On the breakdown of boundary layer streaks
Web7 de abr. de 2024 · Görtler vortex-induced hypersonic boundary layer transition controlled by grooves is investigated using direct numerical simulations and spatial bi-global … Web14 de ago. de 2007 · In a flat plate boundary layer, perturbed with streaks, breakdown occurs due to a secondary instability acting on the streaks. An experimental study using a water channel with static turbulence grid revealed the presence of a sinuous secondary instability mode in the bypass transition process. Five sinuous instabilities are …
On the breakdown of boundary layer streaks
Did you know?
Web31 de dez. de 2024 · An analysis is taken on two-dimensional (2D) wall-parallel velocity fields in a smooth-wall turbulent boundary layer with R e τ = 440∼2400, obtained via … Web19 de jul. de 2024 · These streaks induce a flow distortion and lead to a new set of unstable modes. We study the effect of this boundary layer modification using Direct Numerical Simulation (DNS) of a flow at M=6.0 ...
Web1 de abr. de 2024 · [3] Franko K. and Lele S., “ Breakdown Mechanisms and Heat Transfer Overshoot in Hypersonic Zero Pressure Gradient Boundary Layers,” Journal of Fluid Mechanics, Vol. 730, Sept. 2013, pp. 491–532. Webby spanwise spacers inside the boundary layer. This approach is well suited to tackling an apparent controversy in the literature regarding the outcome of the interaction of T-S waves and streaks: some experiments suggest that streaks enhance breakdown in natural transition (Kendall 1998; Boiko et al. 1994), while other experiments indicate
Web29 de out. de 2014 · Brandt, L., Cossu, C., Chomaz, J.M., et al.: On the convectively unstable nature of optimal streaks in boundary layers. Journal of Fluid Mechanics 485, 221–242 (2003) Article MathSciNet MATH Google Scholar Brandt, L.: Numerical studies of the instability and breakdown of a boundary-layer low-speed streak. Webbations developing on boundary layer streamwise streaks. These elongated structures and their breakdown are found to be key factors both in transition in boundary layers …
Web4 de jun. de 2024 · The effectiveness of streak modes in controlling the oblique-type breakdown in a supersonic boundary-layer at Mach 2.0 is investigated using direct …
WebThis paper aims at characterizing the bypass transition in boundary layers subject to strong pressure gradient and curvature effects. A series of highly resolved large-eddy … crystal\u0027s crWebThe secondary instability of boundary layer streaks is investigated by means of direct stability analysis. The base flow is computed in direct simulations of bypass transition. The random nature of the free-stream perturbations causes the formation of a spectrum of streaks inside the boundary layer, with breakdown to turbulence crystal\\u0027s cozy kitchenWebThis is followed by their breakdown through a process known as the lift-up mechanism (Kline et al., 1967), where negative perturbation streaks rise within the boundary layer. The external high-frequency disturbances, which are limited in their penetration, provide excitation for the growth of an outer instability leading to turbulent breakdown of the streak. crystal\u0027s craftiesWeb8 de abr. de 2010 · An estimation of streak amplitude based on the modulation of the instantaneous boundary layer thickness is proposed. … dynamic hypothesis nlpWeb1 de jan. de 2007 · When the jet velocity is low, some vortices appear in the boundary layer, but the transition of the boundary layer does not take place. However, when the … dynamic hysteresishttp://www.diva-portal.org/smash/record.jsf?pid=diva2:319582 crystal\\u0027s country cream mount erieWeb18 de set. de 2013 · Douglas Hofstadter Bypass transition to turbulence in boundary layers is examined using linear theory and direct numerical ... On the breakdown of boundary layer streaks. J. Fluid Mech. 428, 29–60 (2001) Article MathSciNet MATH Google Scholar Barkley, D., Blackburn, H.M., Sherwin, S.J.: Direct optimal growth analysis for ... dynamic hypertext markup language