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Ventilated supercavitation around a moving body in a still fluid: observation and drag measurement

  • Jaeho Chung (a1) and Yeunwoo Cho (a1)


This experimental study examines ventilated supercavity formation in a free-surface bounded environment where a body is in motion and the fluid is at rest. For a given torpedo-shaped body and water depth ( $H$ ), depending on the cavitator diameter ( $d_{c}$ ) and the submergence depth ( $h_{s}$ ), four different cases are investigated according to the blockage ratio ( $B=d_{c}/d_{h}$ , where $d_{h}$ is the hydraulic diameter) and the dimensionless submergence depth ( $h^{\ast }=h_{s}/H$ ). Cases 1–4 are, respectively, no cavitator in fully submerged ( $B=0$ , $h^{\ast }=0.5$ ), small blockage in fully submerged ( $B=1.5\,\%$ , $h^{\ast }=0.5$ ), small blockage in shallowly submerged ( $B=1.5\,\%$ , $h^{\ast }=0.17$ ) and large blockage in fully submerged ( $B=3\,\%$ , $h^{\ast }=0.5$ ) cases. In case 1, no supercavitation is observed and only a bubbly flow (B) and a foamy cavity (FC) are observed. In non-zero blockage cases 2–4, various non-bubbly and non-foamy steady states are observed according to the cavitator-diameter-based Froude number ( $Fr$ ), air-entrainment coefficient ( $C_{q}$ ) and the cavitation number ( $\unicode[STIX]{x1D70E}_{c}$ ). The ranges of $Fr$ , $C_{q}$ and $\unicode[STIX]{x1D70E}_{c}$ are $Fr=2.6{-}18.2$ , $C_{q}=0{-}6$ , $\unicode[STIX]{x1D70E}_{c}=0{-}1$ for cases 2 and 3, and $Fr=1.8{-}12.9$ , $C_{q}=0{-}1.5$ , $\unicode[STIX]{x1D70E}_{c}=0{-}1$ for case 4. In cases 2 and 3, a twin-vortex supercavity (TV), a reentrant-jet supercavity (RJ), a half-supercavity with foamy cavity downstream (HSF), B and FC are observed. Supercavities in case 3 are not top–bottom symmetric. In case 4, a half-supercavity with a ring-type vortex shedding downstream (HSV), double-layer supercavities (RJ inside and TV outside (RJTV), TV inside and TV outside (TVTV), RJ inside and RJ outside (RJRJ)), B, FC and TV are observed. The cavitation numbers ( $\unicode[STIX]{x1D70E}_{c}$ ) are approximately 0.9 for the B, FC and HSF, 0.25 for the HSV, and 0.1 for the TV, RJ, RJTV, TVTV and RJRJ supercavities. In cases 2–4, for a given $Fr$ , there exists a minimum cavitation number in the formation of a supercavity while the minimum cavitation number decreases as the $Fr$ increases. In cases 2 and 3, it is observed that a high $Fr$ favours an RJ and a low $Fr$ favours a TV. For the RJ supercavities in cases 2 and 3, the cavity width is always larger than the cavity height. In addition, the cavity length, height and width all increase (decrease) as the $\unicode[STIX]{x1D70E}_{c}$ decreases (increases). The cavity length in case 3 is smaller than that in case 2. In both cases 2 and 3, the cavity length depends little on the $Fr$ . In case 2, the cavity height and width increase as the $Fr$ increases. In case 3, the cavity height and width show a weak dependence on the $Fr$ . Compared to case 2, for the same $Fr$ , $C_{q}$ and $\unicode[STIX]{x1D70E}_{c}$ , case 4 admits a double-layer supercavity instead of a single-layer supercavity. Connected with this behavioural observation, the body-frontal-area-based drag coefficient for a moving torpedo-shaped body with a supercavity is measured to be approximately 0.11 while that for a cavitator-free moving body without a supercavity is approximately 0.4.


