بررسی تجربی رفتار هیدرودینامیکی و شکست جت مایع با و بدون حضور میدان الکتریکی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار/ دانشگاه شهید مدنی آذربایجان

2 دانشگاه شهید مدنی آذربایجان، تبریز ، ایران

3 دانشیار/دانشگاه تبریز

چکیده

در کار حاضر، رفتار هیدرودینامیکی جت سیال با و بدون اعمال میدان الکتریکی مطالعه شده و اثر شدت و جهت اعمال میدان الکتریکی بر ناپایداری و شکست جت به روش تجربی مورد بررسی قرار گرفته است. نتایج به‌دست آمده نشان می‌دهند که درجت‌های آزادی که فقط تحت تأثیر گرانش می‌باشند، مشخصات جت سیال وابسته به عدد رینولدز است؛ در این نوع جت‌ها، قطر متوسط جت و طول شکست آن با عدد رینولدز رابطه مستقیم دارد. اعمال میدان الکتریکی قطر متوسط جت در ناحیه پائین دست الکترودها را افزایش و طول شکست آ ن را کاهش می‌دهد و اثر میدان مستقیم در کاهش طول شکست بیشتر از میدان معکوس می‌باشد. با اعمال اختلاف پتانسیل 6 کیلوولت، می‌توان طول شکست بالایی جت را به میزان 27 درصد نسبت به حالت بدون میدان کوتاه‌تر کرد. انحراف معیار قطره‌های تولید شده در حالت بدون میدان و میدان الکتریکی مخالف حاصل از 2کیلوولت به ترتیب برابر با 3/ 1 و 1/ 1 میلی‌متر می‌باشد که حاکی از یکنواختی بیشتر قطرات در حضور میدان مخالف است. با توجه به ضرایب گردی ذرات مختلف تولید شده، می‌توان گفت که میدان الکتریکی باعث تولید قطرات با گردی بیشتر شده و فراوانی قطرات نامنظم را کاهش می‌دهد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Experimental Study of Hydrodynamic Behavior and Breakup of Liquid Jet with/ without the Electric Field

نویسندگان [English]

  • Reza Gharraei Khosroshahi 1
  • Mahdi Tavana 2
  • Sima Baheri Islami 3
1 Mechanical Engineering Department, Azarbaijan Shahid Madani University
2 Mechanical Engineering Department, Azarbaijan Shahid Madani University, Tabriz, Iran
3 Associate Professor/ University of Tabriz
چکیده [English]

In this study, the hydrodynamic behavior of fluid jet with/without application of electric field is studied and intensity and direction of the electrical field are investigated experimentally on instability and jet breakup. The study of the shape and size of produced droplets after the fluid jet breakup are another cases in this study. Results show that fluid jet characteristics depend on Reynolds number in jets which are only based on gravity. Jet mean diameter and its breakup length in this type of jets are directly related to Reynolds number. Studies show that jet mean diameter is increased and breakup length is decreased by applying electrical field. According to investigations, increasing of electrical field intensity leads to decreasing in jet breakup length and direct field has a significant effect in comparison with reverse one on it. Studies show that jet mean diameter and breakup length are decreased by applying electrical field. Increasing of electrical field intensity leads to decreasing in jet breakup length and direct field has a significant effect in comparison with reverse one on it. By applying a 6 kV electric field, the upper jet breakup length can be reduced by 27% in comparison with non-field state. The standard deviation of produced droplets in non-filed state and reverse electrical field with 2kV intensity is equal to 1.3 and 1.1, respectively which indicates a more uniform droplet in presence of reverse electric field. The investigation of produced droplets in term of roundness showed that electrical field leads to producing circular droplets and reducing the frequency of irregular droplets.

کلیدواژه‌ها [English]

