Supersonic laminar flow control techniques investigated within the SUPERTRAC project

The global objective of the SUPERTRAC project is to explore the possibilities to delay laminar-turbulent transition on supersonic aircraft wings. The following techniques are investigated: micron-sized roughness elements, anti-contamination devices, suction and shape optimization. This paper provides an overview of the project and describes in...

Prediction of bypass transition with Differential Reynolds stress models

Orientation on quantitative IR-thermography in wall-shear stress measurements

Flow measurements for an afterbody in a vertical wind tunnel

Vertical structure of the flow due to waves and currents - Laser-doppler flow measurements for waves following or opposing a current

Changes in the mean horizontal-velocity profile in combined wave-current motion, outside the bottom boundary-layer, are essential for the correct prediction of cross-shore sediment transport outside the surf zone and the transport of dissolved matter, e.g. Klopman (1992). To be able to verify mathematical and numerical models (see Klopman, 1992)...

Some properties of the Langevin model for dispersion

The Langevin Equation is used to describe dispersion of pollutants in the atmosphere. The theoretical background for the equation is discussed in length and a review on previous treatments and applications is given. It is shown that the Langevin equation can describe dispersion in complex circumstances. In particular the equation is applied to...

Interactions between wavemaking and the boundary layer and wake of a ship model

A detailed experimental study has been conducted in a towing tank on a 3.048-meter-long mathematical model, known as the Wigley hull, to study the effects of viscosity on the wavemaking resistance of the ship form. The measurements included total resistance, viscous resistance, pressure distribution, and boundary-layer measurements of the model...

The Turbulent Wave Boundary Layer: A theoretical study

Close to the bottom the no-slip condition will retard the flow and cause a boundary layer to develop. In nature this boundary layer will for most practical purposes be turbulent and the bed will be rough. Usually the boundary layer is confined to a thin layer close to the bed having a typical thickness of 0.2 m under surface gravity waves. The...

Free-Surface Boundary Layer and the Origin of Bow Vortices

The boundary layer that exists due to the boundary conditions at a curved free surface of a viscous liquid ahead of a body in motion is analyzed. It is shown that surface tension and viscous effects are important and together explain the occurrence of vortices which have been observed on ship bows. The equations of the free-surface boundary...

Accuracy and reliability aspects of thin boundary layer calculations

Applications of a high-order finite-difference method to the solution of the boundary layer equations

Memory Effect in a Turbulent Boundary-Layer Flow Due to a Relatively Strong Axial Variation of the Mean-Velocity Gradient

Measurements have been made of the distributions of mean velocity, turbulence intensities and turbulence shear-stress in a turbulent boundary-layer downstream of a hemi-spherical cap attached onto the plane rigid wall. The eddy-viscosity, when computed in the classical way according to Boussinesq's concept from the lateral gradient of the mean...