Vibroacoustic Coupling of Piping with Rubber Hose and Elastic Supports
The free stress and pressure waves in fluid filled piping are investigated numerically. The motivation of this work is to find measures and rules for the low frequency vibration and noise reduction for piping designers. The Timoshenko beam equation and ex
- PDF / 416,587 Bytes
- 6 Pages / 439.37 x 666.142 pts Page_size
- 42 Downloads / 216 Views
Abstract The free stress and pressure waves in fluid filled piping are investigated numerically. The motivation of this work is to find measures and rules for the low frequency vibration and noise reduction for piping designers. The Timoshenko beam equation and extended water hammer equation are used to calculate the transfer matrix of two piping configurations. And the wave propagation constants are then obtained by get the eigenvalue of the transfer matrix. It’s found that when the support stiffness reaches a critical value kc the piping will be a long bend wave filter. It’s the same as obtained by increasing the support distance. The flexible hose shows good performance in controlling both stress and pressure waves, but the support shows insignificant capability in pressure wave reduction.
Keywords Wave propagation Pipe support Flexible hose Vibration reduction
1 Introduction Piping systems in vessels, power plants, and oil supply system always undergo vibration, flow excitation and pulsations from pump and valve. Flexible hoses and dampers are commonly used to reduce the vibration and noise caused by these sources. Generally, most of the middle and high frequency noise reduced by these components readily. However, for the low frequency noise control, it’s necessary to tend to the layout of piping. Moreover, vibration from pump and the fluid borne sources are mainly long waves. It would be helpful to piping designers if there are instructions on how to make use of those measures. Unfortunately, few studies in the literature touch upon this area. Koo and Park (1998) had investigated the Z. Yin (&) W. Wu Z. Weng China Ship Scientific Research Center, Wuxi, Jiangsu, China e-mail: [email protected]
Y. Zhou et al. (eds.), Fluid-Structure-Sound Interactions and Control, Lecture Notes in Mechanical Engineering, DOI: 10.1007/978-3-642-40371-2_39, Ó Springer-Verlag Berlin Heidelberg 2014
265
266
Z. Yin et al.
possibility of reduce the fluid conveying piping vibration by using periodic supports. Their research validated the applicability of the periodic supports to vibration reduction, but didn’t give advice on how to place the supports. The present paper focuses on the low frequency vibration and acoustic wave propagation features in liquid filled piping with flexible hoses and supports. A comprehensive parametric study has been made to get the relationship between the configuration of the piping and the attenuation of waves, and general design rules are put forward accordingly.
2 Parametric Study 2.1 Numerical Method Fluid filled cylindrical pipe behaves as a beam below its cut-on frequency. For most of the industry piping, vibration sources from rotating machine and fluid flow are well below its cut-on frequency. So the extended water hammer equations and a fluid filled Timoshenko beam equation (Wiggert and Tijsseling 2001) is adopted to study the axial and bend wave transmission in piping, respectively. According to these equations, the wave propagation constants for piping with flexible hose and su
Data Loading...
