STUDY ON FLOW PATTERN BASED ON PRESSURE LOSS IN THE AIR-LIQUID TWO PHASE PIPE FLOW

Abstract

It is possible to transport the conveyance of mixture fluids such as emulsified oil, high viscosity solution, and the liquid including algae by using compressed air. The flow pattern in a pipe line of the transportation become air-liquid two phase flow especially slug flow. However, when a pipe line length was short, slug velocity did not change and it became clear that slug velocity is increase became the pipe length get longer. The increase of slug velocity is a thing by a pressure drop, which is expansion of compressed air, but does not became clear about an effect of the air with a few studies for long pipe line. We examined the effect of pressure of compressed air in long distance conveyance and examined that is increase of slug velocity due to the expansion of air and pressure drop concerning flow pattern. As the conclusion of this paper shows the results of experiments which was carried out in a 38mm diameter horizontal pipe with 600m long. The main pressure drop was substantiated by measurements of wall pressure using high frequency pressure transducers and observations of slow moving liquid in the film ahead of slug flow. This investigation shows two contributions to the pressure drop across a slug. The first is the pressure drop that results from the acceleration of the slow moving liquid film to slug velocity. Another is the pressure drop is required to overcome wall shear in the back section of the slug.