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Cameron, P. J. K., Rogers, P. H., Doane, J. W. & Gifford, D. H. 2011 An experiment for the study of free-flying supercavitating projectiles. Trans. ASME J. Fluids Engng 133 (2), 021305.
Campbell, I. J. & Hilborne, D. V. 1958 Air entrainment behind artificially inflated cavities. In Proc. of 2nd Symp. on Naval Hydrodynamics, Washington, DC. Office of Naval Research.
Ceccio, S. L. 2010 Friction drag reduction of external flows with bubble and gas injection. Annu. Rev. Fluid Mech. 42, 183203.
Cox, R. N. & Clayden, W. A. 1956 Air entrainment at the rear of a steady cavity. In Proc. of Symp. on Cavitation in Hydrodynamics, London. National Physical Laboratory.
Epshtein, L. A. 1973 Characteristics of ventilated cavities and some scale effects, unsteady water flow with high velocities. In Proc. of IUTAM Symp. on Non-steady Flow of Water at High Speeds, Leningrad. Nauka Publishing House.
Franc, J. P. & Michel, J. M. 2004 Fundamentals of Cavitation. Kluwer Academic Publishers.
Gadd, G. E. & Grant, S. 1965 Some experiments on cavities behind disks. J. Fluid Mech. 23 (4), 645656.
Garabedian, P. R. 1955 Calculation of axially symmetric cavities and jets. Pac. J. Maths. 6 (4), 611684.
Goldstein, S. 1938 Modern Developments in Fluid Dynamics. Oxford University Press.
Haaland, S. E. 1983 Simple and explicit formulas for the friction factor in turbulent pipe flow. Trans. ASME J. Fluids Engng 105 (1), 8990.
Haipeng, W., Song, F., Qin, W., Biao, H. & Guoyu, W. 2014 Experimental and numerical research on cavitating flows around axisymmetric bodies. J. Mech. Sci. 28 (11), 45274537.
Hrubes, J. D. 2001 High-speed imaging of supercavitating underwater projectiles. Exp. Fluids 30 (1), 5764.
Kapankin, Y. N. & Gusev, A. V. 1984 Experimental research of joint influence of fluid and lift power of cavitator on character of flow in cavity rear part and gas departure from it. In Proc. CAHI, vol. 2244, pp. 1928.
Karlikov, V. P., Reznichenko, N. T., Khomyakov, A. N. & Sholomovich, G. I. 1987 A possible mechanism for the emergence of auto-oscillations in developed artificial cavitation flows and immersed gas jets. Fluid Dyn. 22 (3), 392398.
Karn, A., Arndt, R. E. A. & Hong, J. 2016 An experimental investigation into supercavity closure mechanisms. J. Fluid Mech. 789, 259284.
Kawakami, E.2010 Investigation of the behavior of ventilated supercavities. MS thesis, University of Minnesota, Twin Cities.
Kawakami, E. & Arndt, R. E. A. 2011 Investigation of the behavior of ventilated supercavities. Trans. ASME J. Fluids Engng 133 (9), 091305.
Kuklinski, R., Henoch, C. & Castano, J. 2001 Experimental study of ventilated cavities on dynamic test model. In CAV2001: Fourth Intl Symp. on Cavitation, pp. 18. Naval Undersea Warfare Center.
Logvinovich, G. V. 1972 Hydrodynamics of Free-boundary Flows (Translated form Russian). IPST Press.
Nouri, N. M., Madoliat, R., Jahangardy, Y. & Abdolahi, M. 2015 A study on the effects of fluctuations of the supercavity parameters. Exp. Therm. Fluid Sci. 60, 188200.
Panton, R. L. 2005 Incompressible Flow, 3rd edn. Wiley.
Reichardt, H.1946 The laws of cavitation bubbles at axially symmetrical bodies in a flow. Rep. and Trans. 35. Ministry of Aircraft Production, Great Britain.
Schaffar, M., Rey, C. & Boeglen, G. 2005 Behavior of supercavitating projectiles fired horizontally in water tank: theory and Experiments-CFD Computations with the OTi-Hull hydrocode. In Proc. Thirty fifth AIAA Fluid Dynamic Conf. and Exhi., Toronto, pp. 18.
Schauer, T. J.2003 An experimental study of a ventilated supercavitating vehicle. MS thesis, University of Minnesota, Twin Cities.
Self, M. W. & Ripken, J. F.1955 Steady-state cavity studies in a free-jet water tunnel. Rep. 47. St. Anthony Fall Hydraulic Laboratory, University of Minnesota, Twin Cities.
Semenenko, V. N. 2001a Artificial Supercavitation: Physics and Calculation. Institute of Hydromechanics, National Academy of Sciences of Ukraine.
Semenenko, V. N. 2001b Dynamic Processes of Supercavitation and Computer Simulation. Institute of Hydromechanics, National Academy of Sciences of Ukraine.
Silberman, E. & Song, C. S. 1961 Instability of ventilated cavities. J. Ship Res. 5 (1), 1333.
Skidmore, G.2013 The pulsation of ventilated supercavities. Master of Science thesis, Department of Aerospace Engineering, Pennsylvania State University, University Park.
Song, C. S.1961 Pulsation of ventilated cavities. Rep. 32B. St. Anthony Fall Hydraulic Laboratory, University of Minnesota, Twin Cities.
Spurk, J. H. & König, B. 2002 On the gas loss from ventilated supercavities. Acta Mech. 155, 125135.
Sumer, B. M. & Fredsoe, J 2010 Hydrodynamics Around Cylindrical Structures. World Scientific.
Waid, R. L.1957 Cavity shapes for circular disks at angles of attack. Rep. E-73.4. Hydrodynamics Laboratory, California Institute of Technology, Pasadena.
White, F. M. 1999 Fluid Mechanics, 4th edn. McGraw-Hill.
Zhou, J., Yu, K., Min, J. & Yang, M. 2010 The comparative study of ventilated super cavity shape in water tunnel and infinite flow field. J. Hydrodyn. B 22 (5), 689696.
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Journal of Fluid Mechanics
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