Constitutive Equations for a Simulator of Airlift Pump in a Large Diameter Pipe using Drift-Flux Model

Abstract

One of the authors has developed a numerical simulator of airlift pump to solve governing equations represented by the drift flux model. The solver is based on the finite volume method which is known as SIMPLER algorithm for numerical scheme. The calculated results using the simulator were comparatively in good agreement with experimental ones by Weber et al. and Saito et al., despite lack of appropriate correlations used in the constitutive equations. In this study, the simulator is improved by a recent study (Ishii and Hibiki, 2011) on the constitutive equations of the drift flux model in the gas-liquid two-phase flow. The effect of newly incorporated correlations versus original ones in the constitutive equations is studied on the lifting characteristics such as relation between inputting air and lifted water. Also, flow characteristics along axial direction of pipes are examined to compare numerical results with experimental ones over wide range of pipe diameter and pipe length. Furthermore, pressure losses are grasped from the standpoint of the pump head, the relation between various pressure losses and lifting characteristics is discussed.

Keywords

• large diameter pipe
• airlift pump
• drift-flux model
• constitutive equation
• numerical simulation
• gas-liquid two phase flow