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
Effects of vortex organization on heat transfer enhancement by Görtler instability
TL;DR: In this paper, the authors investigated the effect of the upstream perturbation wavelength on the heat transfer rate of nonlinear Gortler vortices and showed that the shorter wavelengths of the downstream perturbations increased the heat-transfer rate.
Proceedings ArticleDOI
Receptivity of mach 6 flow over a flared cone to freestream disturbance
TL;DR: In this paper, a numerical simulation study of the receptivity to weak freestream acoustic waves for a Mach 5.941 axisymmetric flow over a flared cone with a 5' half-angle is presented.
Proceedings ArticleDOI
Parametric study on stabilization of hypersonic boundary layer waves using 2-D surface roughness
TL;DR: In this article, an extensive DNS parametric study on the effect of second mode instability from roughness height, width and spacing between roughness elements is conducted, and the results reveal that a taller roughness within one boundary layer thickness height results a stronger damping effect on the second mode.
Journal ArticleDOI
Numerical prediction of unsteady vortex shedding for large leading-edge roughness
Wade W. Huebsch,Alric Rothmayer +1 more
TL;DR: In this article, a full two-dimensional Navier-Stokes algorithm is used to investigate unsteady, incompressible viscous flow past an airfoil leading edge with surface roughness that is characteristic of ice accretion.
Journal ArticleDOI
Influence of Turbulence on Cambered and Symmetrical Airfoils at Low Reynolds Numbers
TL;DR: In this article, small unmanned aerial vehicles (UAVs) are becoming more common as electronic systems decrease in size and weight and these aircraft fly below a Reynolds number of 250,000, where, in clean flow, the wi...
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.