Observations of the Dynamics and Acoustics of Travelling Bubble Cavitation
- Creators
- Ceccio, Steven Louis
Abstract
Individual travelling cavitation bubbles generated on two axisymmetric headforms were detected using a surface electrode probe. The growth and collapse of the bubbles, almost all of which were quasi-spherical caps moving close to the headform surface, were studied photographically. Although the growth patterns for the two headforms were similar, the collapse mechanisms were quite different. These differences were related to the pressure fields and viscous flow patterns associated with each headform. Measurements of the acoustic impulse generated by the bubble collapse were analyzed and found to correlate with the maximum volume of the bubble for each headform. Numerical solutions of the Rayleigh-Plesset equation were generated for the same flows and compared with the experimental data. The experiments revealed that for smaller bubbles the impulse-volume relationship is determinate, but for larger bubbles the impulse becomes more uncertain. The theoretical impulse was at least a factor of two greater than the measured impulse, and the impulse-volume relationship was related to the details of the collapse mechanism. Acoustic emission of individual cavitation events was spectrally analyzed and the results were compared with relevant theoretical and empirical predictions. Finally, the cavitation nuclei flux was measured and compared to the cavitation event rate and the bubble maximum size distribution through the use of a simple model. The nuclei number distribution was found to vary substantially with tunnel operating conditions, and changes in the nuclei number distribution significantly influenced the cavitation event rate and bubble maximum size distribution. The model estimated the cavitation event rate but failed to predict the bubble maximum size distribution. With the above theoretical and experimental results, the cavitation rate and resulting noise production may be estimated from a knowledge of the non-cavitating flow and the free stream nuclei number distribution.
Additional Information
©1990 Steven Louis Ceccio. Report No. ENG 249.11 on Contract N00014-85-K-0597. I would like to express my deepest gratitude to my advisor, Professor Christopher Brennen. His professional and personal guidance made the completion of this work possible. Furthermore, I would like to thank Professor Allan Acosta, whose advice and considerations proved invaluable. The continued interest Professors Rolf Sabersky and Thomas Caughey have expressed in this work is greatly appreciated. This thesis relied heavily upon the professional staff of Caltech, and I thank all those people that contributed. I would especially like to thank John Lee for his assistance in the electrical design, Marty Gould for his expert machining and patient advice, and Cecilia Lin for her preparation of the figures. I would also like to express my gratitude to Jackie Beard and Dana Young for their support and encouragement. I gratefully acknowledge the help of my fellow graduate students, especially Ron Franz, Douglas Hart, Sanjay Kumar, and Adiel Guinzburg. I would also like to acknowledge the numerous undergraduates who have assisted in this work with special thanks to Imran Kizilbash and Dong-Su Kim. Funding for this work was provided by the Office of Naval Research under contract number N-00014-85-K-0397, and the Francis J. Cole Foundation and the ARCS Foundation also provivided financial assistance. This support was essential to the completion of this work. Last, but certainly not least, I thank my family for their unfailing encouragement and understanding. This work would not have been possible without the loving support of my parents, and I therefore dedicate it to them.Attached Files
Submitted - Report_No._ENG_249.11.pdf
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Additional details
- Eprint ID
- 45650
- Resolver ID
- CaltechAUTHORS:20140509-141304905
- N-00014-85-K-0397
- Office of Naval Research
- Francis J. Cole Foundation
- ARCS Foundation
- Created
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2014-05-12Created from EPrint's datestamp field
- Updated
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2019-10-03Created from EPrint's last_modified field