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Dynamic stall of an oscillating wing. Part 1: Evaluation of turbulence modelsUnsteady flowfields of a two-dimensional oscillating wing are calculated using an implicit, finite-difference, Navier-Stokes numerical scheme using five widely used turbulence models. The objective of this study is to identify an appropriate turbulence model for accurate simulation of three-dimensional dynamic stall. Three unsteady flow conditions corresponding to attached flow, light-stall, and deep-stall of an oscillating wing experiment were chosen as test cases for computations. Results of unsteady airload hysteresis curves, harmonics of unsteady pressures, and instantaneous flow pictures are presented. Comparison of unsteady airloads with experiment show that all models are deficient in some sense and not a single model predicts all airloads consistently and in agreement with experiment for all flow conditions. For the attached flow condition, the Renormalization Group Theory (RNG), the Johnoson-King (J-K), and the Spalart-Allmaras (S-A) models have better performance. The Baldwin-Lomax (B-L) and the Baldwin-Barth (B-B) models fair poorly. At the light-stall condition, the results for the RNG, the J-K, and S-A models are in agreement with experiment for the upstroke but they all over predict the separation shown by the experiment and therefore have bigger hysteresis loops than experimental results. The B-B model results are also in good agreement for upstroke but have poor lift hysteresis for downstroke. It has superior drag and pitching-moment predictions. For deep-stall conditions, the airloads for the RNG, the B -B, and the S-A models have fair agreement with experiment, but the B-B model performed better at the extreme deep-stall condition. Overall, the RNG model provides significant improvement over the B-L model in all flow regimes with no additional computational cost. The Baldwin-Barth model is the most expensive of the models considered here, costing about 2.5 times that of the Baldwin-Lomax model. Finally, a brief discussion of the effects of grid density, time-step size, and numerical dissipation on the unsteady solutions are also presented.
Document ID
19950028585
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Srinivasan, G. R.
(JAI Associates, Inc. Mt. View, CA, United States)
Ekaterinaris, J. A.
(Navy-NASA Joint Inst. of Aeronautics, Moffett Field, CA United States)
Mccroskey, W. J.
(US Army Aeroflight dynamics DirectoratMoffett Field, Moffett Field, CA United States)
Date Acquired
August 16, 2013
Publication Date
August 9, 1993
Subject Category
Aerodynamics
Report/Patent Number
AIAA PAPER 93-3403
Accession Number
95A60184
Funding Number(s)
CONTRACT_GRANT: DAAL03-90-C-0013
Distribution Limits
Public
Copyright
Other

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