Numerical Analysis of Water and Air in Venturi Tube to Produce Micro-Bubbles

Document Type : Regular Paper


1 Ph.D. Student of Hydraulic Structures, Department of Civil Engineering, Shahroud University of Technology, Shahrood, Iran Faculty Member of Islamic Azad University, Sarab Branch

2 Shahrood University of Technology

3 Professor, Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran


Two-phase flow regimes are affected by conduit position, alignment, geometry, flow direction, physical characteristics, and flow rate of each phase as well as the heat flux toward the boundaries. Due to the importance of two-phase flow, numerous regimes have been identified. The first step in studying micro-bubble formation inside a venturi tube is to recognize the type of flow regimes. In this study, which is devoted to the study of micro-bubble formation, a numerical investigation by OpenFOAM software and a VOF model was conducted. Results suggest that flow regime inside the venturi tube is roughly similar to flow regimes inside the horizontal tubes. For having bubble flow and consequently forming micro-bubble, flow rate of gas phase should be very smaller than liquid phase flow rate while the air inlet diameter should be chosen much smaller than water input diameter. Numerical simulations indicate that the best results are achieved for the water velocity of about 1-2m/s.


[1] Martin, CS.,’ (1976),Entrapped air in pipelines’, Proceeding of the second international conference on pressure purges, London, September 22-24, , BHRA Fluid Enginnering,Cranfiled, Bedford,England.
[2] Hewitt,G., and Taylor,N.S., (1970),Annular two-phase flow, Pergamon Press, Oxford.
[3] Zimmerman W. B. et al., Evaporation dynamics of Micro-bubbles, Chemical Engineering Science, Vol. 101, p. 865, 2013.
[4] Prevenslik T.: “Stability of nanobubbles by quantum mechanics”, Proc. of Conf. ‘Topical Problems of Fluid Mechnics’,p. 113, Prague 2014.
[5] katebi, A., khoshroo, M., shirzadi javid, A. (2017). 'The evaluation of concrete properties containing zeolite and micro-nano bubble water in the chloride curing condition', Amirkabir Journal of Civil Engineering, doi: 10.22060/ceej.2017.13603.5446.
[6] Soltani H., (2017), The effect of Nano bubbles on cellular lightweight concrete, MSc. Thesis, Shahrood university of technology, Shahrood, Iran.
[7] Madavan N.K. et al., Reduction of turbulent skin friction by Micro-bubbles, Physics of Fluids, Vol.27, p.356, 1984.
[8] Wataneabe K., et al.: Washing effect of Micro-bubbles, Paper OS1-01-1, Proc. of FLUCOME 2013, 12th Intern. Conf., Nara, Japan, November 2013.
[9] Kanagawa T.: Focused ultrasound propagation in water containing many therapeutical Micro-bubbles, Paper OS6-04-4, Proc. of FLUCOME 2013, 12th Intern. Conf., Nara, Japan, November 2013.
[10] Zimmerman W.B., Tesař V.: Bubble generation for aeration and other purposes, British Patent GB20060021561, Filed Oct. 2006.
[11 Zimmerman W. B. et al., Micro-bubble generation, Recent Patents in Engineering, Vol. 2: p.1, 2008.
[12] Raghu S.: Fluidic oscillators for flow control, Experiments in Fluids, Vol. 54, p. 1455, 2013.
[13] Gregory J. W., Tomac M. N.: A review of fluidic oscillator development and application for flow control, 43rd Fluid Dynamics Conf., Code 99250, 201.
[14] Tesař V.: Configurations of fluidic actuators for generating hybrid-synthetic jet Sensors and Actuators A: Physical, Vol. 138, p. 394, 2007.
[15] Tesař V., Zhong S., Fayaz R.: New fluidic oscillator concept for flow separation control, AIAA Journal, Vol. 51, p. 397, 2013.
[16] Tesař V., Hung C.-H., Zimmerman W. B. J.: No-moving-part hybrid-synthetic jet actuator, Sensors and Actuators, A: Physical, Vol. 125, p. 159, 2006.
[17] Kline,S. J., J. P. (1986). Diffusers - flow phenomena and design. In Advanced Topics in Turbomachinery Technology. Principal Lecture Series, No. 2. (D. Japikse, ed.) pp. 6-1 to 6-44, Concepts, ETI, 1986
[18] Mattew,P. and Peramaki,P.E., and Mark,D., And Nelson,P.E.,(2000), ‘The significance of two-phase flow regimes in designing multi-phase extractin systems, LBG Article,
[19] Baker, O.,(1954) ‘Simultaneous flow of oil and gas’, Oil Gas J., 53, 185–195.
[20] Baker,O., (1975), ‘Gas=liquid flow in pipeline, II.Design manual’, AGA-API project NX-28,.
[21] Mandhane J.M., Gregory G.A., Aziz K., (1974), ‘A flow pattern map for gas–liquid flow in horizontal pipes’, Int. J. Multiphase Flow, vol. 1, pp 537–553.
[22] Sandra C.K. De Schepper, Heynderickx G.J., Marin G.B., (2008), ‘CFD modeling of all gas–liquid and vapor–liquid flow regimes predicted by the Baker chart’, Chemical Engineering journal, vol. 138, pp 349–357.
[23] Krishnan R. N. , Vivek S. , Chatterjee D. , Das S. K.,( 2010), ‘Performance of numerical schemes in the simulation of two-phase free flows and wall bounded mini channel flows’, Chemical Engineering        Science journal, vol. 65 , pp 5117–5136.
[24] Ansari M.R., )1989(, ‘Slug mechanism in horizontal duct and simulation based on one-dimensional         two-fluid dynamics’, Ph.D. Thesis,Tsukuba University, Japan.
[25] Ansari M.R., Daramizadeh A., )2012(, ‘Slug type hydrodynamic instability analysis using a five        equations hyperbolic two-pressure, two-fluid model’, Ocean Engineering journal, vol. 52 , pp 1–12.
[26] Levy,S., (1999), ‘Two-phase flow in complex systems’, John Wiley & Sons, Inc., New York,.
[27] J. X. Zhang, Analysis on the effect of venturi tube structural parameters on fluid flow, AIP ADVANCES 7, 065315 (2017).
[28] H.Nilsson, H.jasak. source forge. OpenFOAM extension.[online], http//
[29] David C. Wilcox Turbulence modeling for CFD, third edition, DCW industries, Inc. 2006.
[30] C. W. HIRT AND B. D. NICHOLS, Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries, JOURNAL OF COMPUTATIONAL PHYSICS 39, 201-225 (1981)
[31] M.Ghannadi, S.F. Saghravani, H.niazmand, Dimensional analysis in the Study of Micro-Bubble Production Inside Venturi Tube, Trans. Phenom. Nano Micro Scales, 7(1), Winter and Spring 2019, DOI: 10.22111/tpnms.2018.23378.1139.