Numerical Simulations of Turbulent Flow over Airfoils Near and During Static Stall

Ke, Jianghua; Edwards, Jack R.

doi:10.2514/1.c034186

Cited by 18 publications

(8 citation statements)

References 32 publications

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“…There exists some appropriate spanwise cell spacing for which IDDES model works the best. Similar thing also happens in the 3D hybrid LES/RANS simulations of turbulent flow over NACA 0012 airfoil under static stall [24]. This bifurcation like response appears to be driven by the better resolution of energy-containing three-dimensional eddy structures near the front surface with spanwise mesh refinement.…”

Section: Velocity Profiles and Rms Velocity Fluctuationssupporting

confidence: 66%

“…Based on how the blending function works, it is also worth to investigate the performance of different hybrid LES/ RANS models (in this study, Gieseking model, original IDDES model, modified IDDES model) in predicting the turbulent flow features when passing over a square cylinder. Besides, Ke [24] found that when Gieseking model is used for 3D simulations, mesh refinement along spanwise direction doesn't guarantee a solution that is in better agreement with the experimental measurements for turbulent flow at Re = 1,000,000 over a NACA 0012 airfoil under static stall, where the massive separation is involved as well. The effects of spanwise resolution of 3D mesh on the numerical solution of flow over a square cylinder by hybrid LES/RANS simulation are also investigated in this study.…”

Section: Introductionmentioning

confidence: 99%

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RANS and hybrid LES/RANS simulations of flow over a square cylinder

2019

Adv. Aerodyn.

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Unsteady RANS (URANS), hybrid LES/RANS and IDDES simulations were conducted to numerically investigate the velocity field around, and pressures distribution and forces over a square cylinder immersed in a uniform, steady oncoming flow with Reynolds number Re = 21,400. The vortex shedding responses in terms of Strouhal number, the pressure distribution, the velocity profile and the velocity fluctuations obtained by numerical simulations are compared with experimental data. Compared with 2D URANS simulation, 3D simulations using hybrid LES/RANS and IDDES models provide more accurate prediction on the responses in the wake, including mean streamwise velocity profile and rms velocity fluctuations. This also results in more accurate prediction of time-averaged surface pressure coefficient on the rear surface obtained by 3D hybrid LES/RANS and IDDES simulations than by URANS simulation. When a hybrid LES/RANS model or IDDES model is used, a more accurate prediction for either pressure coefficient or velocity profile (especially in the far wake region) is not guaranteed by increasing the mesh resolution along the spanwise direction of the square cylinder.

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Section: Velocity Profiles and Rms Velocity Fluctuationssupporting

confidence: 66%

Section: Introductionmentioning

confidence: 99%

RANS and hybrid LES/RANS simulations of flow over a square cylinder

2019

Adv. Aerodyn.

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“…Unfortunately, there were large discrepancies between the experimental data, F1 and F2, especially for the drag coefficient. When the measurement sensitivity of this transitional flow was considered, the present simulation showed reasonable results similar to previous simulation results [35,36]. It was confirmed that the present simulation adopts adequate methodologies and grid system.…”

Section: Transitional Flow Over Aerospatiale-a Airfoilsupporting

confidence: 88%

“…Figure 6 shows the skin friction coefficient distributions over the upper wall of the airfoil predicted by the deterministic solver with the γ − R θ transition model as well as the comparison with experimental data [32]. The transition point was predicted to be between 10% and 15% of the chord length, which agreed well with other simulation results [35]. The behavior with developing turbulent flow after transition showed consistent results with experimental data.…”

Section: Transitional Flow Over Aerospatiale-a Airfoilsupporting

confidence: 77%

Comparison of the Point-Collocation Non-Intrusive Polynomial (NIPC) and Non-Intrusive Spectral Projection (NISP) Methods for the γ − R θ Transition Model

Nguyen

Chang

2019

Applied Sciences

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In the present work, a comparative study of two major non-intrusive polynomial chaos methods, Point-Collocation Non-Intrusive Polynomial Chaos (NIPC) and Non-Intrusive Spectral Projection (NISP), was conducted for the transitional transitional model. Three multiple model coefficients, Ca2, Ce1, and Ce2 were considered with multiple random inputs with the assumption of uniform distributions with ±10% deviation. The target transitional flows were one around a flat plate and Aerospatiale A-airfoil. Deterministic solutions were obtained by employing the open source software OpenFOAM. The results of two methods were compared to the results of Monte Carlo simulation with 500 runs. The order convergence of the mean value and the standard deviation (STD) were compared in terms of the quantities of interest, drag and lift coefficients. Further, the most effective model coefficient for each transitional flow could be found through the calculation of the Sobol index.

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“…At this Re , a laminar separation bubble is formed at the leading edge prior to stall. Ke and Edwards (2017) carried out simulations of flow past a NACA0012 airfoil under static stall ( Re = 10 6 , Ma = 0.1, AoA = 16.7°) using the Menter’s SST model, Menter–Langtry correlation-based transition model and a hybrid RANS-LES model. It was observed that the leading-edge laminar separation and turbulent reattachment are predicted only when the Menter–Langtry correlation-based transition model is used.…”

Section: Introductionmentioning

confidence: 99%

On the performance of RANS turbulence models in predicting static stall over airfoils at high Reynolds numbers

Nived

Mukesh

Athkuri

et al. 2021

HFF

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Purpose This paper aims to conduct, a detailed investigation of various Reynolds averaged Navier–Stokes (RANS) models to study their performance in attached and separated flows. The turbulent flow over two airfoils, namely, National Advisory Committee for Aeronautics (NACA)-0012 and National Aeronautics and Space Administration (NASA) MS(1)-0317 with a static stall setup at a Reynolds number of 6 million, is chosen to investigate these models. The pre-stall and post-stall regions, which are in the range of angles of attack 0°–20°, are simulated. Design/methodology/approach RANS turbulence models with the Boussinesq approximation are the most commonly used cost-effective models for engineering flows. Four RANS models are considered to predict the static stall of two airfoils: Spalart–Allmaras (SA), Menter’s k – ω shear stress transport (SST), k – kL and SA-Bas Cakmakcioglu modified (BCM) transition model. All the simulations are performed on an in-house unstructured-grid compressible flow solver. Findings All the turbulence models considered predicted the lift and drag coefficients in good agreement with experimental data for both airfoils in the attached pre-stall region. For the NACA-0012 airfoil, all models except the SA-BCM over-predicted the stall angle by 2°, whereas SA-BCM failed to predict stall. For the NASA MS(1)-0317 airfoil, all models predicted the lift and drag coefficients accurately for attached flow. But the first three models showed even further delayed stall, whereas SA-BCM again did not predict stall. Originality/value The numerical results at high Re obtained from this work, especially that of the NASA MS(1)-0317, are new to the literature in the knowledge of the authors. This paper highlights the inability of RANS models to predict the stall phenomenon and suggests a need for improvement in modeling flow physics in near- and post-stall flows.

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Numerical Simulations of Turbulent Flow over Airfoils Near and During Static Stall

Cited by 18 publications

References 32 publications

RANS and hybrid LES/RANS simulations of flow over a square cylinder

RANS and hybrid LES/RANS simulations of flow over a square cylinder

Comparison of the Point-Collocation Non-Intrusive Polynomial (NIPC) and Non-Intrusive Spectral Projection (NISP) Methods for the γ − R θ Transition Model

On the performance of RANS turbulence models in predicting static stall over airfoils at high Reynolds numbers

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