Unsteady shock wave diagnostics with high-speed imaging

Stone breakage in shock wave lithotripsy is improved by slowing the rate of shock wave (SW) delivery. Previous studies have shown that increased cavitation at fast pulse repetition frequency (PRF) reduces the tensile phase of the SW, while the leading positive wave is virtually unaffected. Since the tensile component of the SW drives cavitation, and since cavitation at the stone contributes to breakage, it seems likely that increased cavitation along the path to the stone affects cavitation at the stone. Here we present preliminary data suggesting that PRF influences bubble dynamics at the stone. High-speed imaging showed that as PRF increased, bubble density of cavitation clouds increased, and the size of individual bubbles decreased. A new method to measure stresses generated by cavitation was used to show that locally induced stresses from bubble collapse can be greater than the incident SW, and were higher at 0.5Hz than at 2Hz PRF.

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Observation of Shock Wave Phenomena by Using a High Speed Imaging

Journal of the Visualization Society of Japan ◽

10.3154/jvs.23.89 ◽

2003 ◽

Vol 23 (89) ◽

pp. 89-94_1

Author(s):

Kazuyoshi TAKAYAMA

Keyword(s):

Shock Wave ◽

High Speed ◽

High Speed Imaging ◽

Wave Phenomena

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Cavitating flow around a tandem of 2D hydrofoils: high-speed imaging and PIV measurements

Proceeding of THMT-18. Turbulence Heat and Mass Transfer 9 Proceedings of the Ninth International Symposium On Turbulence Heat and Mass Transfer ◽

10.1615/thmt-18.400 ◽

2018 ◽

Author(s):

Konstantin S. Pervunin ◽

Mikhail V. Timoshevskiy ◽

Dmitriy M. Markovich

Keyword(s):

High Speed ◽

Cavitating Flow ◽

High Speed Imaging ◽

Piv Measurements

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Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

Tire Science and Technology ◽

10.2346/tire.18.470101 ◽

2019 ◽

Vol 47 (3) ◽

pp. 196-210

Author(s):

Meghashyam Panyam ◽

Beshah Ayalew ◽

Timothy Rhyne ◽

Steve Cron ◽

John Adcox

Keyword(s):

High Speed ◽

Image Correlation ◽

Dynamic Mode Decomposition ◽

Dynamic Mode ◽

High Speed Imaging ◽

Correlation Algorithm ◽

Mode Decomposition ◽

Series Of Experiments ◽

Plane Deformations ◽

Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

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