Journal ArticleDOI
Boundary-layer receptivity to freestream disturbances
TLDR
The boundary-layer receptivity to external acoustic and vortical disturbances is reviewed in this article. But, the authors do not consider the effects of external acoustic or vortic disturbances on the boundary layer.Abstract:
The current understanding of boundary-layer receptivity to external acoustic and vortical disturbances is reviewed. Recent advances in theoretical modeling, numerical simulations, and experiments are discussed. It is shown that aspects of the theory have been validated and that the mechanisms by which freestream disturbances provide the initial conditions for unstable waves are better understood. Challenges remain, however, particularly with respect to freestream turbulenceread more
Citations
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Journal ArticleDOI
Influence of a weak adverse pressure gradient on the generation of tonal protuberance noise in a laminar boundary layer
TL;DR: In this paper, the authors examined the influence of the weak adverse pressure gradient on the critical protuberance height for the onset of tonal noise, and found that the strong adverse pressure gradients could cause the critical perturbation height to decrease, while the frequencies of tonality were little changed in the present experimental condition.
Journal ArticleDOI
Identification of free-stream and boundary layer correlating events in free-stream turbulence-induced transition
TL;DR: In this paper , an extended proper orthogonal decomposition (E-POD) procedure is applied to particle image velocimetry (PIV) data to identify correlating events between the free-stream velocity field and transitional boundary layers for flow configurations typical of low-pressure turbine blades.
Proceedings ArticleDOI
The effect of wavepacket frequency bandwidth on the laminar-turbulent transition process in a Blasius boundary layer
Kean Lee Kang,Khoon Seng Yeo +1 more
TL;DR: In this paper, it was shown that wide bandwidth signals caused the wavepacket to transition to turbulence via the subharmonic route, whereas narrow bandwidth led to transition through Klebanoff modes (streaks).
Proceedings ArticleDOI
Experimental Investigation of the Tonal Self-Noise Emission of a Vehicle Side Mirror
Journal ArticleDOI
Local structure of boundary layer transition in experiments with a single streamwise vortex
K. V. Manu,J Dey,Joseph Mathew +2 more
TL;DR: In this paper, the transition induced by an isolated streamwise vortex embedded in a flat plate boundary layer was studied experimentally, where the vortex was created by a gentle hill with a Gaussian profile that spanned on half of the width of the flat plate mounted in a low turbulence wind tunnel.
References
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Book
Stability and Transition in Shear Flows
TL;DR: In this article, the authors present an approach to the Viscous Initial Value Problem with the objective of finding the optimal growth rate and the optimal response to the initial value problem.
Journal ArticleDOI
A note on an algebraic instability of inviscid parallel shear flows
TL;DR: In this paper, it was shown that all parallel inviscid shear flows of constant density are unstable to a wide class of initial infinitesimal three-dimensional disturbances in the sense that, according to linear theory, the kinetic energy of the disturbance will grow at least as fast as linearly in time.
Journal ArticleDOI
Parabolized stability equations
TL;DR: Parabolized stability equations (PSE) have been used for aerodynamic design of laminar flow control systems as discussed by the authors, and they can be obtained at modest computational expense.
Journal ArticleDOI
Optimal disturbances and bypass transition in boundary layers
TL;DR: In this article, the authors used the steady boundary-layer approximation to calculate the upstream disturbances experiencing maximum spatial energy growth, which are numerically calculated using techniques commonly employed when solving optimal-control problems for distributed parameter systems.
Journal ArticleDOI
Reynolds number independent instability of the boundary layer over a flat surface : optimal perturbations
TL;DR: In this article, the dependence on initial conditions of the three-dimensional algebraic spatial instability of the Blasius boundary layer is examined by a recently developed method of receptivity analysis based on the upstream integration of adjoint equations.