On the Transient Behavior of Oil Flow under Negative Pressure

Abstract

The transient behavior of oil flow under negative pressure is studied experimentally. To observe negative pressure, three types of oil flow models are used. The pipe is 20 m in length, and 8 mm or 12 mm in diameter. The boundary conditions of three types are different from each other. Quick oparation of a valve mounted at the end of pipe causes a fluid transient. Negative pressure is measured using strain gauges on the outer surface of the pipe. By applying the principle of pressure difference meter, the relation between strain and negative pressure was tested equivalently. Negative absolute pressure was observed experimentally. The numerical calculation by means of characteristics method showed a good agreement with the experimental results. The condition of inner surface of the pipe has a great influence on the transient behavior under negative pressure.