Experimental Investigation of Cavitation Phenomena Around the Body with the Conic Nose and Cylindrical Afterbody

Authors

Department of Mechanical Engineering, semnan University, semnan, Iran.

Abstract

In this paper, the inception, growth and development of cavitation are investigated around the combined body experimentally. The diameter of afterbody and the length of model are 25 and 210 mm respectively. The angles of conic nose are 〖30〗^° and 〖45〗^°. Models were tested in a high speed closed circuit cavitation tunnel. A peripheral groove is established on the afterbody and then one conic nose, experiments are repeated in these cases. A comparison was done between all cases. For 〖30〗^° model with groove on afrebody and without groove, cavitation is initiated at a small distance behind the body. If the groove is established on the nose then cavitation is initiated into it. In 〖45〗^° model, cavitation is initiated on the interface of the nose and afterbody. Into the groove and behind of afterbody, cavitation will be initiated at the center of vortex resulted by separation. By developing the length of cavitation on the afterbody, regular longitudinal oscillations will be occurred. Behind the model, inside the wake of body, cavitation initiates at the center of annular vortex. After developing the length of cavitation area ,bubble shedding occurs at the end of cavitation region. During the fluctuating of cavitation area, bubble shedding occurs randomly. In these cases, intense noise is heard.

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References

[1] Reichardt H (1954) The physical laws governing the cavitation bubbles produced behind solids of revolution in a fluid flow. The Kaiser Wilhelm Institute for Hydrodynamic Research, Gottingen, Rep. UM, Vol. 6628.
[2] Savchenko YN, Vlasenko YD, Semenenko V(1999) Experimental studies of high-speed cavitated flows. Int J Fluid Mech Res 26(3).
[3] Vlasenko YD (2003) Experimental investigation of supercavitation flow regimes at subsonic and transonic speeds. In Fifth International Symposium on Cavitation, Osaka, Japan 1-8.
[4] Hrubes J (2001) High-speed imaging of supercavitating underwater projectiles. Exp Fluids 30(1): 57-64.
[5] Wosnik M, Schauer TJ, Arndt RE (2003) Experimental study of a ventilated supercavitating vehicle. in Proceeding of 5Th International Symposium on Cavitation, Osaka, Japan 1-4.
[6] Chao H, Yang H, Zhao C, Huang WH (2006) Unsteady supercavitating flow past cones. Project Supported by the National Nature Science Foundation of China (Grant No: 10572045) and Distinguished Young Scholar Science Foundation of Heilongjiang Province of China (Grant No: JC-9), J Hydrodyn 18(3): 262-272.
[7] Zhang XW, Wei YJ, Zhang JZ, Cong W, Yu KP (2007) Experimental research on the shape characters of natural and ventilated supercavitation. J Hydrodyn 19(5): 564-571.
[8] Ahn BK, Lee CS, Kim HT (2010) Experimental and numerical studies on super-cavitating flow of axisymmetric cavitators. Int J Nav Arch Ocean 2(1): 39-44
[9] Arndt RE (1981) Cavitation in fluid machinery and hydraulic structures. Annu Rev Fluid Mech 13(1): 273-326.
[10] Franc JP, Michel JM (2006) Fundamentals of cavitation. Springer Science & Business Media.
[11] Ling SC, Gowing S, Shen YT (1982) The Role of microbubbles on cavitation inception on head forms. David Taylor Research Center Report.
[12] Ceccio SL, Brennen CE (1991) Observations of the dynamics and acoustics of travelling bubble cavitation. J Fluid Mech 233: 633-660.
[13] Arakeri V, Acosta A (1973) Viscous effects in the inception of cavitation on axisymmetric bodies. J Fluid Eng-T ASME 95: 519-527.
[14] Hu CL, Wang GY, Huang B, Yu Z (2015) The inception cavitating flows over an axisymmetric body with a blunt head-form. J Hydrodyn 27(3): 359-366.
[15] شمس­الدینی ر، قدسی ر (1397) تحیل عددی دو بعدی و سه­بعدی پدیده سوپرکاویتاسیون در حالت تزریق و بدون تزریق بخار و هوا بر روی سطح متحرک زیرسطحی. مجله علمی پژوهشی مکانیک سازه‌ها و شاره‌ها 240-229 :(1)8.
[16] جعفری گاوزن ا، جدیدی ام (1397) بررسی تجربی رفتار حدی پدیده کاویتاسیون حول استوانه با اندازه های مختلف در تونل کاویتاسیون سرعت بالا. مجله علمی پژوهشی مکانیک سازه‌ها و شاره‌ها 156-147 :(1)8.
[17] فروزانی ح، سرانجام ب، کمالی ر، ربیعی ع (1396)       شبیه­سازی عددی و بررسی تجربی حرکت یک جسم پرسرعت زیر سطحی. مجله علمی پژوهشی مکانیک سازه‌ها و شاره‌ها 230-217 :(1)7. 
Journal of Solid and Fluid Mechanics
Volume 9, Issue 2
June 2019
Pages 249-259

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