We are concerned with central differencing schemes for solving scalar hyperbolic conservation laws arising in the simulation of multiphase flows in heterogeneous porous media. We compare the Kurganov-Tadmor (KT) (Kurganov and Tadmor, 2000) semi-discrete central scheme with the Nessyahu-Tadmor (NT) (Nessyahu and Tadmor, 1990) central scheme. The KT scheme uses more precise information about the ...

The dependence relation between the macroscopic effective property and the microstructure of interpenetrating multiphase composites is investigated in this paper. The effective elastic moduli of such composites cannot be calculated from conventional micromechanics methods based on Eshelby s tensor because an interpenetrating phase cannot be extracted as dispersed inclusions. Employing the conce...

In this paper we present a new model framework for studying vascular tumour growth, in which the blood vessel density is explicitly considered. Our continuum model comprises conservation of mass and momentum equations for the volume fractions of tumour cells, extracellular material and blood vessels. We include the physical mechanisms that we believe to be dominant, namely birth and death of tu...

To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider ~RHIC!, we have developed a multiphase transport model that includes both initial partonic and final hadronic interactions. Specifically, the Zhang’s parton cascade ~ZPC! model, which uses as input the parton distribution from the heavy ion jet interaction generator ~HIJING! model, is extended to includ...

The state-of-the-art for Direct Numerical Simulation (DNS) of boiling multiphase flows is reviewed, focussing on potential of available computational techniques, the level of current success for their applications to model several basic flow regimes (film, pool-nucleate and wall-nucleate boiling – FB, PNB and WNB, respectively). Then, we discuss multiphysics and multiscale nature of practical b...

The main differences between the deterministic macroscopic models stand in pressure expressions and representation of various phases observed experimentally. Starting from two assumptions, we build a multiphase model that represents macroscopic traffic flow on a single road. The conditions for transition between phases become clear. In addition, a simulation of some scenario are proposed to sup...

This paper presents a way of modelling turbulence in multiphase flows within the context of the Reynolds-Stress Model. The model has been implemented in the general-purpose unstructured finite volume code Fluent V6. Two multiphase turbulence approaches were considered: mixture and dispersed models. The mixture model solves the Reynolds-stress transport equations on the mixture level only. The d...

This article introduces a type of stochastic model, which we call a multiphase stochastic model, for the particle transport in bubbling fluidized beds, making it possible to take into account the finite velocity of fluidization bubbles and also extra particle transport due to "gulf streaming." An extended analysis of experimental results for particle transport in fluidized beds with gulf stream...

The Lattice Boltzmann (LB) method has been shown to be a highly efficient numerical method for solving fluid flow in confined domains such as pipes, irregularly shaped channels or porous media. Traditionally the LB method has been applied to flow in void regions (pores) and no flow in solid regions. However, in a number of scenarios, this may not suffice. That is partial flow may occur in semi-...

This report represents the handouts of an eight hour lecture held on occasion of the ”International Summer School on Computational Modeling of Combustion & Multiphase Flows in Energy Systems”. This summer school took place in Neptun-Olimp, Romania, in the period of July 21 – 25, 2003. The purpose of this report is to give students that are already familiar with the physics and numerical computa...