Showing papers in "Computers & Fluids in 1993"

TL;DR: The superiority of the present MUSCL TVD scheme is confirmed by comparison with the results of the ordinary numerical scheme, and the algorithms are relatively simple and the formulas are quite compact.

TL;DR: In this paper, upwind methods for the 1-D Euler equations are reinterpreted as residual distribution schemes, assuming continuous piecewise linear space variation of the unknowns defined at the cell vertices.

TL;DR: A methodology which represents the geometric conservations laws in discrete forms in flow solvers is presented, and the volumetric change of an arbitrarily moving control cell in multidimensions is obtained following the exact solution of thevolumetric increments along the faces.

TL;DR: EURANUS—a general software software system for the simulation of 3-D Reynolds-averaged Navier-Stokes flows about complex geometries, being developed for the European Space Agency for use as a major tool in its aerothermodynamic design work is described.

TL;DR: Computational evidence suggests that least-squares finite element methods for velocity-vorticity-pressure formulations of the incompressible Navier-Stokes equations are, at the least, nearly optimally accurate.

TL;DR: In this paper, a full multigrid/full approximation storage (FMG/FAS) algorithm is used to solve the incompressible recirculating flow problems in complex geometrics.

TL;DR: An incompressible flow solver is described, in which upwind discretizations, implicit relaxation schemes with flux-matrix splitting and a Runge-Kutta time-stepping scheme with multigrid are used.

TL;DR: In this article, the inviscid flow field is computed based on an explicit finite volume method that solves the time-dependent 2D Euler equations linked with the classical nucleation theory and microscopic or macroscopic droplet growth laws.

TL;DR: In this article, the authors evaluated the computational efficiency of three alternative pressure-velocity coupling (viz SIMPLE, PISO, and AVPI) in the calculation of incompressible turbulent flows.

TL;DR: In this article, the Navier-Stokes equations are solved numerically by a fractional step method for the incompressible pulsatile laminar flow in a two-dimensional constricted channel.

TL;DR: In this paper, the Lagrange multipliers are used to derive a system of partial differential equations whose solutions provide the optimal states and controls for boundary control and optimization of a fluid flow.

TL;DR: The cell vertex formulation of the finite volume method is now proving its worth for both the Navier-Stokes and Euler equations, with typical results showing the capability of the method to model boundary layers accurately on coarse and distorted meshes.

TL;DR: In this paper, the generalized scheme of the no-time-counter (NTC) scheme for the direct simulation Monte Carlo method in the analysis of rarefied gas flow is proposed.

TL;DR: Adaptive methods on unsaturated, triangulated grids are considered for solution of the 2-D Euler and Navier-Stokes equations of compressible fluids, and a method based on virtual stretching is presented, which enables anisotropic grid according to the resolution requirements of different criteria.

TL;DR: In this article, two flux-vector splittings are applied to a quasi one-dimensional nozzle flow, using the explicit as well as a semi-implicit Euler scheme with a finite volume upwind formulation.

TL;DR: In this article, a multilevel mathematical formulation for both large-eddy simulation and direct numerical simulation of the compressible turbulence and combusting flows in engines is derived, and then a suitable numerical algorithm is developed.

TL;DR: In this paper, a dynamical multi-block method was used to compute mixing flows in an agitator with paddle impellers and baffles, where the computational domain is divided into two blocks: the inner block containing rotating impellers; and the outer block containing baffles.

TL;DR: In this article, a new turbulence diffusion model which takes into consideration the pressure effect is proposed. But the diffusion model is not suitable for trubulent flows with second-moment closure.

TL;DR: In this article, the influence of shock/shock and shockwave/boundary-layer interactions on the flow past two model configurations, representing critical parts of hypersonic vehicles, is examined.

TL;DR: In this article, a new length scale and dissipation rate for a purely mathematically based algebraic turbulence model derived from renormalization group theory is proposed and tested by applying it to a flat-plate problem to check that a simple shear layer is modeled adequately.

TL;DR: Improvements to an arbitrary high-order time-accurate scheme of δk-form are made by introducing a multi-step procedure which utilizes a scheme parameter and/or with a fourth-order residual averaging technique.

TL;DR: In this article, solution adaptive mesh refinement in three-dimensions on unstructured Delaunay meshes was used to solve the Euler equations for two supersonic flows, one case was uniform flow past a wedge within a channel, producing a shock wave and its reflection off a wall of the channel.

TL;DR: In this paper, a numerical procedure for solving the time-dependent, incompressible Navier-Stokes equations is derived based on the operator-splitting technique, which allows separate operations on each of the variable fields to enable pressure-velocity coupling.

TL;DR: In this paper, a multi-dimensional upwind scheme defined on structured grids is proposed for scalar advection equations and extended to a system of equations along with a conventional one-dimensional approximate Riemann solver.

TL;DR: In this paper, a fully conservative formulation of the conservation equations is presented, which uses a first-order flux-splitting scheme to solve the large system of ordinary differential and algebraic equations resulting from the spatial discretization.

TL;DR: In this article, a 2D VR-7 airfoil with and without a leading edge slat was studied in the water tunnel of the Aeroflightdynamics Directorate, NASA Ames Research Center, where the airfoils were oscillated sinusoidally between 5 and 25 deg at Re = 200,000 to obtain the unsteady lift, drag, and pitching moment data.

TL;DR: This paper presents and analyzes a null-space-free approximate projection method, which is based on cartesian vector components and non-staggered grids and implemented in the computer code HEMO.

TL;DR: The computer code is capable of predicting the mean velocity, solid volume fraction and fluctuation energy profiles, as well as the surface elevation of rapid granular flows in complex geometries of industrial interest.

TL;DR: In this article, a viscous-inviscid interaction scheme is introduced, which implicitly couples the unsteady Euler and the boundary-layer equations, and the adequacy of an integral formulation of the viscous flow equations for use in unstrainedy flows is shown in comparison with experimental results and finite-difference computations, and an explanation is worked out which traces back the unstaky response of the mean and turbulence field due to the external unsteadiness to a quasi-steady behaviour.

TL;DR: The extension of the method originally developed for the Euler equations to include viscous effects, the computation of turbulent flows and the implementation on parallel computers of the scheme on multiblock grids are reviewed.