A comparative study of DES type methods for mild flow separation prediction on a NACA0015 airfoil
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 6 November 2017
Abstract
Purpose
The purpose of this paper is to numerically investigate the mildly separated flow phenomena on a near-stall NACA0015 airfoil, by using Detached-Eddy Simulation (DES) type methods. It includes a comparison of different choices of underlying Reynolds-averaged Navier–Stokes model as well as subgrid-scale stress model in Large-Eddy simulation mode.
Design/methodology/approach
The unsteady flow phenomena are simulated by using delayed DES (DDES) and improved DDES (IDDES) methods, with an in-house computational fluid dynamics solver. Characteristic frequencies in different flow regions are extracted using fast Fourier transform. Dynamic mode decomposition (DMD) method is applied to uncover the critical dynamic modes.
Findings
Among all the DES type methods investigated in this paper, only the Spalart–Allmaras-based IDDES captures the separation point as measured in the experiments. The classical vortex-shedding and the shear-layer flapping modes for airfoil flows with shallow separation are also found from the IDDES results by using DMD.
Originality/value
The value of this paper lies in the assessment of five different DES-type models through the detailed investigation of the Reynolds stresses as well as the separation and reattachment.
Keywords
Acknowledgements
This work was supported by the National Key Basic Research Program of China (2014CB744801), the EU-China Joint Project MARS (266326), the NSFC Grants 11572177, 51376106 and 11272183 and the Tsinghua University initiative Scientific Research Program (2014z21020).
Citation
Wang, L., Li, L. and Fu, S. (2017), "A comparative study of DES type methods for mild flow separation prediction on a NACA0015 airfoil", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 27 No. 11, pp. 2528-2543. https://doi.org/10.1108/HFF-07-2016-0263
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited