شبیه‌سازی عددی هیدرودینامیک جریان‌ چند فازی گاز-جامد در بستر دوار: تأثیر ضریب ارتجاعی بر ضخامت لایه فعال

نوع مقاله : ترویجی

نویسندگان

1 کارشناسی ارشد مهندسی شیمی، آزمایشگاه تحقیقاتی دینامیک سیالات محاسباتی (CFD)، دانشکده مهندسی شیمی، دانشگاه علم و صنعت ایران

2 دانشیار، آزمایشگاه تحقیقاتی دینامیک سیالات محاسباتی (CFD)، دانشکده مهندسی شیمی، دانشگاه علم و صنعت ایران

چکیده

در مطالعه حاضر به شبیه‌سازی دوبعدی هیدرودینامیک بستر گاز - جامد دوار در رژیم غلتان به‌منظور استفاده در پیرولیز ضایعات پلیمری پرداخته شده است. مدل‌سازی با رویکرد اولرین - اولرین به همراه نظریه جنبشی جریان‌های دانه‌ای انجام شده است. نتایج حاصل از شبیه‌سازی با کار آزمایشگاهی انجام شده در بستر دوار توسط سانتوس و همکاران (2015) مقایسه شد که حاکی از انطباق خوب نتایج با کارهای آزمایشگاهی بوده است. در این پژوهش به بررسی تأثیر پارامتر ضریب ارتجاعی بر ضخامت لایه فعال پرداخته شده است. بدین منظور مقادیر مختلف ضریب ارتجاعی (0/85، 0/9، 0/92 و 0/95) انتخاب شده و تأثیر آن بر ضخامت لایه فعال در بستر دوار بررسی شده است. با افزایش ضریب ارتجاعی از 0/85 تا 0/95 میزان ضخامت لایه فعال افزایش یافته که با توجه به اینکه بخش اصلی اختلاط در بسترهای دوار صورت می‌گیرد، می‌توان تأثیر آن در بهبود اختلاط در بسترهای دوار را با در نتایج مشاهده کرد.

کلیدواژه‌ها

عنوان مقاله [English]

Numerical Simulation of Multi-Phase Flow Hydrodynamic in Rotating Drum: Effect of Restitution Coefficient on Active Layer Thickness

نویسندگان [English]

  • afshin taghizade 1
  • Seyed Hassan Hashemabadi 2
1 Msc. in Chemical Engineering, Computational Fluid Dynamics (CFD) Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran, Iran
2 Professor Associated of Computational Fluid Dynamics (CFD) Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran, Iran
چکیده [English]

A two-dimensional hydrodynamic simulation of two-phase flow in a rotating drum under rolling conditions was examined in this study. The Eulerian-Eulerian multi-phase approach was utilized in this study to model the gas-solid system in a rotating drum, combined with the kinetic theory of granular flow. The results of these simulation was verified with experimental data was reported with Santos et al. (2015) which indicates that the results are consistent with experimental work. In this study impact of restitution coefficient on active layer thickness was investigated. For this purpose the restitution value set to different values (0.85, 0.9, 0.92, and 0.95) and their effect on the thickness of active layer on the rotating drum was examined. The thickness of the active layer was increased by raising the coefficient of restitution from 0.85 to 0.95, which, given that the majority of mixing occurs in rotating beds, can demonstrate an improvement in the degree of mixing in rotating beds with the results.

کلیدواژه‌ها [English]

  • Rotating Bed
  • Hydrodynamic
  • Numerical Simulation
  • Restitution Coefficient
  • Active Layer

مراجع

[1] Henein, H., J.K. Brimacombe, and A.P. Watkinson, Experimental study of transverse bed motion in rotary kilns. Metallurgical Transactions B, 1983. 14 (2): pp. 191-205.
[2] Chou, S.H. and S.S. Hsiau, Dynamic properties of immersed granular matter in different flow regimes in a rotating drum. Powder Technology, 2012. 226: pp. 99-106.
[3] Huang, A.N. and H.P. Kuo, A study on the transition between neighbouring drum segregated bands and its application to functionally graded material production. Powder Technology, 2011. 212 (2): pp. 348-353.
[4] Finnie, G.J., et al., Longitudinal and transverse mixing in rotary kilns: A discrete element method approach. Chemical Engineering Science, 2005. 60 (15): pp. 4083-4091.
[5] Kwapinska, M., G. Saage, and E. Tsotsas, Mixing of particles in rotary drums: A comparison of discrete element simulations with experimental results and penetration models for thermal processes. Powder Technology, 2006. 161(1): pp. 69-78.
[6] Yang, R.Y., et al., Numerical simulation of particle dynamics in different flow regimes in a rotating drum. Powder Technology, 2008. 188(2): pp. 170-177.
[7] Xu, Y., et al., 2D DEM simulation of particle mixing in rotating drum: A parametric study. Particuology, 2010. 8(2): pp. 141-149.
[8] Jiang, M., et al., Enhancing mixing of particles by baffles in a rotating drum mixer. Particuology, 2011. 9(3): pp. 270-278.
[9] Komossa, H., et al., Transversal bed motion in rotating drums using spherical particles: Comparison of experiments with DEM simulations. Powder Technology, 2014. 264: pp. 96-104.
[10] Liu, P.Y., R.Y. Yang, and A.B. Yu, DEM study of the transverse mixing of wet particles in rotating drums. Chemical Engineering Science, 2013. 86: pp. 99-107.
[11] He, Y.R., et al., Solids Motion and Segregation of Binary Mixtures in a Rotating Drum Mixer. Chemical Engineering Research and Design, 2007. 85 (7): pp. 963-973.
[12] Demagh, Y., et al., Surface particle motions in rotating cylinders: Validation and similarity for an industrial scale kiln. Powder Technology, 2012. 224: pp. 260-272.
[13] Santos, D.A., et al., Experimental and CFD study of the hydrodynamic behavior in a rotating drum. Powder Technology, 2013. 250: pp. 52-62.
[14] Huang, A.-N., W.-C. Kao, and H.-P. Kuo, Numerical studies of particle segregation in a rotating drum based on Eulerian continuum approach. Advanced Powder Technology, 2013. 24 (1): pp. 364-372.
[15] Santos, D.A., et al., A hydrodynamic analysis of a rotating drum operating in the rolling regime. Chemical Engineering Research and Design, 2015. 94: pp. 204-212.
[16] Delele, M.A., et al., Studying the solids and fluid flow behavior in rotary drums based on a multiphase CFD model. Powder Technology, 2016. 292: pp. 260-271.
[17] Gidaspow, D., Multiphase flow and fluidization: continuum and kinetic theory descriptions. 1st ed. 1994, USA: Boston, Mass.
[18] Lun, C.K.K., et al., Kinetic theories for granular flow: Inelastic particles in Couette flow and slightly inelastic particles in a general flowfield. Journal of Fluid Mechanics, 1984. 140: pp. 223-256.
[19] Schaeffer, D.G., Instability in the evolution equations describing incompressible granular flow. Journal of Differential Equations, 1987. 66 (1): pp. 19-50.

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