• Title/Summary/Keyword: 유압관로

Search Result 43, Processing Time 0.021 seconds

A Method for Measuring the Frequency Series Wave Speed in Hydraulic Hose (유압 호스에서의 주파수 계열 음속 계측법 개발)

  • Kang, M.K.;Lee, I.Y.
    • Transactions of The Korea Fluid Power Systems Society
    • /
    • v.3 no.2
    • /
    • pp.21-26
    • /
    • 2006
  • With the increasing concerns on noise and vibration in hydraulic fluid power systems, it is important to find better way to reduce noise and vibration. In this study, the authors survey former researches on hose(viscoelastic tube) modeling in advance. And a summary of several existing methods for measuring the speed of sound in the fluid in pipes is presented. Their basic principles, advantages and limitations are compared. And The authors suggest a far simple identification procedure to obtain wave speed in hose by just using an experimental pressure data for the object tube with hose. In the new procedure, flow in hose is basically modeled by transfer matrix method, and wave speed in hose is obtained as data in frequency series. The wave speed in hose as data in frequency series will be used to compute the pressure pulsation attenuation in hydraulic pipe systems. The computed results are compared with the experimental ones, and the validity of the new procedure to obtain wave speed in hose is confirmed

  • PDF

Impedance Characteristics of an Expansion-Resonator Type Pulsation Attenuator(Attenuation on Flow and Pressure Ripple form a Hydraulic Piston Pump) (팽창 공명기형 맥동 감쇠기의 임피던스 특성(유압용 피스톤 펌프의 유량.압력맥동 감쇠))

  • 이상기
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.9 no.1
    • /
    • pp.88-95
    • /
    • 2000
  • In this paper, an expansion-resonator type pulsation attenuator is proposed to absorb and attenuate flow an pressure ripple with high frequencies generated from hydraulic control systems. The basic principle of a pulsation attenuator proposed here is applied to propagation, reflection, absorption of pressure waves at the cross section of discontinuity and resonance in the pipeline. It has advantage of the compact size and high degree fo freedom for installation in hydraulic systems. The design scheme based on distributed parameter pipeline system with dissipative viscous compressible model is developed. To investigate the reduction of flow and pressure ripple with high frequencies produced by swash plate type axial piston pump, two kinds of attenuators are manufactured. It is experimently confirmed that the spectral intensity of flow and pressure ripple with high frequencies from the pump are reduced up to about 20$^{\circ}$~30dB by using attenuators proposed here. The calculated results were in good agreement with the measured values. From there sults of this study, it is shown that an expansion-resonator type pulsation attenuator is effective in a wide frequency ranges to attenuate the flow and pressure ripple from hydraulic components.

  • PDF

Behavior and flow characteristics of pulsating flow in the jetflow region through cylindrical chokes (유압관로내 원통형 초크의 분류영역에서 맥동유동의 거동과 유동특성에 관한 연구)

  • ;;Moh, Y. W.
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.19 no.11
    • /
    • pp.3041-3053
    • /
    • 1995
  • Cylindrical chokes are used widely as components of hydraulic equipments. The dynamic characteristics between flowrate and pressure drop through the cylindrical chokes were discussed by the frequency characteristics of the chokes. It was assumed no pressure recovery occurred near the downstream of the choke. The pulsating jetflow from the outlet of cylindrical chokes show very complex behaviours which are quite different from the steady jet flow but it's not clarified quantitatively. In order to utilize the chokes as a flowmeter, it is indispensable to discuss the estimation of the dynamics of pressure drop in the downstream jetflow region of cylindrical chokes. In this experimental study, it is clarified that the reattachment length depended on pressure wave is compared with it depended on velocity wave. A pulsating flow is verified by visualization method. In the present study, the flow characteristic variables of laminar pulsating flow are investigated analytically and experimentally in a circular pipe. Characteristic parameters of the ratios of inertia(.PHI.$_{t,1}$) and viscous(.PHI.$_{z,1}$) term to pressure term are introduced to describe the flow pattern of laminar pulsating flow. flow.low.