  • Fluid Jet
  • Breakup length
  • Electrohydrodynamic
  • Dielectric

مراجع

[1] G. Bidone, Expériences sur la forme et sur  la direction des veines et des courans [sic] d'eau lancés par diverses ouvertures, Imprimerie royale, (1829).
[2] K. Amagai, M. Arai, Frequency analysis of disintegrating liquid column, International Journal of Fluid Mechanics Research, 24 (1997) 1-3.
[3] J. Eggers, E. Villermaux, Physics of liquid jets, Reports on progress in physics, 71(3) (2008) 036601.
[4] J. Blaisot, S. Adeline, Instabilities on a free falling jet under an internal flow breakup mode regime, International journal of multiphase flow, 29(4) (2003) 629-653.
[5] C. Cramer, P. Fischer, E.J. Windhab, Drop formation in a co-flowing ambient fluid, Chemical Engineering Science, 59(15) (2004) 3045-3058.
[6] B. Cheong, T. Howes, Capillary jet instability under the influence of gravity, Chemical engineering science, 59(11) (2004) 2145-2157.
[7] M. Hojjati, E. Esmaeilzadeh, B. Sadri, R. Gharraei, Electrohydrodynamic conduction pumps with cylindrical electrodes for pumping of dielectric liquid film in an open channel, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 392(1) (2011) 294-299.
[8] Y. Gan, Z. Luo, Y. Cheng, J. Xu, The electro-spraying characteristics of ethanol for application in a small-scale combustor under combined electric field, Applied Thermal Engineering, 87 (2015) 595-604.
[9] B. Khorshidi, M. Jalaal, E. Esmaeilzadeh, Electrohydrodynamic instability at the interface between two leaky dielectric fluid layers, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 380(1) (2011) 207-212.
[10] B.V. Hokmabad, S. Faraji, T.G. Dizajyekan, B. Sadri, E. Esmaeilzadeh, Electric field-assisted manipulation of liquid jet and emanated droplets, International Journal of Multiphase Flow, 65 (2014) 127-137.
[11] S. Faraji, M.F. Yardim, D.S. Can, A.S. Sarac, Characterization of polyacrylonitrile, poly (acrylonitrile- co-vinyl acetate), and poly (acrylonitrile-co-itaconic acid) based activated carbon nanofibers, Journal of Applied Polymer Science, 134(2) (2017) 44381.
[12] Y. Wu, J.A. MacKay, J. R. McDaniel, A. Chilkoti, R.L. Clark, Fabrication of elastin-like polypeptide nanoparticles for drug delivery by electrospraying, Biomacromolecules, 10(1) (2008) 19-24.
[13] B. Sadri, B.V. Hokmabad, E. Esmaeilzadeh, R. Gharraei, Experimental investigation of electrosprayed droplets behaviour of water and KCl aqueous solutions in silicone oil, Experimental Thermal and Fluid Science, 36 (2012) 249-255.
[14] P. Foroughi, Design and characterization of an electrohydrodynamic (EHD) micropump for cryogenic spot cooling applications, University of Maryland, College Park, 2008.
[15] S. Arumuganathar, S. Jayasinghe, N. Suter, Unique aerodynamically driven methodology for forming droplets, threads to scaffolds, Journal of applied polymer science, 104(6) (2007) 3844-3848.
[16] A. Bateni, S. Laughton, H. Tavana, S. Susnar, A. Amirfazli, A. Neumann, Effect of electric fields on contact angle and surface tension of drops, Journal of colloid and interface science, 283(1) (2005) 215-222.
[17] A. Atten, S. Oliveri, Charging of drops formed by circular jet breakup, Journal of electrostatics, 29(1) (1992) 73-91.
[18] F. Li, X.-Y. Yin, X.-Z. Yin, Axisymmetric and non- axisymmetric instability of an electrified viscous coaxial jet, Journal of Fluid Mechanics, 632 (2009) 199-225.
[19] L.-j. Yang, Y.-x. Liu, Q.-f. Fu, Linear stability analysis of an electrified viscoelastic liquid jet, Journal of Fluids Engineering, 134(7) (2012) 071303.
[20] A. Khoshnevis, M.F. Tabriz, M. Hemayatkhah, A.E. Kandjani, J.M. Milani, E. Esmaeilzadeh, M. Eslamian, M.R. Vaezi, Characteristics of the breakup and fragmentation of an electrohydrodynamic melt jet, Particuology, 10(3) (2012) 255-265.
[21] P. Tabatabaee-Hosseini, B. Sadri, E. Esmaeilzadeh, Experimental study on the impinging of two opposed inclined electrified laminar jets in the stagnant dielectric medium, Experimental Thermal and Fluid Science, 42 (2012) 230-239.
[22] M. Rahmanpour, R. Ebrahimi, Numerical simulation of electrohydrodynamic spray with stable Taylor cone–jet, Heat and Mass Transfer, 52(8) (2016) 1595-1603.
[23] M. Yu, K.H. Ahn, S.J. Lee, Interplay between electrical and rheological properties of viscoelastic inks, Applied Physics A, 122(4) (2016) 1-8.
[24] S. Faraji, B. Sadri, B.V. Hokmabad, N. Jadidoleslam, E. Esmaeilzadeh, Experimental study on the role of electrical conductivity in pulsating modes of electrospraying, Experimental Thermal and Fluid Science, 81 (2017) 327- 335.
[25] R. Gharraei, M. Hemayatkhah, S.B. Islami, E. Esmaeilzadeh, An experimental investigation on the developing wavy falling film in the presence of electrohydrodynamic conduction phenomenon, Experimental Thermal and Fluid Science, 60 (2015) 35-44.
[26] T. Karapantsios, S.t. Paras, A. Karabelas, Statistical characteristics of free falling films at high Reynolds numbers, International Journal of Multiphase Flow, 15(1) (1989) 1-21.
[27] R. Grant, S. Middleman, Newtonian jet stability, AIChE Journal, 2 (1966) 669-678.
نشریه مهندسی مکانیک امیرکبیر
دوره 51، شماره 6
بهمن و اسفند 1398
صفحه 1487-1498

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