High-speed ultrasound imaging of laser-induced cavitation bubbles

2021 ◽  
Vol 119 (11) ◽  
pp. 114101
Author(s):  
S. Izak Ghasemian ◽  
F. Reuter ◽  
C. D. Ohl
Keyword(s):  
Ultrasound Imaging ◽  
High Speed ◽  
Cavitation Bubbles

scholarly journals A Photographic Study of Spark-Induced Cavitation Bubble Collapse

1972 ◽  
Vol 94 (4) ◽  
pp. 825-832 ◽  
Author(s):  
C. L. Kling ◽  
F. G. Hammitt
Keyword(s):  
Cavitation Bubble ◽  
High Speed ◽  
Bubble Collapse ◽  
Solid Boundary ◽  
High Speed Photography ◽  
Minimum Volume ◽  
Cavitation Bubbles ◽  
Flowing System

The collapse of spark-induced cavitation bubbles in a flowing system was studied by means of high speed photography. The migration of cavitation bubbles toward a nearby solid boundary during collapse and rebound was observed. Near its minimum volume the bubble typically formed a high speed microjet, which struck the nearby surface causing individual damage craters on soft aluminum.

Experimental Investigation on Cavitation Performance of Torque Converter Using Transparent Model

2019 ◽  
Author(s):  
Yusuke Katayama ◽  
Yuki Hosoi ◽  
Yuta Fukuda ◽  
Satoshi Watanabe ◽  
Shin-ichi Tsuda ◽  
...  
Keyword(s):  
High Speed ◽  
Turbine Blades ◽  
Suction Side ◽  
Torque Converter ◽  
Working Fluid ◽  
Speed Ratio ◽  
Cavitation Phenomenon ◽  
Cavitation Bubbles ◽  
Charge Pressure ◽  
Dissolved Air

Abstract In this study, we experimentally investigated the influence of the amount of dissolved air in working fluid and the rotation speed ratio of turbine to pump elements on cavitation phenomenon in automotive torque converter. In order to directly observe the cavitation phenomenon, transparent model was used. The applied charge pressure was varied to change the significance of cavitation. The pump and turbine torques were simultaneously measured to clarify the relation between torque performance and cavitation phenomenon. As a result, the cavitation region was found to depend on the speed ratio; cavitation occurred on the suction side of turbine blades at low speed ratios while in the pump region at high speed ratios. The effect of the amount of dissolved air was significant, which enhanced the growth of cavitation bubbles through the deposition of dissolved air. In such cases, with the further decrease of charge pressure, a large number of gaseous cavitation bubbles appeared in the whole flow passage. The torque performance was deteriorated at this stage.

scholarly journals Mitigating cavitation erosion using biomimetic gas-entrapping microtextured surfaces (GEMS)

2020 ◽  
Vol 6 (13) ◽  
pp. eaax6192 ◽  
Author(s):  
Silvestre Roberto Gonzalez-Avila ◽  
Dang Minh Nguyen ◽  
Sankara Arunachalam ◽  
Eddy M. Domingues ◽  
Himanshu Mishra ◽  
...  
Keyword(s):  
Solid Surface ◽  
Surface Hardening ◽  
High Speed ◽  
Cavitation Erosion ◽  
Flow Problem ◽  
Vapor Bubbles ◽  
Cavitation Damage ◽  
Cavitation Bubbles ◽  
Microtextured Surfaces ◽  
High Speed Flows

Cavitation refers to the formation and collapse of vapor bubbles near solid boundaries in high-speed flows, such as ship propellers and pumps. During this process, cavitation bubbles focus fluid energy on the solid surface by forming high-speed jets, leading to damage and downtime of machinery. In response, numerous surface treatments to counteract this effect have been explored, including perfluorinated coatings and surface hardening, but they all succumb to cavitation erosion eventually. Here, we report on biomimetic gas-entrapping microtextured surfaces (GEMS) that robustly entrap air when immersed in water regardless of the wetting nature of the substrate. Crucially, the entrapment of air inside the cavities repels cavitation bubbles away from the surface, thereby preventing cavitation damage. We provide mechanistic insights by treating the system as a potential flow problem of a multi-bubble system. Our findings present a possible avenue for mitigating cavitation erosion through the application of inexpensive and environmentally friendly materials.

scholarly journals Visualization of the Cavitation Bubbles on the Mechanical Heart Valves using High-speed Cameras

2002 ◽  
Vol 22 (1Supplement) ◽  
pp. 293-294
Author(s):  
Koki TAKIURA ◽  
Tsuneo CHINZEI ◽  
Yusuke ABE ◽  
Takashi ISOYAMA ◽  
Itsuro SAITO ◽  
...  
Keyword(s):  
High Speed ◽  
Heart Valves ◽  
Mechanical Heart Valves ◽  
Cavitation Bubbles

Study of Cavitation Bubbles Evolution for High-Speed Water-Lubricated Spiral Groove Thrust Bearings

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiaohui Lin ◽  
Ruiqi Wang ◽  
Shaowen Zhang ◽  
Chibin Zhang ◽  
Shuyun Jiang
Keyword(s):  
Theoretical Model ◽  
High Speed ◽  
Groove Depth ◽  
Skewed Distribution ◽  
Outer Diameter ◽  
Spiral Groove ◽  
High Rotational Speed ◽  
Cavitation Bubbles ◽  
Bubble Evolution ◽  
Bubble Number

The purpose of this study is to investigate the evolution of cavitation bubbles for the high-speed water-lubricated spiral groove thrust bearing. A theoretical model of cavitation bubble evolution considering multiple effects (interface, breakage, and coalescence of bubbles) was established for the bearing. A high-speed experimental setup was developed to measure the distribution of bubbles. The theoretical model is verified by the experimental data. The results show that the Boltzmann-type bubble transport equation can be used to describe the bubble evolution of the bearing under the breakup and coalescence at high-speed conditions; the volume of the bubble group presents a skewed distribution in equilibrium; the number of small-sized bubbles is greater than that of large-sized bubbles at high rotational speed; the bubbles are mainly distributed at the inlets and outlets of spiral grooves; the bubble number density increases with the groove depth and spiral angle; more bubbles are generated near the outer diameter of the bearing. The study provides a theoretical and experimental basis for the bubble evolution of the water-lubricated spiral groove bearing under high speeds.

High-speed visualization of acoustically excited cavitation bubbles in a cluster near a rigid boundary

2015 ◽  
Vol 20 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Haresh Anant Vaidya ◽  
Özgür Ertunç ◽  
Thomas Lichtenegger ◽  
Johannes Hachmann ◽  
Antonio Delgado ◽  
...  
Keyword(s):  
High Speed ◽  
Rigid Boundary ◽  
Cavitation Bubbles

Simultaneous observation of cavitation bubbles generated in biological tissue by high-speed optical and acoustic imaging methods

2017 ◽  
Vol 56 (7S1) ◽  
pp. 07JF27
Author(s):  
Kai Suzuki ◽  
Ryosuke Iwasaki ◽  
Ryo Takagi ◽  
Shin Yoshizawa ◽  
Shin-ichiro Umemura
Keyword(s):  
Biological Tissue ◽  
High Speed ◽  
Acoustic Imaging ◽  
Simultaneous Observation ◽  
Imaging Methods ◽  
Cavitation Bubbles
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