摘要:

A cellular automaton leading to self-propagating fronts in a discrete fluid has been implemented. In spite of the stabilizing diffusive-convective mechanisms, planar propagation of these fronts becomes unstable due to a feed-back mechanism with the flow generated by the front itself. The stability properties have been analyzed in the continuum limit and compared with the discrete simulations as well as with the stability properties of premixed flame fronts.

ISSN:0041-1450    

DOI:10.1080/00411459408203861

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper presents a bidimensional cellular model for simulating lava flows and its application to the simulation of the 1986–87 and 1991–92 Etnean eruptions.

ISSN:0041-1450    

DOI:10.1080/00411459408203862

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Simulations of Rayleigh-Bénard convection have been carried out using molecular dynamics methods. This article focuses on the different kinds of time-dependent roll structure observed in studies of soft-and hard-disk fluids. In both cases periodic oscillations were observed, but despite similar imposed conditions the periods and amplitudes differed significantly. Such behavior suggests that the two fluids are not at the same state point as far as the convection is concerned.

ISSN:0041-1450    

DOI:10.1080/00411459408203863

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The paper is concerned with the justification of Monte Carlo simulation schemes for the solution of nonlinear kinetic equations via time averaging. Some results obtained recently about systematic errors inherent to these methods are reviewed. Sufficient criteria for their validity are derived, and tools reducing the effect of particle correlations are presented.

ISSN:0041-1450    

DOI:10.1080/00411459408203864

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

By means of Burgers' equation it is shown that a recently proposed stochastic formulation of fluid dynamics allows for a new approach to numerical studies of hydrodynamic fluctuations. The new formulation describes the velocity field as the expectation value of a discrete stochastic process governed by a multivariate master equation. With the help of a systematic expansion it is demonstrated that the fluctuations of this discrete stochastic process correspond to those predicted by the theory of fluctuating hydrodynamics. Stochastic simulations of shock waves are presented and stress the practical relevance of the new technique.

ISSN:0041-1450    

DOI:10.1080/00411459408203865

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Atomic simulations of shock waves in gases have been performed using both molecular dynamics and the direct simulation Monte Carlo method devised for the Boltzmann equation. The profiles of the fluid density, velocity and temperature computed across the shock are shown to agree with the Navier-Stokes description for weak shocks (Mach numbers ranging up to 2) but then on the discrepancy increases with the Mach number. The Burnett modification to the Navier-Stokes equations is compared to the simulation results .

ISSN:0041-1450    

DOI:10.1080/00411459408203866

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

In this paper we present parallel algorithms for molecular dynamics and lattice gas simulations for hydrodynamics phenomena at the microscopic level. Characteristics of the algorithms (execution time, efficiency and speedup) are shown for the transputer networks and for the networks of SUN SPARC and IBM RS/6000 workstations. Some of the results are compared with those obtained on the iPSC/860 multiprocessor computer.

ISSN:0041-1450    

DOI:10.1080/00411459408203867

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A numerical method for solving the Boltzmann equation is proposed. This method is based on a finite difference scheme for the approximation of the collision kernel and a finite element scheme for the transport phase. The properties of the Boltzmann equation are also satisfied in our method.

ISSN:0041-1450    

DOI:10.1080/00411459408203868

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The turbulent mixing of both inert and reactive scalar fields is investigated. Single-point moment formulations outline the closure problems related to the molecular diffusion and the chemical source terms. The external supply of a characteristic decay time is avoided by including the scalar-gradient in the formulation, but then the straining/rotation, scalar dissipation and scalar-gradient dissipation must be approximated. The scalar probability density function (PDF) approach treats exactly the reaction rate term but modelling of the diffusive transport is required. The joint PDF equation of one scalar and its gradient must also model the straining/rotation term. Inert and reactive scalars are simulated using existing approximations in the form of deterministic or stochastic models. A new closure is tested with the characteristic scalar-decay time expressed as a function of the scalar-gradient. The equations are numerically solved with a Monte Carlo technique and predictions are compared with available direct numerical simulation (DNS) results.

ISSN:0041-1450    

DOI:10.1080/00411459408203869

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The expansion of steam from states in the upper surroundings of the saturation curve to states under this curve is simulated by the finite volume method. Main attention is given to the description of the condensation rate and droplet growth in molecular free flow.

ISSN:0041-1450    

DOI:10.1080/00411459408203870

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor