Measurement of Liquid Film Thickness of Accelerated and Decelerated Slug Flows in Micro Tubes

摘要

Liquid film formed between confined vapor bubble and tube wall plays an important role in micro-scale two phase flows. The liquid film thicknesses in accelerated and decelerated flows under adiabatic condition are experimentally investigated. Laser focus displacement meter is used to measure the liquid film thickness. Water is used as a working fluid and a circular tube with inner diameter of 1 mm is used. The acceleration and deceleration make the liquid film thinner and thicker, respectively, than in a steady flow. It is also found that the initial flow velocity cannot be neglected in accelerated and decelerated flows at large initial flow velocities.