Royal Dutch Meteorological Institute; Ministery Of Infrastructure And The Environment

Publications, presentations and other activities
The measurement of U, V and uv inside the turbulent spot using conditionally sampled hot-wire anemometer signals
1989
by Bosveld (KNMI), Haren (NIOZ, The Netherlands), Absil (ASW Research Centre, La Spezia, Italy),

By means of a tripping wire turbulent spots are generated in a conditionally stable laminar boundary layer along a flat plate in a low-turbulence windtunnel. At several vertical and lateral positions the streamwise (U) and vertical (V) velocity components of the spot are measured using anX-shaped hot wire anemometer. The spot's leading edge (LE) and trailing edge (TE) are determined by a high frequency detection criterion.

The derived ensemble averaged shear stress 〈uv〉 shows a remarkable plateau over the last 3/4 of the spot length and over about 1/2 of the spot width, approximately independent of the height above the plate. The measurements suggest that the velocities of the LE and the TE can be explained by simple advection of the active turbulent region. Other mechanisms seem to be responsible for the lateral spread of the spot, as is suggested by the measurements outside the plane of symmetry.

Bibliographic data
Bosveld, Haren and Absil, The measurement of U, V and uv inside the turbulent spot using conditionally sampled hot-wire anemometer signals
Flow, Turbulence and Combustion, 1989, 46, 291-307.
Abstract (html)