Wall-Modeled Large-Eddy Simulation of Transonic Airfoil Buffet at High Reynolds Number

Fukushima, Yuma; Kawai, Soshi

doi:10.2514/1.j056537

Cited by 100 publications

(49 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Secondly, the unsteadiness captured in Fig. 5a is not harmonic as previously seen for the RBC12 aircraft [19] or in 2D studies for the OAT15A aerofoil [9][10][11][12][13][14][15][16]. Although not shown here, the drag coefficient, C D , and pitching moment coefficient, C M , exhibit similar patterns.…”

Section: Global Forces and Surface Samplingsupporting

confidence: 61%

“…With advancing technology, the use of Computational Fluid Dynamics (CFD) in shock-buffet prediction has increased substantially in the last two decades. The 2D experimental results for the OAT15A aerofoil [8] have been used for validation in a series of CFD studies in which the Unsteady Reynolds-averagedNavier-Stokes (URANS), Large Eddy Simulations (LES), and hybrid RANS-LES approaches have been applied [9][10][11][12][13][14][15][16]. The variation in results presented revealed that there is still an uncertainty in prediction of shock-buffet by means of URANS, particularly when closed with eddyviscosity-based turbulence models.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Unsteady shock front waviness in shock-buffet of transonic aircraft

Apetrei

Ciobaca²,

Curiel-Sosa

et al. 2020

Adv. Aerodyn.

View full text Add to dashboard Cite

The unsteady transonic aerodynamics of a wing-body configuration is investigated by solving the Unsteady Reynolds-averaged Navier-Stokes equations closed with the full Reynolds Stress Model. This work presents the prediction of flow field characteristics during deep shock-buffet penetration of a transport aircraftrepresentative geometry. Mach number of 0.85, and Reynolds number of 5 million based on the mean chord, are selected to reproduce experimental test conditions that serve as validating datasets. The results obtained give information about both surface and flow field shock-buffet dynamics. An unsteady shock front is observed on the suction side of the wing which gives birth to the so-called buffet cells. Flow field characteristics are dominated by the presence of lambda-shaped shocks and fully separated boundary layer over a significant part of the wing.

show abstract

Section: Global Forces and Surface Samplingsupporting

confidence: 61%

mentioning

confidence: 99%

Unsteady shock front waviness in shock-buffet of transonic aircraft

Apetrei

Ciobaca²,

Curiel-Sosa

et al. 2020

Adv. Aerodyn.

View full text Add to dashboard Cite

show abstract

“…Similar observations were made with DES, but the ZDES predicted the buffet onset at the same incidence as the experiments. To further reduce the impact of modeling, Large Eddy Simulations (LES) have been carried out by Garnier and Deck [16] and Fukushima and Kawai [17]. In summary, URANS simulations are able to reproduce the main features of two-dimensional buffet, but simulation of the turbulent scales might be required to reduce the impact of the turbulence modeling.…”

Section: Introductionmentioning

confidence: 99%

Similitude between 3D cellular patterns in transonic buffet and subsonic stall

Plante¹,

Dandois²,

Laurendeau

2019

AIAA Scitech 2019 Forum

View full text Add to dashboard Cite

This paper studies the similitude between the 3D cellular patterns which appears in the simulation of transonic buffet and subsonic stall phenomenon using RANS/URANS simulations. These wings are obtained from the extrusion of a 2D airfoil with an added sweep angle and periodic boundary conditions imposed at both ends. This numerical setup allows to study three-dimensional buffet on the simplest configuration possible. Numerical solutions exhibit three-dimensional flows in the form of buffet cells. The latter are convected towards the wing tip when a sweep angle is added leading to the superposition of two frequencies. The first one is independent of the sweep angle and is characteristic of two-dimensional buffet. The second one increases with the sweep angle and is related to the convection of the buffet cells. These cells are reminiscent of the stall cells which are well-known but for low speed flow conditions. Solutions of the URANS equations for infinite swept wings in stall conditions at low speed are computed showing the same convection of the cellular patterns. These results lead us to think the discrepancies between 2D and 3D buffet are caused by the appearance of stall cells, which are the same as buffet cells, and not from a modification of the shock wave boundary layer interaction.

show abstract

“…In the transonic buffet simulation, detached eddy simulation (DES) [1,[47][48][49] and large eddy simulation (LES) [12] series turbulence models can predict three-dimensional buffet flow fields. However, it is not practical to compute various upstream conditions by using DES or LES turbulence models to determine buffet onset boundaries because these methods require a grid resolution that is much higher than that for URANS simulations, resulting in excessively longer computational times.…”

Section: Numerical Methods and Validationmentioning

confidence: 99%

“…These Mach numbers fall in the typical transonic flow range; consequently, unsteady shockwave/boundary layer interactions could induce intensive, large-scale, unsteady lift, and transonic buffet will be the result [4][5][6][7][8][9][10]. This transonic buffet not only decreases riding comfort [10][11][12], but structural fatigue could also be triggered, and disastrous accidents could even result [2,4,9,[13][14][15]. Thus, transonic buffet is deemed one of the most important factors limiting the flight envelope [2,7,9,14,16,17], since a margin of 30% on the lift coefficient at cruising conditions must be respected by design standards [7].…”

Section: Introductionmentioning

confidence: 99%

Postponing the Onset and Alleviating the Load of Transonic Buffet by Using Steady and Periodic Tangential Slot Blowing

et al. 2019

View full text Add to dashboard Cite

Transonic buffet not only influences the structural integrity, handling quality and ride comfort, but also limits the flight envelope of transporters and airliners. To delay buffet onset and alleviate the buffet load, the effects of both steady and periodic tangential slot blowing are investigated. The results show that steady tangential blowing on the airfoil upper surface can postpone the buffet onset margin and evidently increase the lift coefficient at incidence angles near and above the buffet onset case of the clean airfoil. Under buffeting conditions of the clean airfoil, unsteady aerodynamic loads can be greatly suppressed by both steady and periodic blowing. The control effort is depicted as reduced wedge effect and weakened dynamic effect. The buffet mechanism includes (a) the feedback loop between the Kutta wave and the separation bubble under the shock foot, and (b) the interaction between the shear layer shed by the shockwave and Kutta waves. Under blowing conditions, the upstream creeping Kutta waves are prevented, and the intensity of the shear layer shed by the shockwave into separated flows is evidently reduced. Parametric studies show that the control effect is reduced as the blowing slot moves downstream, and steady blowing at 41% x/c is the most favorable control case.

show abstract

Wall-Modeled Large-Eddy Simulation of Transonic Airfoil Buffet at High Reynolds Number

Cited by 100 publications

References 46 publications

Unsteady shock front waviness in shock-buffet of transonic aircraft

Unsteady shock front waviness in shock-buffet of transonic aircraft

Similitude between 3D cellular patterns in transonic buffet and subsonic stall

Postponing the Onset and Alleviating the Load of Transonic Buffet by Using Steady and Periodic Tangential Slot Blowing

Contact Info

Product

Resources

About