Results 221 to 230 of about 23,990 (264)
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AIChE Journal, 1975
AbstractDrag reduction by dilute solutions of linear, random‐coiling macromolecules in turbulent pipe flow is reviewed. The experimental evidence is emphasized in three sections concerned with the graphical display of established features of the phenomenon, data correlation and analysis, and the physical mechanism of drag reduction.
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AbstractDrag reduction by dilute solutions of linear, random‐coiling macromolecules in turbulent pipe flow is reviewed. The experimental evidence is emphasized in three sections concerned with the graphical display of established features of the phenomenon, data correlation and analysis, and the physical mechanism of drag reduction.
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Journal of Fluid Mechanics, 2009
Two types of wall actuation in channel flow are considered: travelling waves of wall deformation (peristalsis) and travelling waves of blowing and suction. The flow response and its mechanisms are analysed using nonlinear and weakly nonlinear computations.
Hœpffner, Jérôme, Fukagata, Koji
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Two types of wall actuation in channel flow are considered: travelling waves of wall deformation (peristalsis) and travelling waves of blowing and suction. The flow response and its mechanisms are analysed using nonlinear and weakly nonlinear computations.
Hœpffner, Jérôme, Fukagata, Koji
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AIAA Journal, 1981
It is shown that the mechanisms of forebody drag reduction by means of either a spike or a forward-facing jet are similar, with the maximum achievable drag reduction being of the same order. Because the jet may be a relatively cool gas, however, the forward facing jet has the additional capability of reducing the aerodynamic heating that is so severe ...
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It is shown that the mechanisms of forebody drag reduction by means of either a spike or a forward-facing jet are similar, with the maximum achievable drag reduction being of the same order. Because the jet may be a relatively cool gas, however, the forward facing jet has the additional capability of reducing the aerodynamic heating that is so severe ...
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Progress in Aerospace Sciences, 1975
Abstract The present paper gives a review of various existing methods for reducing base drag of two-dimensional and axisymmetric bodies having a blunt base. These methods include splitter plates, both thin and thick, splitter wedges, base bleed. boat-tailing and various types of serrated trailing edges.
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Abstract The present paper gives a review of various existing methods for reducing base drag of two-dimensional and axisymmetric bodies having a blunt base. These methods include splitter plates, both thin and thick, splitter wedges, base bleed. boat-tailing and various types of serrated trailing edges.
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The Importance of Drag Reduction
Aircraft Engineering and Aerospace Technology, 1936THE contents of a technical journal such as AIRCRAFT ENGINEERING are of necessity indicative of current thought. Its pages at any given time reflect the problems that are confronting designers and the doubts that may be perplexing them. At the same time, they give a picture of the manner in which progress is being made and the order in which various ...
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1981
Abstract : A study is being made of the effect on aerodynamic drag of boundary layer irradiation by radioactive sources. A blow-down wind tunnel and a skin friction drag balance have been designed and constructed. The balance is of the null-position type, and is operated using an automatic control system to maintain the null position of the drag plate.
J. Clark +3 more
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Abstract : A study is being made of the effect on aerodynamic drag of boundary layer irradiation by radioactive sources. A blow-down wind tunnel and a skin friction drag balance have been designed and constructed. The balance is of the null-position type, and is operated using an automatic control system to maintain the null position of the drag plate.
J. Clark +3 more
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Annual Review of Fluid Mechanics, 1969
An examination is made of the experimental evidence for the reduction of skin friction in dilute solutions of high molecular weight linear polymers below that of the solvent alone. Inferences are drawn about the necessary properties of the polymers and their solvents, and the mechanical properties of the solutions are described.
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An examination is made of the experimental evidence for the reduction of skin friction in dilute solutions of high molecular weight linear polymers below that of the solvent alone. Inferences are drawn about the necessary properties of the polymers and their solvents, and the mechanical properties of the solutions are described.
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The Canadian Journal of Chemical Engineering, 1980
AbstractDrag reduction in turbulent pipe flow by means of boundary and centerline injection of long hair‐like asbestos fibers has been investigated. Pressure drop and mean velocity profiles were measured at various Reynolds numbers and injection rates in order to study some mechanistic aspects of drag reduction in water‐fiber and polymer‐fiber systems.
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AbstractDrag reduction in turbulent pipe flow by means of boundary and centerline injection of long hair‐like asbestos fibers has been investigated. Pressure drop and mean velocity profiles were measured at various Reynolds numbers and injection rates in order to study some mechanistic aspects of drag reduction in water‐fiber and polymer‐fiber systems.
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On the mechanism of drag reduction
Journal of Non-Newtonian Fluid Mechanics, 1995Recent studies indicate that growing streamwise perturbations driven by streamwise vortices and the resulting Reynolds stresses play a significant role in both the transition to turbulence and the near-wall turbulent flow. In this note, we show that viscoelasticity introduces a negative feedback, so that the streamwise flow driven by a streamwise ...
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Bio-inspired drag reduction: From nature organisms to artificial functional surfaces
Giant, 2020Chunhui Zhang +2 more
exaly