A priori and a posteriori analysis of the flow around a rectangular cylinder

Andrea Cimarelli ,Diego Angeli ,Adriano Leonforte ,Matteo Franciolini ,E De Angelis ,Andrea Crivellini

doi:10.1088/1742-6596/923/1/012028

Abstract

The definition of a correct mesh resolution and modelling approach for the Large Eddy Simulation (LES) of the flow around a rectangular cylinder is recognized to be a rather elusive problem as shown by the large scatter of LES results present in the literature. In the present work, we aim at assessing this issue by performing an a priori analysis of Direct Numerical Simulation (DNS) data of the flow. This approach allows us to measure the ability of the LES field on reproducing the main flow features as a function of the resolution employed. Based on these results, we define a mesh resolution which maximize the opposite needs of reducing the computational costs and of adequately resolving the flow dynamics. The effectiveness of the resolution method proposed is then verified by means of an a posteriori analysis of actual LES data obtained by means of the implicit LES approach given by the numerical properties of the Discontinuous Galerkin spatial discretization technique. The present work represents a first step towards a best practice for LES of separating and reattaching flows.

Highlights

In Large Eddy Simulation (LES) the large scales of the flow are directly computed while leaving to the subgrid stresses the duty of accounting for the small unresolved scales
It is interesting to analyse the instantaneous flow features reproduced by the coarse implicit LES simulation (ILES) approach
The flow around a rectangular cylinder is recognized to be challenging for numerical simulations adopting turbulence models as shown by several works in literature, see Bruno et al [2]

Summary

Related content

A priori and a posteriori analysis of the flow around a rectangular cylinder To cite this article: A Cimarelli et al 2017 J. - Large eddy simulation of turbulent cavitating flows A Gnanaskandan and K Mahesh. - Large Eddy Simulation of a Cavitating Multiphase Flow for Liquid Injection M Cailloux, J Helie, J Reveillon et al. - Quantifying variability of Large Eddy Simulations of very large wind farms S J Andersen, B Witha, S-P Breton et al. View the article online for updates and enhancements. View the article online for updates and enhancements This content was downloaded from IP address 131.251.254.61 on 05/07/2018 at 15:44. 35th UIT Heat Transfer Conference (UIT2017) IOP Conf. A Cimarelli, A Leonforte, M Franciolini, E De Angelis, D Angeli and A Crivellini. DIISM, Universita Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy 2 DISMI, Universita di Modena e Reggio Emilia, Via Amendola, 42122 Reggio Emilia, Italy 3 School of Engineering, Cardiff University, Cardiff CF24 3AA, UK

Introduction

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Conclusions