Journal ArticleDOI
The form drag of two-dimensional bluff-plates immersed in turbulent boundary layers
Malcolm Good,Peter N. Joubert +1 more
TLDR
In this paper, the authors measured the distributions of pressure on a bluff flat plate (fence) correlated with the characteristics of the smooth-wall boundary layer in which it is immersed, and found that the relative extent of upstream influence of the bluff-plate on the boundary layer was found to increase rapidly as h/δ decreases.Abstract:
Measurements of the distributions of pressure on a bluff flat plate (fence) have been correlated with the characteristics of the smooth-wall boundary layer in which it is immersed. For zero pressure-gradient flows, correlations are obtained for the variation of form drag with plate height h which are analogous in form to the ‘law of the wall’ and the ‘velocity-defect law’ for the boundary-layer velocity profile. The data for adverse pressure-gradient flows is suggestive of a ‘law of the wake’ type correlation. Pressures on the upstream face of the bluff-plate are determined by a wall-similarity law, even for h/δ > 1, and are independent of the pressure-gradient history of the flow; the separation induced upstream is apparently of the Stratford-Townsend type. The effects of the history of the boundary layer are manifested only in the flow in the rear separation bubble, and then only for h/δ > ½. The base pressure is also sensitive to free-stream pressure gradients downstream of the bluff-plate. The relative extent of upstream influence of the bluff-plate on the boundary layer is found to increase rapidly as h/δ decreases. One set of measurements of the mean flow field is also presented.read more
Citations
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Journal ArticleDOI
The flow around a surface-mounted cube in uniform and turbulent streams
Ian P. Castro,A. G. Robins +1 more
TL;DR: In this article, an experimental investigation of the flow around surface mounted cubes in both uniform, irrotational and sheared, turbulent flows is described, and comparisons with the somewhat sparse measurements of previous workers are made and the relevance of recent theoretical attempts to describe the flow, as opposed to numerical calculation techniques to predict it, is briefly discussed.
Journal ArticleDOI
The Flow Around Surface-Mounted, Prismatic Obstacles Placed in a Fully Developed Channel Flow (Data Bank Contribution)
R. Martinuzzi,Cameron Tropea +1 more
TL;DR: In this paper, the flow field around surface-mounted, prismatic obstacles with different spanwise dimensions was investigated using the crystal violet, oil-film and laser-sheet visualization techniques as well as by static pressure measurements.
Journal ArticleDOI
The reattachment and relaxation of a turbulent shear layer
Peter Bradshaw,F. Y. F. Wong +1 more
TL;DR: In this article, the authors show that the splitting of the shear layer at reattachment, where part of the flow is deflected upstream into the recirculating flow region to supply the entrainment, causes a pronounced decrease in eddy length scale, evidently because the larger eddies are torn in two.
Journal ArticleDOI
An outline of the techniques available for the measurement of skin friction in turbulent boundary layers
TL;DR: In this article, the authors discuss force-measurement balances, the use of the velocity profile, pressure measurements by surface pitot tubes or about obstacles, and the analogies of heat transfer, mass transfer or surface oil flow.
Journal ArticleDOI
Wind protection by model fences in a simulated atmospheric boundary layer
J.K. Raine,D.C. Stevenson +1 more
TL;DR: A brief review of windbreak aerodynamics is presented and tests of model shelter fences in a simulated atmospheric boundary layer are described in this article, where measurements of mean wind velocity, RMS velocity fluctuations and energy spectra for the streamwise velocity component were made in the lee of model fences of permeability 0, 20, 34% and 50%.
References
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Journal ArticleDOI
The law of the wake in the turbulent boundary layer
TL;DR: In this paper, the authors proposed to represent the mean-velocity profile by a linear combination of two universal functions, namely the law of the wall and the wake, and compared the results with experimental data.
Book ChapterDOI
The Turbulent Boundary Layer
TL;DR: In this article, the authors examined the effect of roughness on boundary layer characteristics and showed that the wall is aerodynamically smooth for a turbulent boundary layer if the roughness elements are so small as to be buried in the laminar sublayer.
Journal ArticleDOI
Calibration of the Preston tube and limitations on its use in pressure gradients
TL;DR: In this paper, it is shown that in sufficiently strong favorable and adverse pressure gradients the inner-law velocity distribution breaks down completely, and it is suggested that this breakdown is associated with reversion to laminar flow.
Journal ArticleDOI
The prediction of separation of the turbulent boundary layer
TL;DR: In this article, the concept of a turbulent inner layer with zero wall stress is put forward, and it is deduced that in the neighbourhood of the wall the velocity is proportional to the square root of the distance from the wall.
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