Frequency Characteristics of Unsteady Flow of Cylindrical Choke in a Hydraulic Pipe

유압관로에서 원통형 초크의 비정상 유동의 주파수 특성에 관한 연구

A new instantaneous flowmeter for hydraulics by means or cylindrical chokes is developed. In this method the instantaneous flowrate through chokes is predicted in real time from measurement of pressure difference on both sides of cylindrical choke. The experimental study for the flowrate of pulsating flow in a pipe is carried out to measure differential pressure drop by using a strain gauge pressure transducer with data acquisition and processing system. A pulsating flow is verified by a 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 ratio of inertia term to pressure term($\phi_{t.1}$) and ratio of viscous term to pressure term($\phi_{z.1}$) are introduced to describe the flow pattern of laminar pulsating flow.