From streaks to spots and on to turbulence: exploring the dynamics of boundary layer transition

TA Zaki - Flow, turbulence and combustion, 2013 - Springer
an eerie type of chaos can lurk just behind a facade of order, and yet deep inside the chaos
lurks an even eerier type of order.” Douglas Hofstadter Bypass transition to turbulence in …

Effect of surface roughness and blade material on the performance of a stationary Savonius wind turbine under different operating conditions

MH Mat Yazik, WS Chang, MHH Ishak, E Fatahian… - Physics of …, 2023 - pubs.aip.org
The Savonius wind turbine is a vertical-axis wind turbine invented in 1930s consisting of a
cylindrical drum with semi-circular blades attached to the drum. It is popular for its simple …

Conditional sampling of transitional boundary layers in pressure gradients

KP Nolan, TA Zaki - Journal of Fluid Mechanics, 2013 - cambridge.org
Statistical analysis of transitional boundary layers in pressure gradients is performed using
the flow fields from direct numerical simulations of bypass transition. Laminar–turbulent …

Streak instabilities in boundary layers beneath free-stream turbulence

MJP Hack, TA Zaki - Journal of fluid mechanics, 2014 - cambridge.org
The 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 …

Görtler instability and transition in compressible flows

D Xu, P Ricco, L Duan - AIAA Journal, 2024 - arc.aiaa.org
We present a discussion on theoretical, experimental, and computational research studies
on Görtler instability and the related transition to turbulence occurring in compressible …

Secondary instabilities of Görtler vortices in high-speed boundary layer flows

J Ren, S Fu - Journal of Fluid Mechanics, 2015 - cambridge.org
Görtler vortices developed in laminar boundary layer experience remarkable changes when
the flow is subjected to compressibility effects. In the present study, five. The subharmonic …

Hypersonic boundary layer transition on a concave wall: stationary Görtler vortices

X Chen, GL Huang, CB Lee - Journal of Fluid Mechanics, 2019 - cambridge.org
This study investigates the stability and transition of Görtler vortices in a hypersonic
boundary layer using linear stability theory and direct numerical simulations. In the …

Wall temperature effects on shock wave/turbulent boundary layer interaction via direct numerical simulation

K Zhu, LX Jiang, WD Liu, MB Sun, QC Wang, ZW Hu - Acta Astronautica, 2021 - Elsevier
Shockwave/turbulent boundary layer interaction on flat plate are investigated by using direct
numerical simulation at different wall temperature of T w/T r= 0.5, 1.0, 2.0 respectively …

Hypersonic boundary layer transition on a concave wall induced by low-frequency blowing and suction

X Chen, J Chen, X Yuan - Physics of Fluids, 2022 - pubs.aip.org
Hypersonic boundary layer transitions caused by unsteady blowing and suction are
investigated with linear stability analyses and direct numerical simulations (DNS). Three …

Direct Numerical Simulation of flow instabilities over Savonius style wind turbine blades

A Ducoin, MS Shadloo, S Roy - Renewable energy, 2017 - Elsevier
Abstract In this paper, Direct Numerical Simulations (DNS) are carried out in order to capture
the flow instabilities and transition to turbulence occurring on a Savonius style wind turbine …