A new calculation of the wake of a flat plate

A new method is presented for the calculation of the wake of a finite flat plate. The method is based upon the recent investigations of the boundary layer near the trailing edge, which led to the triple-deck structure. This multi-layered structure has now been extended to the "classical" wake, which in fact is the continuation of the lowest two layers of the triple-deck. With this new numerical formulation an accuracy of 10-3% can easily be achieved.

Numerical Simulation of a Turbulent Flow in a Channel with Surface Mounted Cubes

In this paper we report on a fourth-order, spectro-consistent simulation of a complex turbulent flow. A spatial discretization of a convection-diffusion equation is termed spectro-consistent if the spectral properties of the convective and diffusive operators are preserved, i.e. convection ↔ skew-symmetric; diffusion ↔ symmetric positive definite. We consider a fully developed flow in a channel, where a matrix of cubes is placed at a wall of the channel. The Reynolds number (based on the channel width and the mean bulk velocity) is equal to Re = 13,000. The three-dimensional flow around the surface mounted cubes has served at a test case at the 6th ERCOFTAC/IAHR/COST workshop on refined flow modeling (Delft, June 1997). Here, mean velocity profiles as well as Reynolds stresses at various locations in the channel have been computed without using any turbulence models. The results agree well with the available experimental data.

Spectro-consistent discretization of Navier-Stokes: a challenge to RANS and LES

In this paper, we discuss the results of a fourth-order, spectro-consistent discretization of the incompressible Navier-Stokes equations. In such an approach the discretization of a (skew-)symmetric operator is given by a (skew-)symmetric matrix. Numerical experiments with spectro-consistent discretizations and traditional methods are presented for a one-dimensional convection-diffusion equation. LES and RANS are challenged by giving a number of examples for which a fourth-order, spectro-consistent discretization of the Navier-Stokes equations without any turbulence model yields better (or at least equally good) results as large-eddy simulations or RANS computations, whereas the grids are comparable. The examples are taken from a number of recent workshops on complex turbulent flows.