A Study on Intermittent Water Jet

Abstract

Several methods were devised to study the behavior of the intermittent water jet used in the water jet loom, and the effects of the pump pressure, the supplementary air flow along the jet-stream and the water surface tension on the transition of the jet flow pattern, the jet-head velocity and the break-up length are observed, where the break-up length is the distance from the nozzle to a point where the jetstream first breaks its continuity. The followings are the main results obtained:(1) As the jet goes further from the nozzle, its flow pattern changes continuously from the smooth flow to the wavy flow and finally becomes the spray flow. There is a fist-like bump at the jet-head in the wavy flow.(2) The higher the pump pressure, the faster the transition of the flow pattern and the faster the highest jet-head velocity, but the shorter the break-up length.(3) The supplementary air flow retards the transition of the flow pattern and increases the breakup length.(4) The lower the water surface tension, the longer the break-up length. But some surface active agents increase the water viscosity and lower the highest jet-head velocity.