Separated flow past an airfoil at high angle of attack
LES predictions and analysis
Publication date
2004-04
Document type
Konferenzbeitrag
Author
Jovicic, Nikola
Organisational unit
Institute of Fluid Mechanics, University of Erlangen-Nürnberg
Conference
5th International ERCOFTAC Workshop on Direct and Large-Eddy Simulation ; Munich, Germany ; August 27–29, 2003
Publisher
Springer
Book title
Direct and large-eddy simulation V
First page
611
Last page
618
Peer-reviewed
✅
Part of the university bibliography
Nein
Language
English
Abstract
The objective of this study is the prediction and analysis of the turbulent flow past an unswept wing at high angle of attack. The LES predictions were based on two different subgrid-scale models (Smagorinsky and Dynamic). The Reynolds number (Rec= 105) and the angle of attack ($\alpha$ = 18{\textdegree}) were chosen such that the flow exhibits a trailing-edge separation at the lowest Recrealizable within the corresponding experiment COSTWING. At these operating conditions, many interesting flow phenomena appear, e.g., a thin separation bubble, transition, separation, and large-scale vortical structures. Qualitatively the predictions based on both SGS models show the same aforementioned flow features, although some noteworthy differences become evident, e.g., the shape and size of the separation bubble. This has a strong impact on the transition process and thus the succeeding development of the entire flow yielding quantitative deviations regarding Cp, Cfor k. The differences can be attributed to a well-known shortcoming of the Smagorinsky model. In addition, the paper aims at a deeper insight into the nature of turbulent separated flows. For that purpose the LES data were analyzed according to the anisotropy-invariant theory which provides an improved illustration of what happens in a turbulent flow. Therefore, the anisotropy invariants at various locations in the flow were displayed in the invariant map in order to analyze the state of turbulence in distinct regions.
Cite as
Jovičić, N., Breuer, M. (2004). Separated Flow Past an Airfoil at High Angle of Attack: LES Predictions and Analysis. In: Friedrich, R., Geurts, B.J., Métais, O. (eds) Direct and Large-Eddy Simulation V. ERCOFTAC Series, vol 9. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-2313-2_64
Version
Published version
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