Subsonic flow past three-dimensional localised heating elements in boundary layers

Passive control of transition in three-dimensional boundary layers, with emphasis on discrete roughness elements.

A brief review of laminar flow control techniques is given and a strategy for achieving laminarization for transonic transport aircraft is discussed. A review of some flight-test results on swept-wing transition is presented. It is also shown that polished leading edges can create large regions of laminar flow because the flight environment is relatively turbulence free and the surface finish r...

outflow Boundary Codition Issues in Direct Numerical Simulation of Three- Dimensional Plane Wake Flow

Three-dimensional transverse instabilities in detached boundary layers

The direct numerical simulation of the incompressible Navier-Stokes equations of the flow above a bump shows a stationary longitudinal instability at a Reynolds number of Re = 400. A three-dimensional global mode linear analysis is used to interpret these results and shows that the most unstable eigenmode is steady and localized in the recirculation bubble, with spanwise wavelength of approxima...

Aero Optics of Subsonic Boundary Layers over Backward Steps

An experimental study of the two-dimensional transition from turbulent boundary layer over small backward-facing steps is presented in order to investigate the effect of the separation bubble behind the back-step on the aero-optical environment, as well as to demonstrate the capacity for characterizing complex flow fields using non-intrusive optical measurement techniques such as the Malley Pro...

Investigation of suction for laminar flow control of three-dimensional boundary layers

Direct numerical simulations are employed to investigate the effects of discrete suction orifices at the wall on the disturbance evolution in laminar three-dimensional boundary-layer flows with favourable pressure gradient. Suction panels with many suction orifices can excite unstable crossflow (CF) modes even if the orifice spacing is smaller than the chordwise/spanwise wavelengths of unstable...