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
Analysis of the unstable Tollmien-Schlichting mode on bodies with a rounded leading edge using the parabolized stability equation
M. R. Turner,P. W. Hammerton +1 more
TL;DR: In this paper, the interaction between free-stream disturbances and the boundary layer on a body with a rounded leading edge is considered, and a method which incorporates calculations using the parabolized stability equation in the Orr-Sommerfeld region, along with an upstream boundary condition derived from asymptotic theory in the vicinity of the leading edge, is generalized to bodies with an inviscid slip velocity which tends to a constant far downstream.
Shedding light on the bluff body wake instability
TL;DR: The flow around a vehicle, for example, results in a large resistance and can generate a complex swirl pattern behind the body of the vehicle, which can lead to strong alternating lateral forces as mentioned in this paper.
DissertationDOI
The influence of unsteady streaks on the stability of flat plate boundary layers
TL;DR: In this article, a model is employed to describe the Klebanoff distortions: one Fourier component of the FST is used along with its signature inside the shear region to force the boundary layer and stimulate streaks.
Dissertation
Spatial scales in alluvial channels: on 2d coherent turbulent structures and alternate bars formation
TL;DR: Carrrasco Milian, Aylen as discussed by the authors, et al. Facultad de Ingenieria y Ciencias Hidricas, Argentina.
Journal ArticleDOI
Miniature Vortex Generators for Flow Control in Falkner–Skan Boundary Layers
TL;DR: Vortex generators with heights comparable to displacement thickness are an effective means of producing persistent mean-flow streaks in laminar boundary layers as mentioned in this paper, which can induce streaky base flows.
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.