Acoustical Measurements of Air Bubbles Bursting at a Water Surface: Bursting Bubbles as Helmholtz Resonators

1992 ◽  
Vol 97 (C7) ◽  
pp. 11443-11452 ◽  
Author(s):  
Donald E. Spiel
Keyword(s):  
Water Surface ◽  
Air Bubbles ◽  
Helmholtz Resonators

Contact angle of air bubbles attached to an air-water surface in foam applications

Langmuir ◽  
1990 ◽  
Vol 6 (5) ◽  
pp. 995-1001 ◽  
Author(s):  
L. A. Lobo ◽  
A. Nikolov ◽  
A. Dimitrov ◽  
P. Kralchevski ◽  
D. T. Wasan
Keyword(s):  
Contact Angle ◽  
Water Surface ◽  
Air Bubbles

Fluid Dynamics of Hydrophilous Pollination in Ruppia (Widgeon Grass)

2016 ◽  
Author(s):  
Naga Musunuri ◽  
Ian Fischer ◽  
Pushpendra Singh ◽  
Daniel E. Bunker ◽  
Susan Pell
Keyword(s):  
Fluid Dynamics ◽  
Aquatic Plants ◽  
Water Surface ◽  
Pollen Dispersal ◽  
Pollen Grain ◽  
Air Bubbles ◽  
Ruppia Maritima ◽  
Two Dimensional ◽  
Brackish Waters ◽  
Hydrophilous Pollination

The aim of this work is to understand the physics underlying the mechanisms of two-dimensional aquatic pollen dispersal, known as hydrophily, that have evolved in several genera of aquatic plants, including Halodule, Halophila, Lepilaena, and Ruppia. We selected Ruppia maritima, which is native to salt and brackish waters circumglobally, for this study. We observed two mechanisms by which the pollen released from male inflorescences of Ruppia is adsorbed on a water surface: 1) inflorescences rise above the water surface and after they mature their pollen mass falls onto the surface as clumps and disperses as it comes in contact with the surface; 2) inflorescences remain below the surface and produce air bubbles which carry pollen mass to the surface where it disperses. In both cases dispersed pollen masses combined with others under the action of lateral capillary forces to form pollen rafts. The formation of porous pollen rafts increases the probability of pollination since the attractive capillary force on a pollen raft toward a stigma is much larger than on a single pollen grain. The presence of a trace amount of surfactant can disrupt the pollination process as the pollen is not captured or transported on the water surface.

Irregular Bubble Entrainment Following Drop Impact on a Free Surface

2003 ◽  
Author(s):  
Yukio Tomita ◽  
Toshiyasu Kasai ◽  
Shinya Miura
Keyword(s):  
Free Surface ◽  
Impact Velocity ◽  
Water Surface ◽  
Drop Impact ◽  
Drop Diameter ◽  
Air Bubbles ◽  
Air Bubble ◽  
Bubble Entrainment ◽  
Irregular Case ◽  
The Impact

An air bubble is entrained by the impact of a drop on a water surface. Consequently sound is emitted. There are two categories of the bubble entrainment depending on the drop diameter dD and impact velocity Vimp. One is the regular entrainment where air bubbles are always pinched off, another is the irregular case where bubbles are trapped irregularly. In this paper we explore the mechanism of the irregular bubble entrainment and induced bubble sound.

Dispersion of Spilled Heavy Oil by Impinging Water Jet

2007 ◽  
Author(s):  
Akinori Iwasaki ◽  
Hiroharu Kato
Keyword(s):  
Heavy Oil ◽  
Natural Environment ◽  
Water Surface ◽  
High Speed ◽  
Detrimental Effect ◽  
Water Jet ◽  
Air Bubbles ◽  
High Speed Camera ◽  
Counter Flow ◽  
Guide Plate

The purpose of this study is searching for a new method of dispersing spilled heavy oil, which has a detrimental effect on the natural environment and the ecosystem of the sea. A method ejecting a water jet vertically downward to heavy oil on the water surface was discussed. The water jet involved the heavy oil and the minute air bubbles, and passed the nozzle of the guide plate. The shapes of the nozzles of the guide plates were three types; a conventional column, a 5 times length column, and a taper. The dispersion efficiency of the taper type nozzle was the best among three. The flow in the nozzle of the three guide plates were recorded by a high-speed camera. From the high-speed moves, the occurrence of two flows, regular and counter flow, was suspected in the taper guide plate. In addition, it seemed that the two flows occurred the sharing force between the minute air bubbles. It is considered that the sharing force invent the surplus efficiency of disperse.

