Mechanism and Control of Cloud Cavitation

Journal of Fluids Engineering, Transactions of the ASME - Tập 119 Số 4 - Trang 788-794 - 1997
Yasutaka Kawanami1, Hiroharu Kato1, Hajime Yamaguchi1, Masaharu Tanimura1, Yu Tagaya1
1Department of Naval Architecture and Ocean Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113 Japan

Tóm tắt

Generation mechanism of cloud cavitation on a hydrofoil section was investigated in a sequence of experiments through observation of cloud cavitation by high-speed video and high-speed photo as well as pressure measurements by pressure pick-ups and a hydrophone. The mechanism was also investigated by controlling cloud cavitation with an obstacle fitted on the foil surface. From the results of these experiments, it was found that the collapse of a sheet cavity is triggered by a re-entrant jet rushing from the trailing edge to the leading edge of the sheet cavity, and consequently, the sheet cavity is shed in the vicinity of its leading edge and thrown downstream as a cluster of bubbles called cloud cavity. In other words, the re-entrant jet gives rise to cloud cavitation. Moreover, cloud cavitation could be controlled effectively by a small obstacle placed on the foil. It resulted in reduction of foil drag and cavitation noise.

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Tài liệu tham khảo

Avellan, F., Dupont, P. and Rhyming, I., 1988, “Generation Mechanism and Dynamics of Cavitation Vortices Downstream of a Fixed Leading Edge Cavity,” 17th Symposium on Naval Hydrodynamics, pp. 317–329.

Avellan, F. and Farhat, M., 1989, “Shock Pressure Generated by Cavitation Vortex Collapse,” ASME International Symposium on Cavitation and Erosion in Fluid Systems, FED-88, pp. 119–125.

de Lange, D. F., de Bruin, G. J. and van Wijngaarden, L., 1994, “On the Mechanism of Cloud Cavitation—Experiments and Modeling,” 2nd International Symposium on Cavitation (Cav, ’94), pp. 45–50.

Furness R. A. and HuttonS. P., 1975, “Experimental and Theoretical Studies of Two-Dimensional Fixed-Type Cavities,” ASME JOURNAL OF FLUIDS ENGINEERING, Vol. 97, No. 4, pp. 515–522.

Jakobsen J. K. , 1964, “On the Mechanism of Head Breakdown in Cavitating Inducers,” ASME Journal of Basic Engineering, Vol. 86, pp. 291–305.

Kubota A. , KatoH., YamaguchiH., and 1989, “Unsteady Structure Measurement of Cloud Cavitation on a Foil Section using Conditional Sampling Technique,” ASME JOURNAL OF FLUIDS ENGINEERING, Vol. 111, No. 2, pp. 204–210.

Kubota A. , KatoH., and YamaguchiH., 1992, “A New Modeling of Cavitating Flows: a Numerical Study of Unsteady Cavitation on a Hydrofoil Section,” Journal of Fluid Mechanics, Vol. 240, pp. 59–96.

Larrarte, F., Pauchet, A., Bousquet, Ph., and Fruman, D. H., (1995), “On the Morphology of Natural and Ventilated Cavities,” ASME Cavitation and Multiphase Flow, FED-210, pp. 31–38.

Le Q. , FrancJ. P. and MichelJ. M., 1993, “Partial Cavities: Grobal Behavior and Mean Pressure Distribution,” ASME JOURNAL OF FLUIDS ENGINEERING, Vol. 115, pp. 243–248.

Lush P. A. , and SkippS. R., 1986, “High Speed Cine Observations of Cavitating Flow in a Duct,” International Journal of Heat Fluid Flow, Vol. 7, No. 4, pp. 283–290.

Mo̸rch, K. A., 1981, “Cavity Cluster Dynamics and Cavitation Erosion,” ASME Cavitation and Polyphase Flow Forum, pp. 1–10.

Noordzij L. and Van WijngaardenL., 1974, “Relaxation Effects, Caused by Relative Motion, on Shock Waves in Gas-Bubble/Liquid Mixtures,” Journal of Fluid Mechanics, Vol. 66, pp. 115–143.

Shen, Y. T. and Peterson, F. B., 1978, “Unsteady Cavitation on an Oscillating Hydrofoil,” 12th Symposium on Naval Hydrodynamics, pp. 362–384.