Inducing spanwise motions in the vicinity of solid boundaries alters energy, mass and/or momentum transfer. Under some conditions, these are such that drag is reduced transition to turbulence delayed. There several possibilities induce those motions, be it through active imposition a predefined velocity distribution at walls or by careful design wall shape, which corresponds passive control.In ...

In this work, we perform numerical simulation of fluid mixing in a floor-grooved micro-channel with wavy sidewalls which may impose perturbation on the helical flow induced by the slanted grooves on the channel floor. The perturbation is caused by separation vortices in the recesses of the wavy-walled channel as the Reynolds number is large enough. The results show that the effects of the wavy ...

We report a novel illusion--curvature blindness illusion: a wavy line is perceived as a zigzag line. The following are required for this illusion to occur. First, the luminance contrast polarity of the wavy line against the background is reversed at the turning points. Second, the curvature of the wavy line is somewhat low; the right angle is too steep to be perceived as an illusion. This illus...

The interaction of an impinging oblique shock wave with angle 30° and a supersonic turbulent boundary layer at Ma?=2.9 Re? = 2400 over wavy-wall is investigated through direct numerical simulation compared the on flat-plate under same flow conditions. A sinusoidal amplitude to wavelength ratio 0.26 moves in streamwise direction uniformly distributed across spanwise direction. influences interac...

We describe the application of a gravity wave-generating technique to certain higher dimensional black holes. We find that the induced waves generically destroy the event horizon producing parallelly propagated curvature singularities. Based on a talk presented at the Seventh Canadian Conference on General Relativity and Relativistic Astrophysics in Calgary, AB, Canada, May 31 – June 7, 1997. E...

In this study, the effect of thermal radiation on micro-polar fluid flow over a wavy surface is studied. The optically thick limit approximation for the radiation flux is assumed. Prandtl’s transposition theorem is used to stretch the ordinary coordinate system in certain directions. The wavy surface can be transferred into a calculable plane coordinate system. The governing equations of micro-...

Turbulence structure on the gas side of a wavy stratified flow was experimentally investigated in a near horizontal 18.7 cm (H) 10 cm (W) 5.5m (L) rectangular duct.By applying the Variable Interval Time Averaging (VITA) technique to the hot wire anemometer measurements frequency of occurrence of turbulent events were detected near the air-water interface. Experimental results showed that fr...

A morphological type of Sarcocystis cysts found in one of two examined great black-backed gull, Larus marinus (Linnaeus) (Laridae), is considered to represent a new species for which the name Sarcocystis lari sp. n. is proposed and its description is provided. The cysts are ribbon-shaped, very long (the largest fragment found was 6 mm long) and relatively narrow (up to 75 microm). Under a light...

Reduction of Mach wave emission from a dual-stream jet is modeled via a linear temporal analysis in the frame of reference of the jet instability. The interface between the primary and secondary streams is simulated by a exible wavy wall with zero phase speed and arbitrary growth rate. The interface between the secondary and ambient streams is simulated by a vortex sheet. The secondary stream, ...

Development of counter-rotating streamwise vortices in a rectangular channel with onesided wavy surface has been experimentally quantified using hot-wire anemometry. The wavy surface has fixed amplitude of 3.75 mm. The counter-rotating vortices are pre-set by means of a sawtooth pattern cut at the leading edge of the wavy surface. Variations of the central streamwise velocity Uc with a channel ...