Oscillating motions of slug flow in capillary tubes

✍ Scribed by S.B Liang; H.B Ma

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 763 KB
• Volume: 31
• Category: Article
• ISSN: 0735-1933
• DOI: 10.1016/j.icheatmasstransfer.2004.02.007

✦ Synopsis

A mathematical model describing the oscillation characteristics of slug flow in a capillary tube is presented. The model considers the vapor bubble as the gas spring for the oscillating motions in a capillary tube including effects of capillary force, gas spring constant, dimensions, gravitational force, and initial pressure distribution of the working fluid. Numerical results indicate that the isentropic bulk modulus generates stronger oscillations than the isothermal bulk modulus. While it demonstrates that the capillary tube diameter, bubble size, and unit cell numbers determine the oscillation, the capillary force, gravitational force, and initial pressure distribution of the working fluid significantly affect the frequency and amplitude of oscillating motion in the capillary tube. 2004 Elsevier Science Ltd

Introduction

Slug flow of vapor bubbles and liquid plugs as one fundamental two-phase flow has been investigated intensively by many researchers due to applications and unique features of structure properties. Recently, the pulsating heat pipes (PHP) as active cooling devices ([1-8]) have stimulated an interest in the two-phase flow in the capillary tubes. The PHP, characterized with a structure of vapor bubbles and liquid plugs, consists of an interconnected capillary tube bent into many turns. The diameter