摘要:

This paper will give an overview of wavelet methods applied to computational fluid dynamics, including scale resolution, grid and order selection throughout a domain. In addition, Spline-based wavelet methods will be placed in the context of finite elements where the element size is adjusted throughout the domain.

ISSN:1061-8562    

DOI:10.1080/10618569808961690

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Numerical simulations of a very small amplitude acoustic wave interacting with a shock wave in a quasi-ID convergent-divergent nozzle is performed using an unstructured finite volume algorithm with piece-wise linear, least square reconstruction, Roe flux difference splitting, and second-order MacCormack time marching. First, the spatial accuracy of the algorithm is evaluated for steady flows with and without the normal shock by running the simulation with a sequence of successively finer meshes. Then the accuracy of the Roe flux difference splitting near the sonic transition point is examined for different reconstruction schemes. Finally, the unsteady numerical solutions with the acoustic perturbation are presented and compared with linear theory results.

ISSN:1061-8562    

DOI:10.1080/10618569808961691

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A new parallelization method is proposed for factored alternating direction implicit (ADI) schemes based on the vectorized global domain directional sweep. This approach, when combined with multi-partitioning domain decomposition, significantly reduces the frequency of necessary communication calls and minimizes processor idling during the sweeping processes. The present parallelization approach is applied to a number of vectorized two-dimensional compressible Navier-Stokes solvers. The codes vary in complexity from laminar to algebraic turbulence closure model and finally the strongly coupled Navier-Stokes and K-e equations. Implementation is conducted using PVM (Parallel Virtual Machine) message passing tool on the Cray T3D massively parallel processing (MPP) machine. The implemented parallel codes are assessed in terms of accuracy and parallel performance.

ISSN:1061-8562    

DOI:10.1080/10618569808961692

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

This paper deals with the numerical treatment of Eulerian approach for dilute two-phase compressible flows (gas-particles mixtures) in axisymmetric configurations. For dilute flows, two classes of models depending on the dispersed phase volumetric fraction can be found. The volume occupied by the particles may be considered, that yields a model in which the gas phase and the dispersed phase equations are coupled through the void fraction and the source terms (Delhaye model). The void fraction effects can be neglected, that means the gas phase is a carrier phase for the particles (Ishii model). The mathematical nature of the two models is demonstrated from analysis of characteristic directions. For the Delhaye's model, a centered scheme is used to solve the system of partial differential equations, while an upwind TVD scheme is used for the Ishii's one. Then, it is shown that the problem of symmetry boundary conditions does not depend on the physical approach, as long as the flow remains dilute. However, a classical treatment for symmetry boundary conditions at the geometrical axis leads to large errors. A particular treatment for this boundary is presented: a new class of particles, described by a supplementary system of equations, is required.

ISSN:1061-8562    

DOI:10.1080/10618569808961693

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The time-dependent nonlinear problem on a cylinder suspension by a thin inviscid liquid jet is solved numerically. A new conservative free-lagrange method has been applied. The stable oscillating motion of a cylinder was obtained in a range of problem parameters.

ISSN:1061-8562    

DOI:10.1080/10618569808961694

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor