Infinite Swept-Wing Navier-Stokes Computations with eN Transition Prediction.

AIAA Journal ◽  
2005 ◽  
Vol 43 (6) ◽  
pp. 1221-1229 ◽  
Author(s):  
Hans W. Stock
Keyword(s):  
Navier Stokes ◽  
Swept Wing ◽  
Transition Prediction

Secondary instability of crossflow vortices and swept-wing boundary-layer transition

1999 ◽  
Vol 399 ◽  
pp. 85-115 ◽  
Author(s):  
MUJEEB R. MALIK ◽  
FEI LI ◽  
MEELAN M. CHOUDHARI ◽  
CHAU-LYAN CHANG
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Three Dimensional ◽  
Finite Amplitude ◽  
Secondary Instability ◽  
Boundary Layer Transition ◽  
Swept Wing ◽  
Layer Transition ◽  
Transition Prediction ◽  
Dimensional Boundary

Crossflow instability of a three-dimensional boundary layer is a common cause of transition in swept-wing flows. The boundary-layer flow modified by the presence of finite-amplitude crossflow modes is susceptible to high-frequency secondary instabilities, which are believed to harbinger the onset of transition. The role of secondary instability in transition prediction is theoretically examined for the recent swept-wing experimental data by Reibert et al. (1996). Exploiting the experimental observation that the underlying three-dimensional boundary layer is convectively unstable, non-linear parabolized stability equations are used to compute a new basic state for the secondary instability analysis based on a two-dimensional eigenvalue approach. The predicted evolution of stationary crossflow vortices is in close agreement with the experimental data. The suppression of naturally dominant crossflow modes by artificial roughness distribution at a subcritical spacing is also confirmed. The analysis reveals a number of secondary instability modes belonging to two basic families which, in some sense, are akin to the ‘horseshoe’ and ‘sinuous’ modes of the Görtler vortex problem. The frequency range of the secondary instability is consistent with that measured in earlier experiments by Kohama et al. (1991), as is the overall growth of the secondary instability mode prior to the onset of transition (e.g. Kohama et al. 1996). Results indicate that the N-factor correlation based on secondary instability growth rates may yield a more robust criterion for transition onset prediction in comparison with an absolute amplitude criterion that is based on primary instability alone.

scholarly journals Database Approach for Laminar-Turbulent Transition Prediction: Navier–Stokes Compatible Reformulation

AIAA Journal ◽  
2017 ◽  
Vol 55 (11) ◽  
pp. 3648-3660 ◽  
Author(s):  
Guillaume Bégou ◽  
Hugues Deniau ◽  
Olivier Vermeersch ◽  
Grégoire Casalis
Keyword(s):  
Navier Stokes ◽  
Transition Prediction ◽  
Turbulent Transition ◽  
Laminar Turbulent Transition

Numerical and experimental transition prediction on a realistic laminar swept wing

2017 ◽  
Vol 96 (1) ◽  
pp. 63-74
Author(s):  
D. G. Romano ◽  
D. de Rosa ◽  
R. S. Donelli
Keyword(s):  
Swept Wing ◽  
Transition Prediction ◽  
Experimental Transition

scholarly journals A class of exact Navier–Stokes solutions for homogeneous flat-plate boundary layers and their linear stability

2014 ◽  
Vol 752 ◽  
pp. 462-484 ◽  
Author(s):  
Michael O. John ◽  
Dominik Obrist ◽  
Leonhard Kleiser
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Linear Stability ◽  
Boundary Layers ◽  
Stokes Equations ◽  
Plate Boundary ◽  
Navier Stokes ◽  
Transition Prediction ◽  
Neutral Curves ◽  
Tollmien Schlichting

AbstractWe introduce a new boundary layer formalism on the basis of which a class of exact solutions to the Navier–Stokes equations is derived. These solutions describe laminar boundary layer flows past a flat plate under the assumption of one homogeneous direction, such as the classical swept Hiemenz boundary layer (SHBL), the asymptotic suction boundary layer (ASBL) and the oblique impingement boundary layer. The linear stability of these new solutions is investigated, uncovering new results for the SHBL and the ASBL. Previously, each of these flows had been described with its own formalism and coordinate system, such that the solutions could not be transformed into each other. Using a new compound formalism, we are able to show that the ASBL is the physical limit of the SHBL with wall suction when the chordwise velocity component vanishes while the homogeneous sweep velocity is maintained. A corresponding non-dimensionalization is proposed, which allows conversion of the new Reynolds number definition to the classical ones. Linear stability analysis for the new class of solutions reveals a compound neutral surface which contains the classical neutral curves of the SHBL and the ASBL. It is shown that the linearly most unstable Görtler–Hämmerlin modes of the SHBL smoothly transform into Tollmien–Schlichting modes as the chordwise velocity vanishes. These results are useful for transition prediction of the attachment-line instability, especially concerning the use of suction to stabilize boundary layers of swept-wing aircraft.

Automatic Transition Prediction in a Navier–Stokes Solver Using Linear Stability Theory

AIAA Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Jan-Sören Fischer ◽  
Bambang I. Soemarwoto ◽  
Edwin T. A. van der Weide
Keyword(s):  
Linear Stability ◽  
Stability Theory ◽  
Linear Stability Theory ◽  
Navier Stokes ◽  
Transition Prediction
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