Eulerian Two-phase Model Research Articles

Evaluation of Advanced Two-Phase Flow and Combustion Models for Predicting Low Emission Combustors

The development of low-emission aero-engine combustors strongly depends on the availability of accurate and efficient numerical models. The prediction of the interaction between two-phase flow and chemical combustion is one of the major objectives of the simulation of combustor flows. In this paper, predictions of a swirl stabilized model combustor are compared to experimental data. The computational method is based on an Eulerian two-phase model in conjunction with an eddy dissipation (ED) and a presumed-shape-PDF (JPDF) combustion model. The combination of an Eulerian two-phase model with a JPDF combustion model is a novelty. It was found to give good agreement to the experimental data.

Consolidation of concentrated suspensions – numerical simulations using a two-phase fluid model

We investigate numerically a mathematical model of a consolidation process of a dense, flocculated suspension. The suspension is treated as a two-constituent mixture of a fluid and solid particles by an Eulerian two-phase fluid model. We characterize the suspension by constitutive relations concerning the stresses, interaction forces and inter-particle forces. A numerical solver for a two dimensional test case is developed using finite difference methods both in time and space. In the numerical experiments, the suspension is confined to a closed box and consolidates due to a constant gravity field directed toward the bottom. To study the effect of shear, 2D simulations are performed where the bottom wall of the box is moving with a constant speed.

Effect of interphase lift force on fluid flow in air stirred cylindrical vessel

In the present paper, based on the two-phase model (Eulerian model), the two-dimensional fluid flow in air stirred water systems is simulated, and the effect of interphase lift force on the fluid flow is specially discussed. In the Eulerian two-phase model, the gas and liquid phases are considered to be two different continuous fluids interacting with each other through the finite interphase areas. The exchange between the phases is represented by source terms in conservation equations. Turbulence is assumed to be a property of the liquid phase. The k–ɛ model is used to describe the behaviour of the liquid phase. The dispersion of phases due to turbulence is represented by introducing a diffusion term into the mass conservation equation. The contribution of bubble movement to the turbulent energy and its dissipation rate are taken into account by adding extra volumetric source terms to the equations of turbulent energy and its dissipation rate. Comparison between the mathematical simulation and experimental data indicates that the interphase lift force has a strong effect on flow behaviour, and considering both drag force and lift force as interphase forces is important to accurately simulate the gas–water two-phase fluid flow in air stirred systems. The interphase lift force makes bubbles move away from the centreline; the gas concentration decreases near the centreline, and increases near the wall. The lift force is smaller than the drag force at the same place, especially far away from the centreline.