Investigation of a lattice Boltzmann model with a variable speed of sound

A lattice Boltzmann model is considered in which the speed of sound can be varied independently of the other parameters. The range over which the speed of sound can be varied is investigated and good agreement is found between simulations and theory. The onset of nonlinear effects due to variations in the speed of sound is also investigated and good agreement is again found with theory. It is also shown that the fluid viscosity is not altered by changing the speed of sound

Direct simulation of liquid-gas-solid flow with a free surface lattice Boltzmann method

Direct numerical simulation of liquid-gas-solid flows is uncommon due to the considerable computational cost. As the grid spacing is determined by the smallest involved length scale, large grid sizes become necessary -- in particular if the bubble-particle aspect ratio is on the order of 10 or larger. Hence, it arises the question of both feasibility and reasonability. In this paper, we present a fully parallel, scalable method for direct numerical simulation of bubble-particle interaction at a size ratio of 1-2 orders of magnitude that makes simulations feasible on currently available super-computing resources. With the presented approach, simulations of bubbles in suspension columns consisting of more than $100\,000$ fully resolved particles become possible. Furthermore, we demonstrate the significance of particle-resolved simulations by comparison to previous unresolved solutions. The results indicate that fully-resolved direct numerical simulation is indeed necessary to predict the flow structure of bubble-particle interaction problems correctly.Comment: submitted to International Journal of Computational Fluid Dynamic

Simulating quantum mechanics on a quantum computer

Algorithms are described for efficiently simulating quantum mechanical systems on quantum computers. A class of algorithms for simulating the Schrodinger equation for interacting many-body systems are presented in some detail. These algorithms would make it possible to simulate nonrelativistic quantum systems on a quantum computer with an exponential speedup compared to simulations on classical computers. Issues involved in simulating relativistic systems of Dirac and gauge particles are discussed.Comment: 22 pages LaTeX; Expanded version of a talk given by WT at the PhysComp '96 conference, BU, Boston MA, November 1996. Minor corrections made, references adde

Some preliminary results on a high order asymptotic preserving computationally explicit kinetic scheme

In this short paper, we intend to describe one way to construct arbitrarily high order kinetic schemes on regular meshes. The method can be arbitrarily high order in space and time, run at least CFL one, is asymptotic preserving and computationally explicit, i.e., the computational costs are of the same order of a fully explicit scheme. We also introduce a non linear stability method that enables to simulate problems with discontinuities, and it does not kill the accuracy for smooth regular solutions

Flood Routing Based on Diffusion Wave Equation Using Lattice Boltzmann Method

AbstractOne-dimensional diffusion wave equation is a simplified form of the full Saint Venant equations by neglecting the inertia terms. In this study, the Lattice Boltzmann method for the linear diffusion wave equation was developed. In order to verify the calculation accuracy of it, the analytical solution and Muskingum method were also introduced. Excellent agreement was obtained between observed data and numerical prediction. The results show that the Lattice Boltzmann method is a very competitive method for solving diffusion wave equation in terms of computational efficiency and accuracy