Jorg Franke

Large eddy simulation of the flow past a circular cylinder at ReD=3900

A large eddy simulation (LES) is performed for the turbulent flow around a circular cylinder at Re D = 3900 with a cell-centered finite volume code that solves the compressible Navier-Stokes equations. The results are compared with the direct numerical simulation of Ma et al. (J. Fluid Mech. 410 (2000) 29) and the experiments of Ong and Wallace (Exp. Fluids 20 (1996) 441). It is shown that short averaging times, which have been used by several previous LES do not lead to converged mean values. For the largest averaging time used in this study, the results are in good agreement with the aforementioned data. In addition, the realizability of the modeled subgrid scale stresses and the computed Reynolds stresses is analyzed.

COST 732 in practice: the MUST model evaluation exercise

The aim of this paper is to describe the use of a general methodology tailored to the evaluation of micro-scale meteorological models applied to flow and dispersion simulations in urban areas. This methodology, developed within COST 732, has been tested through a large modelling exercise involving many groups across Europe. The major test case used is the Mock Urban Setting Test (MUST) experiment representing an idealised urban area. It is emphasised that a full model evaluation is problem-dependent and requires several activities including a statistical validation that requires a careful choice of the metrics for the comparison with measurements.

Introduction to the Prediction of Wind Loads on Buildings by Computational Wind Engineering (CWE)

In this chapter the numerical prediction of wind loads on buildings as a branch of Computational Wind Engineering (CWE) is introduced. First the different simulation approaches are described with their corresponding basic equations and the necessary turbulence models. The numerical solution of the systems of equations is sketched and the most important aspects and their influence on the computational results are highlighted.

Towards a model evaluation protocol for urban scale flow and dispersion models

This paper reports on the stages forming a model evaluation protocol for urban flow and dispersion models proposed within the COST Action 732 on “Quality Assurance and Improvement of Micro-Scale Meteorological Models”. It discusses the different components forming model evaluation with emphasis on validation and implementation of the protocol for the test case Mock Urban Setting Test (MUST). The protocol was proposed with building-resolving models in mind, but integral models have also been included. The suggested approach can be used for further micro-scale model evaluation and for the standardisation of their applications.