مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

شبیه‌سازی دو بعدی برخورد گوه به سیال نیوتنی و سیال غیرنیوتنی از نوع هرشل‌بالکلی-دایلاتنت با استفاده از روش WCSPH

نویسندگان
دانشگاه صنعتی شیراز
چکیده
مسئله برخورد گوه به سطح آزاد سیال کاربردهای مهمی در زمینه‌های مختلف مهندسی و در صنایع دریایی دارد و محاسبه نیروی وارد به گوه به خصوص در لحظات اولیه برخورد مورد علاقه بسیاری از محققان می باشد. هدف این مقاله حل عددی برخورد گوه به سیال نیوتنی و سیال غیرنیوتنی هرشل بالکلی دایلاتنت با استفاده از روش لاگرانژی هیدرودینامیک ذرات هموار با تراکم پذیری ضعیف است. برخی سیالات غیرنیوتنی مانند سیال دایلاتنت یا هرشل بالکلی دایلاتنت به دلیل داشتن خاصیت غلیظ شوندگی در محل اعمال تنش، در برابر ورود گوه به سیال از خود مقاومت نشان می دهند. در این تحقیق از الگوریتم پیش بینی و تصحیح جهت حل معادلات استفاده شده است. جهت ایجاد پایداری از تصحیح چگالی(در سیالات نیوتنی و غیرنیوتنی) و ویسکوزیته مصنوعی (فقط در سیال نیوتنی) استفاده شده است. جهت اعتبار سنجی سطح آزاد و بررسی صحت استفاده از سیال هرشل بالکلی دایلاتنت مسئله شکست سد با استفاده از شرط مرزی انعکاسی حل شده است. در ادامه مسئله برخورد گوه به سیال نیوتنی صحت سنجی شده و با تغییر سه پارامتر لزجت، تنش تسلیم و توان نرخ برش در سیال هرشل بالکلی و استفاده از شرط مرزی نیروی دافعه موناقان مسئله برخورد شبیه سازی شده و نتایج آن به صورت مقادیر نیرو، ضریب فشار و سرعت گوه با هم و همچنین با نتایج آزمایشگاهی سیال نیوتنی مقایسه شده است. جهت صرفه‌جویی در زمان، مقادیر اولیه فشار هیدرواستاتیکی از ابتدا به سیال اعمال می شود.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

2D Simulation of a wedge impact problem into the Newtonian and Herschel Bulkley Dilatant non-Newtonian fluids, using WCSPH method

نویسندگان English

jafar gerdabi
Amir H. Nikseresht
Mechanical Engineering, Shiraz University of Technology
چکیده English

The impact problems associated with water entry have important applications in various aspects of naval architecture and ocean engineering. Also the calculation of impact force is favorable to many researchers. The purpose of this study is to simulate the impact problem of a wedge into the Newtonian and also Herschel Bulkley dilatant non-Newtonian fluids using the Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) method. Some non-Newtonian fluids, such as dilatant or Herschel Bulkley dilatant fluids can resist against the wedge entry due to their shear thickening effect. In this research a prediction and correction algorithm is used to solve the governing equations. Density correction and also artificial viscosity (which is used only in Newtonian fluids) are used to prevent the numerical instability. To show the validation, ability and robustness of the generated code to capture the free surface in Newtonian and non-Newtonian fluids, the dam break problem with the image boundary condition is simulated. After validating the code and the used method, the impact problem of a wedge with Monaghan repulsive force boundary condition in Newtonian and Herschel Bulkley Dilatant non-Newtonian fluids are investigated and the results of force, pressure coefficient and velocity of the wedge are presented and compared with experiments and also with each other. To save time, the initial values of hydrostatic pressure are imposed as an initial condition of the fluid.

