The objective of this article is to review some developments in the use of adjoint equations in
hydrodynamic stability theory. Adjoint-based sensitivity analysis finds both analytical and …

The formation and amplification of streamwise velocity perturbations induced by cross-
stream disturbances is ubiquitous in shear flows. This disturbance growth mechanism, so …

Vertical axis wind turbines (VAWTs) have received growing interest for off-shore application
and in the urban environments mainly due to their omni-directional capability, scalability …

The effect of high levels of free-stream turbulence on the transition in a Blasius boundary
layer is studied by means of direct numerical simulations, where a synthetic turbulent inflow …

Reducing skin friction is important in nature and in many technological applications. This
reduction may be achieved by reducing stresses in turbulent boundary layers, for instance …

In this study we characterize the turbulence, by means of energy spectra, characteristic
turbulence length scales, energy dissipation, kinetic energy decay rate etc., behind a set of …

The flow past a cylinder in proximity to a plane wall is investigated numerically for small gap
ratios. Three vortex dynamic processes associated with different hairpin vortex generation …

It has recently been found by using temporal and spatial numerical simulations that steady
optimal streaks of moderate amplitude, ie, sufficiently large but not exceeding the critical …

Free-stream turbulence (FST) and its effect on boundary-layer transition is an intricate
problem. Elongated unsteady streamwise streaks of low and high speed are created inside …

Direct numerical simulations (DNS) are performed of a transient channel flow following a
rapid increase of flow rate from an initially turbulent flow. It is shown that a low-Reynolds …