Homogeneous Mixture Model Simulation of Compressible Multi-phase Flows at All Mach Number

2021 ◽  
pp. 103745
Author(s):  
Young-Lin Yoo ◽  
Jong-Chan Kim ◽  
Hong-Gye Sung
Keyword(s):  
Mach Number ◽  
Mixture Model ◽  
Model Simulation ◽  
Homogeneous Mixture ◽  
Multi Phase ◽  
Homogeneous Mixture Model

Experimental Investigation of Large Particle Slurry Transport in Vertically Oscillating Pipe for Subsea Mining

2021 ◽  
Author(s):  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Masao Ono
Keyword(s):  
Mixture Model ◽  
Pressure Loss ◽  
Prediction Method ◽  
Axial Direction ◽  
Hydraulic Gradient ◽  
Solid Particles ◽  
Homogeneous Mixture ◽  
Pipe Model ◽  
Slurry Transport ◽  
Homogeneous Mixture Model

Abstract For subsea mining, it is important to predict the pressure loss in oscillating pipes for the safe and reliable operation of ore lifting as well as the design of lifting system. In the present paper, the authors focused on the internal flow in vertical lifting pipe oscillating in the axial direction and carried out slurry transport experiment to investigate the effects of pipe oscillation on the pressure loss. The spherical alumina beads and glass beads were used as the solid particles in the experiment, and the oscillating periods and amplitudes of pipe model as well as the solid concentrations and the mean slurry velocities were varied. The time-averaged components of hydraulic gradient calculated by the prediction method for the steady flow proposed in the past by the authors agreed well with the experimental ones. As for the fluctuating components of hydraulic gradient, the calculation results using a homogeneous mixture model were compared with the experimental data. The comparison result indicated that the homogeneous mixture model would be applicable to the prediction of pressure loss in the vertical pipe oscillating in the axial direction.

Numerical Modeling of Aerated Cavitation Using a Penalization Approach for Air Bubble Modeling Coupled to Homogeneous Equilibrium Model

2014 ◽  
Author(s):  
Petar Tomov ◽  
Sofiane Khelladi ◽  
Christophe Sarraf ◽  
Farid Bakir
Keyword(s):  
Fluid Flow ◽  
Mixture Model ◽  
Stokes Equations ◽  
Saturation Pressure ◽  
Homogeneous Mixture ◽  
Navier Stokes ◽  
Strain Rate Tensor ◽  
Computational Domain ◽  
Time Step ◽  
Homogeneous Mixture Model

Cavitation is a well-known physical phenomena occurring in various technical applications. It appears when the pressure of the liquid drops below the saturation pressure. Coupling aeration in a cavitating flow is a recent technique to control the overall effect of the cavitation. It is achieved by introducing air bubbles into the flow. In order to reveal and explore the behaviour of air gas in the vicinity of the cavitation region, the paper is oriented towards the physics of the colliding vapor phase bubbles and cavitating regions. The re-entrant jet may influence the dynamics of the bubbles as well as the frequency of cavitation separation. Therefore, a two-way coupling between the fluid flow and the introduced vapor is of capital importance. By penalizing the strain rate tensor in the Homogeneous Mixture Model, the two-way coupling has been achieved. The contact-handling algorithm is based on the projections of the velocity fields of the injected particles over the velocity field of the fluid flow. At each time step the gradient of the distance between the bubbles, is kept non-negative as a guarantee of the physical non overlapping. The bubbles’ collisions are considered as inelastic. The differential equations system is composed of the Navier-Stokes equations, implemented with the Homogeneous Mixture Model. A high-order Finite Volume (FV) solver based on Moving Least Squares (MLS) approximations is used. The code uses a SLAU-type Riemann solver for the accurate calculation of the low Mach numbers. The computational domain is a symmetrical 2D venturi duct with an 18°–8° convergent/divergent angles respectively.

FGA-MMF method for the simulation of two-phase flows

2018 ◽  
Vol 35 (3) ◽  
pp. 1161-1182
Author(s):  
Farhang Behrangi ◽  
Mohammad Ali Banihashemi ◽  
Masoud Montazeri Namin ◽  
Asghar Bohluly
Keyword(s):  
Mixture Model ◽  
Continuity Equation ◽  
Second Phase ◽  
Fine Grid ◽  
Content Type ◽  
Multiphase Mixture ◽  
Advection Term ◽  
Mixture Phase ◽  
Phase Mixture ◽  
Multi Phase

Purpose This paper aims to present a novel numerical technique for solving the incompressible multiphase mixture model. Design/methodology/approach The multiphase mixture model contains a set of momentum and continuity equations for the mixture phase, a second phase continuity equation and the algebraic equation for the relative velocity. For solving continuity equation for the second phase and advection term of momentum, an improved approach fine grid advection-multiphase mixture flow (FGA-MMF) is developed. In the FGA-MMF method, the continuity equation for the second phase is solved with higher-order schemes in a two times finer grid. To solve the advection term of the momentum equation, the advection fluxes of the volume fraction in the continuity equation for the second phase are used. Findings This approach has been used in various tests to simulate unsteady flow problems. Comparison between numerical results and experimental data demonstrates a satisfactory performance. Numerical examples show that this approach increases the accuracy and stability of the solution and decreases non-monotonic results. Research limitations/implications The solver for the multi-phase mixture model can only be adopted to solve the incompressible fluid flow. Originality/value The paper developed an innovative solution (FGA-MMF) to find multi-phase flow field value in the multi-phase mixture model. Advantages of the FGA-MMF technique are the ability to accurately determine the phases interpenetrating, decreasing the numerical diffusion of the interface and preventing instability and non-monotonicity in solution of large density variation problems.

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