced vibration and noise in centrifugal pumps with different blade inlet incidence angle[J]. Fluid Machinery, 2013,41(7):1-4,32.(in Chinese)[3]Johann F G. Centrifugal Pumps[M]. New York: Springer, 2008.[4]Langthjem M A,Olhoff N. A numerical study of flow-induced noise in a two-dimensional centrifugal pump—Part II:Hydroacoustics[J]. Journal of Fluids and Structures, 2004, 19(3): 369-386.[5]Chu S, Dong R, Katz J. Relationship between unsteady flow, pressure fluctuations, and noise in a centrifugal pump—Part A: Use of PDV data to compute the pressure field[J]. Journal of Fluids Engineering, 1995, 117(3): 24-29.[6]Chu S, Dong R, Katz J. Relationship between unsteady flow, pressure fluctuations, and noise in a centrifugal pump—Part B: Effects of blade-tongue interactions[J]. Journal of Fluids Engineering, 1995, 117(3): 30-35.[7]Si Qiaorui, Yuan Shouqi, Yuan Jianping, et al. Study on the influence of volute to flow-induced noise in centrifugal pump[J]. Advanced Material Research, 2012, 1009: 516-517.[8]司乔瑞, 袁寿其, 袁建平, 等. 基于CFD/CA的离心泵流动诱导噪声数值预测[J]. 机械工程学报, 2013, 49(22): 177-184. Si Qiaorui, Yuan Shouqi, Yuan Jianping, et al. Flow-induced noise calculation of centrifugal pumps based on CFD/CA method[J]. Journal of Mechanical Enginee-ring, 2013, 49(22): 177-184.(in Chinese)[9]Timusher S. Development and experimental validation of 3D acoustic-votex numerical procedure for centrifugal pump noise prediction[C]//Proceedings of ASME Flui-ds Engineering Division Summer Meeting, 2009: 389-398.[10]Claus W, Thomas H, Pierre S. Large-Eddy Simulation for Acoustics [M]. Cambridge: Cambridge University Press, 2007.[11]王治国. MSC.ACTRAN工程声学有限元分析理论与应用[M]. 北京:国防工业出版社,2007.[12]Heng Yaguang, Yuan Shouqi, Hong Feng, et al. A hybrid method for flow-induced noise in centrifugal pumps based on LES and FEM[C]//Proceedings of ASME Fluids Engineering Division Summer Meeting, 2013: 16594.[13]Keller J, Parrondo J, Barrio R, et al. Effects of the pump-circuit acoustic coupling on the blade-passing frequency perturbations[J]. Applied Acoustics, 2014, 76: 150-156.[14]杜功焕. 声学基础[M]. 南京:南京大学出版社, 2001.