Effect of Oil Viscosity on Self-Excited Noise Production inside the Pilot Stage of a Two-Stage Electrohydraulic Servo-Valve

[+] Author and Article Information
Meng Chen

Department of Fluid Control and Automation, Harbin Institute of Technology, Box 3040, Science Park, No.2, Yikuang Street Nangang District, Harbin 150001, China, MCC Huatian Engineering & Technology Corporation

Nay Zar Aung

Department of Mechatronic Engineering, Yangon Technological University, 3rd Floor, TRC Builiding, YTU Campus, Insein Road, Yangon 11181, Myanmar

Songjing Li

Department of Fluid Control and Automation, Harbin Institute of Technology, Box 3040, Science Park, No.2, Yikuang Street Nangang District, Harbin 150001, China

Changfang Zou

MCC Huatian Engineering & Technology Corporation, No.18, Fuchunjiangdong Street, Jianye District, Nanjing 210019, China

1Corresponding author.

ASME doi:10.1115/1.4040500 History: Received September 07, 2017; Revised June 01, 2018


The occurrence of self-excited noise felt as squealing noise is a critical issue for an electrohydraulic servo-valve that is an essential part of the hydraulic servo-control system. Aiming to highlight the root causes of the self-excited noise, the effect of oil viscosity on the noise production inside a two-stage servo-valve is investigated in this paper. The pressure pulsations characteristics and noise characteristics are studied at three different oil viscosities experimentally by focusing on the flapper-nozzle pilot stage of a two-stage servo-valve. The cavitation-induced and vortex-induced pressure pulsations characteristics at upstream and downstream of the turbulent jet flow path are extracted and analyzed numerically by comparing with the experimental measured pressure pulsations and noise characteristics. The numerical simulations of transient cavitation shedding phenomenon are also validated by the experimental cavitation observations at different oil viscosities. Both numerical simulations and experimental cavitation observations explain that cavitation shedding phenomenon is intensified with the decreasing of oil viscosity. The small-scale vortex propagation with the characteristic of generating, growing, moving and merging is numerically simulated. Thus, this study reveals that the oil viscosity affects the transient distribution of cavitation and small-scale vortex, which in turn enhances the pressure pulsation and noise. The noise characteristics achieve a good agreement with pressure pulsation characteristics showing that the squealing noise appears accompanied by the flow field resonance in the flapper-nozzle. The flow-acoustic resonance and resulting squealing noise possibly occurs when the amplitude of the pressure pulsations near the flapper is large enough inside a two-stage servo-valve.

Copyright (c) 2018 by ASME
Your Session has timed out. Please sign back in to continue.






Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In