Mathematical simulation of fluid flow in gas-stirred liquidsystems

Abstract

In the present paper, based on the two-phase (Eulerian-Eulerian) model, the3D fluid flows in gas-stirred systems, i.e. air-stirred water vessel andargon-stirred liquid steel ladle, are simulated. In the Eulerian-Euleriantwo-phase model, gas and liquid are considered to be two different continuousfields. The phases are assumed to share space in proportion to their volumefractions. The exchange between the phases is represented by source terms inconservation equations. Turbulence simulated by the k-ε modelis assumed to be the property of the liquid phase. The effects of mathematicaltreatments and operational factors, such as the inter-phase drag force, theturbulent model, the size of bubble and the gas-injection mode, on the fluidflow are discussed.Some interesting results are derived. Except the inter-phase dragforce, the inter-phase lift force should be taken into account inorder to exactly simulate the fluid flow in gas-stirred systems.The suitable turbulent model and drag coefficient have an effecton the mathematical simulation. Injecting small bubbles cangenerate a well mixing flow condition. The distance between thetwo gas-injection nozzles has effect on the fluid flow.