Experimental studies of surface waves inside a cylindrical container

Abstract

We experimentally investigate the dynamics of surface waves excited by oscillations from a cylindrical sidewall. Particle-imaging-velocimetry measurements with fluorescent particles were used to determine the flow patterns near the sidewall of the cylindrical fluid container and to identify the locations of the evolving air–water interfaces. The high-frequency wall oscillations created four jets that originate at the cylindrical sidewall. Four vortex streets shed from the jets propagate from the sidewall to the centre of the container and subsequently excite a low-frequency gravity wave. The interaction between this gravitational surface wave and the high-frequency capillary waves was found to be responsible for creating droplet splash at the water surface. This phenomenon was first described as ‘Long-Xi’ or ‘dragon wash’ in ancient China. The physical processes for generating the droplet ejection, including the circular capillary waves, azimuthal waves, streaming jets and low-frequency gravity waves, are described in this paper.

Transition in Hypersonic Boundary Layers: Role of Dilatational Waves

“…Particle image velocimetry (PIV) is one of the most powerful techniques to obtain an instantaneous flowfield in a plane or volume. Our previous experience with PIV has been reported in References [14,30,[42][43][44]. Because of fast developments in chargedcouple device (CCD) cameras since the first application of PIV in hypersonic flows [45], this technique is now capable of investigating high-speed flows [46].…”

“…Our previous experience with PIV has been reported in [14,[42][43][44]. Because of fast developments in CCD cameras since the first application of PIV in hypersonic flows [45], this technique is now more commonly used in high-speed flows.…”

Experimental investigation of freely falling thin disks. Part 1. The flow structures and Reynolds number effects on the zigzag motion

“…The laser beam passed through a set of lenses that formed a 1 mm thick light sheet. The technique was the same as used by Lee et al (2011). The tracer particles were ∼10 µm in diameter with a density of 1.07 g cm −3 so they followed the flow very well when dispersed in water.…”

Bounds for the blow-up time of a porous medium equation with weighted nonlocal source and inner absorption terms

“…Equation (1) describes the diffusion of concentration of some Newtonian fluids through porous medium or the density of some biological species in many physical phenomena and biological species theories (cf. [1][2][3][4][5][6]). It has been known that the nonlocal source term presents a more realistic model for population dynamics, see [1][2][3].…”