Compressible Linear Stability of Confluent Wake/Boundary Layers

AIAA Journal ◽  
2003 ◽  
Vol 41 (12) ◽  
pp. 2349-2356 ◽  
Author(s):  
William W. Liou ◽  
Fengjun Liu
Keyword(s):  
Linear Stability ◽  
Boundary Layers

Linear stability of supersonic cone boundary layers

AIAA Journal ◽  
1992 ◽  
Vol 30 (10) ◽  
pp. 2402-2410 ◽  
Author(s):  
Greg Stuckert ◽  
Helen Reed
Keyword(s):  
Linear Stability ◽  
Boundary Layers

scholarly journals Effect of Pressure Gradient on the Development of Görtler Vortices

2019 ◽  
Author(s):  
Leandro Marochio Fernandes ◽  
Marcio Teixeira de Mendonça
Keyword(s):  
Pressure Gradient ◽  
Linear Stability ◽  
Boundary Layers ◽  
Adverse Pressure Gradient ◽  
Base Flow ◽  
Linear Stability Theory ◽  
Wave Number ◽  
Local Mode ◽  
Effect Of Pressure ◽  
Centrifugal Instability

Boundary layers over concave surfaces may become unstable due to centrifugal instability that manifests itself as stationary streamwise counter rotating vortices. The centrifugal instability mechanism in boundary layers has been extensively studied and there is a large number of publications addressing different aspects of this problem. The results on the effect of pressure gradient show that favorable pressure gradients are stabilizing and adverse pressure gradient enhances the instability. The objective of the present investigation is to complement those works, looking particularly at the effect of pressure gradient on the stability diagram and on the determination of the spanwise wave number corresponding to the fastest growth. This study is based on the classic linear stability theory, where the parallel boundary layer approximation is assumed. Therefore, results are valid for Görtler numbers above 7, the lower limit where local mode linear stability analysis was identified in the literature as valid. For the base flow given by the Falkner-Skan solution, the linear stability equations are solved by a shooting method where the eigenvalues are the Görtler number, the spanwise wavenumber and the growth rate. The results show stabilization due to favorable pressure gradient as the constant amplification rate curves are displaced to higher Görtler numbers, with the opposite effect for adverse pressure gradient. Results previously unavailable in the literature identifying the fastest growing mode spanwise wavelength for a range of Falkner-Skan acceleration parameters are presented.

Simplified linear stability transition prediction method for separated boundary layers

AIAA Journal ◽  
1992 ◽  
Vol 30 (8) ◽  
pp. 1953-1961 ◽  
Author(s):  
Paolo Dini ◽  
Michael S. Selig ◽  
Mark D. Maughmer
Keyword(s):  
Linear Stability ◽  
Boundary Layers ◽  
Prediction Method ◽  
Transition Prediction

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.

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