scholarly journals Does the kinorhynch have a hydrophobic body surface? Measurement of the wettability of a meiobenthic metazoan

2016 ◽  
Vol 3 (10) ◽  
pp. 160512 ◽  
Author(s):  
Daisuke Ishii ◽  
Hiroshi Yamasaki ◽  
Ryosuke Uozumi ◽  
Euichi Hirose
Keyword(s):  
Contact Angle ◽  
Body Surface ◽  
Water Surface ◽  
Aquatic Invertebrates ◽  
Anterior Part ◽  
The Body ◽  
Surface Measurement ◽  
Air Bubbles ◽  
Hydrophilic Surface

The body surface of aquatic invertebrates is generally thought to be hydrophilic to prevent the attachment of air bubbles. In contrast, some interstitial invertebrates, such as kinorhynchs and some crustaceans, have a hydrophobic body surface: they are often trapped at the water surface when the sediment in which they reside is mixed with air and water. Here, we directly measured the wettability of the body surface of the kinorhynch Echinoderes komatsui , using a microscopic contact angle meter. The intact body surface of live specimens was not hydrophobic, but the anterior part was less hydrophilic. Furthermore, washing with seawater significantly decreased the wettability of the body surface, but a hydrophilic surface was recovered after a 1 h incubation in seawater. We believe that the hydrophobic cuticle of the kinorhynch has a hydrophilic coat that is readily exfoliated by disturbance. Ultrastructural observations supported the presence of a mucus-like coating on the cuticle. Regulation of wettability is crucial to survival in shallow, fluctuating habitats for microscopic organisms and may also contribute to expansion of the dispersal range of these animals.

Surface breakup and air bubble formation by drop impact in the irregular entrainment region

2007 ◽  
Vol 588 ◽  
pp. 131-152 ◽  
Author(s):  
Y. TOMITA ◽  
T. SAITO ◽  
S. GANBARA
Keyword(s):  
Froude Number ◽  
Water Column ◽  
Water Surface ◽  
Bubble Formation ◽  
Drop Impact ◽  
Air Bubbles ◽  
Bubble Generation ◽  
Air Bubble ◽  
Bubble Entrainment ◽  
The Impact

Drop impact on a water surface can be followed by underwater sounds originating not at the drop impact but when the entrained bubbles oscillate. Although the sound mechanism in the regular bubble entrainment region is well-known, there is less knowledge on the impact phenomena in the irregular bubble entrainment region where various situations can exist, such as many types of bubble formation or even no bubble generation under some conditions. In the present study, the aim is to clarify the dynamics of the water surface after the impact of a primary drop, mainly with diameter 5.2, 5.7 and 6.2mm, each of which is accompanied by a single satellite drop. Special attention was paid to the breakup behaviour of the water surface for Froude number Fr < 300. It was found that three underwater sounds were generated for a single drop impact, besides the sound due to impact itself. The first two were audible to the human ear, but the third one was almost inaudible. The first underwater sound resulted from the oscillation of a single air bubble formed as a result of the satellite drop impact on the bottom of the contracting cavity, and the second sound was due to the oscillation of air bubbles generated during the collapse of the water column. The formation of these air bubbles strongly depends on the Froude number, Weber number (or Bond number) and the aspect ratio of the drop at impact, although involving probability characteristics. Furthermore it is suggested that an air bubble entrapped in a water column plays an important role in increasing the probability of contact between the column surface and the curved free surface. A Japanese Suikinkutsu was introduced as an application of drop-impact-induced sounds. Using an open-type Suikinkutsu an additional experiment was carried out with larger drops with average diameters of 6.2, 7.2 and 7.8, mm.

scholarly journals A simple technique for growing large, optically “perfect” ice crystals

1996 ◽  
Vol 42 (142) ◽  
pp. 585-587 ◽  
Author(s):  
Charles A. Knight
Keyword(s):  
Small Angle ◽  
Water Surface ◽  
Simple Technique ◽  
Supercooled Water ◽  
Ice Crystals ◽  
Air Bubbles ◽  
Ice Crystal ◽  
Spontaneous Formation ◽  
Temperature Controlled ◽  
Simple Growth

AbstractLarge, single ice crystals containing nо air bubbles and free of both small-angle grain boundaries and visible stress birefringence can be grown using a very simple growth chamber within a temperature-controlled, outer enclosure. The method relies upon the spontaneous formation of an ice crystal with its с axis accurately normal to a free, slightly supercooled, water surface.

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