Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
LINEAR STABILITY ANALYSIS OF STRATIFIED TWO-PHASE FLOW IN A PLANE CHANNEL USING NUMERICAL SIMULATIONS
Submission Author:
Deibi Campos , RJ
Co-Authors:
Daniel Rodriguez, Igor Braga de Paula, Angela Nieckele
Presenter: Deibi Campos
doi://10.26678/ABCM.ENCIT2016.CIT2016-0324
Abstract
Linear stability theory has been used for decades for prediction of transition from stratified two-phase flow to other different flow regimes like slug, roll-waves or annular. The results from stability analysis of two phase flows in horizontal pipelines are often useful for a wide variety of industrial application in areas such as oil production, nuclear, chemical and many others. A major part of the works devoted to address the problem of instability in two phase flows consider that once the flow becomes unstable to growth of infinitesimal disturbances, there is a change in the flow pattern. A method extensively used in the literature to estimate whether disturbances would growth or decay is the linear temporal stability analisys. Although patial instability analysis is more closely related to practical applications, it has not been sistematically used for the problem at hand. This work presents a study of the linear stability of pressure-driven plane channel flow with two immiscible fluids with different viscosity and density at low Reynolds number, both in the temporal and spatial frameworks. As opposed to similar approaches based on the one-dimensional two-fluids model, which impose uniform velocity profiles for each phase, at the present work a two-dimensional formulation is employed with the VOF (volume of fluid) model to capture the interface. The conservation equations are solved with the finite volume method with a time and space second order schemes. Good agreement is obtained with results from a linear stability analysis analogous to the Orr–Sommerfeld equations for the dominant wavelengths, frequencies and phase velocities.
Keywords
Linear stability, Two-phase Flow, VOF Method, Orr-Sommerfeld approach
