scholarly journals A bubble entrainment by a small refrigerant drop impact on water surface

2011 ◽  
Vol 31 (7) ◽  
pp. 27-32 ◽  
Author(s):  
Hisanobu Kawashima ◽  
Ryota Shibasaki ◽  
Tsuneaki Ishima
Keyword(s):  
Water Surface ◽  
Drop Impact ◽  
Bubble Entrainment

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.

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 Experimental Study of Drop Impact on Deep-Water Surface in the Presence of Wind

2018 ◽  
Vol 48 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Xinan Liu
Keyword(s):  
Deep Water ◽  
Water Surface ◽  
Water Drop ◽  
Threshold Value ◽  
Impact Angle ◽  
Drop Impact ◽  
Wind Speeds ◽  
Secondary Droplets ◽  
Low Wind Speeds ◽  
The Impact

AbstractThe effects of wind on the impact of a single water drop on a deep-water surface are studied experimentally in a wind tunnel. Experiments are performed by varying impacting drop diameters, ranging from 2.5 to 4.1 mm and wind speeds up to 6.7 m s−1. The sequence of splashing events that occurred during drop impacts is recorded with a backlit, cinematic shadowgraph technique. The experimental results show that for low wind speeds, an asymmetrical crown forms on the leeward of the periphery of the colliding region after the drop hits the water surface, while a wave swell forms on the windward. Secondary droplets are generated from the crown rim. For high wind speeds with large drop diameters, ligaments are generated from the crown rim on the leeward of the drop impact site. The ligaments grow, coalesce, and fragment into secondary droplets. It is found that both the drag force and surface tension play important roles in the evolution process of the ligaments. The nondimensional K number (K = WeOh−0.4, where We is the Webber number and Oh is the Ohnesorge number) is used to describe the splashing-deposition limit of drop impact. The threshold value of this K number changes with the wind velocity and/or drop impact angle.

scholarly journals Vortex-ring-induced large bubble entrainment during drop impact

2016 ◽  
Vol 93 (3) ◽  
Author(s):  
Marie-Jean Thoraval ◽  
Yangfan Li ◽  
Sigurdur T. Thoroddsen
Keyword(s):  
Vortex Ring ◽  
Drop Impact ◽  
Large Bubble ◽  
Bubble Entrainment

Acoustics and hydrodynamics of a drop impact on a water surface

2017 ◽  
Vol 63 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Yu. D. Chashechkin ◽  
V. E. Prokhorov
Keyword(s):  
Water Surface ◽  
Drop Impact

Crown behavior and bubble entrainment during a drop impact on a liquid film

2013 ◽  
Vol 28 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Gangtao Liang ◽  
Yali Guo ◽  
Shengqiang Shen ◽  
Yong Yang
Keyword(s):  
Liquid Film ◽  
Drop Impact ◽  
Bubble Entrainment
Sign in / Sign up

Export Citation Format

Share Document