کلیدواژه‌ها English

Impact of a wedge
Non-Newtonian Fluid
Herschel Bulkley Dilatant
WCSPH method
Repulsive force
[1] R. P. Chhabra, J. F. Richardson, Non-Newtonian flow in the process industries: fundamentals and engineering applications, pp. 1-36, Great Britain: Butterworth-Heinemann, 1999.
[2] F. Irgens, Rheology and Non-Newtonian Fluids, pp. 1-22, Norway: Springer, 2014.
[3] L. B. Lucy, A numerical approach to the testing of the fission hypothesis, The Astronomical Journal, Vol. 82, No. 2, pp. 1013-1024, 1977.
[4] R. A. Gingold, J. J. Monaghan, Smoothed particle hydrodynamics: theory and application to non-spherical stars, Monthly Notices of the Royal Astronomical Society, Vol. 181, No. 3, pp. 375-389, 1977.
[5] G. Oger, M. Doring, B. Alessandrini, P. Ferrant, Two-dimensional SPH simulations of wedge water entries, Journal of Computational Physics, Vol. 213, No. 2, pp. 803-822, 2006.
[6] G. Kai, L. Hua, B. l. Wang, Water entry of a wedge based on SPH model with an improved boundary treatment, Journal of Hydrodynamics, Ser. B, Vol. 21, No. 6, pp. 750-757, 2009.
[7] P. K. Koukouvinis, J. S. Anagnostopoulos, D. E. Papantonis, Simulation of 2D wedge impacts on water using the SPH-ALE method, Acta Mechanica, Vol. 224, No. 11, pp. 2559, 2013.
[8] J. Vila, On particle weighted methods and smooth particle hydrodynamics, Mathematical Models and Methods in Applied Sciences, Vol. 9, No. 02, pp. 161-209, 1999.
[9] G. Chen, Y. Li, Investigation of free surface flow in wedge water entry problem using Smoothed Particle Hydrodynamics method, Proceeding of the OCEANS Conference, Shanghai: IEEE, pp. 1-7, 2016.
[10] L. Ma, H. Liu, Numerical study of 2-D vertical Water-entry problems using Two-phase SPH method, International Journal of Offshore and Polar Engineering, Vol. 27, No. 02, pp. 160-167, 2017.
[11] H. Ghazizade-Ahsaee, A. Nikseresht, Two-phase flow analysis of a symmetric water impact problem of a flying boat, considering dynamic equations, Proceeding of the 9th Iranian Aerospace Society Conference, Tehran, Iran, February 8-10, 2010.
[12] A. H. Nikseresht, H. Ghazizade-Ahsaee, Numerical simulation of three-dimensional dynamic motion of a standard NACA model in an impact problem, International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 4, pp. 190-194, 2012.
[13] R. Shademani, P. Ghadimi, Asymmetric water entry of twin wedges with different deadrises, heel angles, and wedge separations using finite element based finite volume method and VOF, Journal of Applied Fluid Mechanics, Vol. 10, No. 1, 2017.
[14] R. Zhao, O. Faltinsen, J. Aarsnes, Water entry of arbitrary two-dimensional sections with and without flow separation, Proceedings of the 21st Symposium on Naval Hydrodynamics Conference, Norway: National Academy Press, pp. 408-423, 1966.
[15] R. Zhao, O. Faltinsen, Water entry of two-dimensional bodies, Journal of Fluid Mechanics, Vol. 246, No. 1, pp. 593-612, 1993.
[16] G.-R. Liu, M. B. Liu, Smoothed Particle Hydrodynamics: A Meshfree Particle Method, pp. 1-56, Singapore: World Scientific, 2003.
[17] A. Vorobyev, A Smoothed Particle Hydrodynamics Method for the Simulation of Centralized Sloshing Experiments, pp. 24-27, Germany, KIT Scientific Publishing, 2012.
[18] Z.-B. Wang, R. Chen, H. Wang, Q. Liao, X. Zhu, S.-Z. Li, An overview of smoothed particle hydrodynamics for simulating multiphase flow, Applied Mathematical Modelling, Vol. 40, No. 23, pp. 9625-9655, 2016.
[19] A. Zhang, P. Sun, F. Ming, An SPH modeling of bubble rising and coalescing in three dimensions, Computer Methods in Applied Mechanics and Engineering, Vol. 294, No. 1, pp. 189-209, 2015.
[20] S. Farzin, Y. Hassanzadeh, M. T. Aalami, R. Fatehi, An implicit incompressible SPH method for free surface flow problems, Modares Mechanical Engineering, Vol. 14, No. 4, pp. 99-110, 2014. (in Persianفارسی )
[21] J. P. Morris, P. J. Fox, Y. Zhu, Modeling low Reynolds number incompressible flows using SPH, Journal of Computational Physics, Vol. 136, No. 1, pp. 214-226, 1997.
[22] M. Gesteira, B. Rogers, R. Dalrymple, A. Crespo, M. Narayanaswamy, User Guide for the SPHysics code, pp. 1-34, Manchester: University of Manchester, 2010.
[23] J. J. Monaghan, Simulating free surface flows with SPH, Journal of Computational Physics, Vol. 110, No. 2, pp. 399-406, 1994.
[24] A. Xenakis, S. Lind, P. Stansby, B. Rogers, An incompressible SPH scheme with improved pressure predictions for free-surface generalised Newtonian flows, Journal of Non-Newtonian Fluid Mechanics, Vol. 218, No. 1, pp. 1-15, 2015.
[25] S. Hosseini, M. Manzari, S. Hannani, A fully explicit three-step SPH algorithm for simulation of non-Newtonian fluid flow, International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 17, No. 7, pp. 715-735, 2007. (in Persian فارسی )
[26] S. Farzin, Y. Hassanzadeh, M. T. Aalami, R. Fatehi, Development of Two Incompressible SPH methods to simulate sediment-laden free surface flows, Modares Mechanical Engineering, Vol. 14, No. 12, pp. 91-103, 2015.
[27] D. Komatina, M. Jovanovic, Experimental study of steady and unsteady free surface flows with water-clay mixtures, Journal of Hydraulic Research, Vol. 35, No. 5, pp. 579-590, 1997.