تحلیل عددی تهنشینی ذرات داخل اتاق بااستفاده‌از مدل ادی‌های بزرگ بر پایۀ روش شبکۀ بولتزمن

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشگاه بجنورد

2 دانشگاه شهیدباهنر کرمان

3 کلارکسون امریکا

4 شهیدباهنر کرمان

چکیده

در این مقاله ته‌نشینی ذرات با اندازه‌های مختلف (10 نانومتر تا 10 میکرومتر) داخل اتاق با استفاده از مدل ادی‌های بزرگ و زمان آرامش چندگانه بر پایۀ روش شبکۀ بولتزمن مورد بررسی قرار گرفته است و اثر نیروهای بویانسی، درگ و برونین بر روی ته‌نشینی ذرات بر روی دیواره‌های مختلف اتاق اداری تحلیل شد. برای مدل کردن ادی‌های کوچک از مدل بهبودیافته اسماگورنسکی استفاده شد. برای بررسی ته‌نشینی ذرات داخل اتاق، تعداد 144 ذره در هر بازه زمانی 05/0 ثانیه از دریچه ورودی جریان به داخل اتاق تزریق شد و بعد از گذشت 30 ثانیه تزریق ذره متوقف گردید، در مجموع 86400 ذره وارد اتاق شد. نتایج به‌دست آمده نشان دادند که روش عددی مورد استفاده همخوانی خوبی با روش‌های عددی و آزمایشگاهی گذشته دارد. تعداد ذرات ته‌نشین شده بر روی دیواره‌های مختلف اتاق بر حسب زمان محاسبه گردید و مشاهده شد که تعداد ذرات ته‌نشین شده به مرور زمان افزایش می‌یابد و ته‌نشینی ذرات با اندازه بزرگتر بیشتر می‌باشد. تراکم ذرات داخل اتاق بر حسب زمان نشان داده شد. لحظه شروع تزریق ذرات به داخل اتاق، تراکم آنها در ناحیه ورودی بیشتر می‌باشد و به مرور زمان تراکم در نواحی دور از ورودی جریان افزایش می‌یابد. نتایج به‌دست آمده از این پژوهش در طراحی سیستم‌های تهویه مطبوع اتاق‌های اداری و بیمارستانی کاربرد قابل توجهی خواهد داشت.

کلیدواژه‌ها


عنوان مقاله [English]

Numerical Investigation of Particle Deposition in a Room using Large Eddy Simulation based on Lattice Boltzmann Method

نویسندگان [English]

  • Hasan Sajjadi 1
  • Mazyar Salmanzadeh 2
  • Goodarz Ahmadi 3
  • Saeed Jafari 4
1 University of Bojnord
2 Shahid Bahonar
3 Clarkson
4 Shahid Bahonar
چکیده [English]

In this paper the Multi Relaxation Time Lattice Boltzmann Method in conjunction with the Large Eddy Simulation model was used to study the particle deposition in a room  with various diameters (10nm-10µm)and the effect of buoyancy, drag and Brownian forces to particle deposition on the different walls of the room has been investigated.  The sub-grid scale turbulence effects were simulated through a shear-improved Smagorinsky model. To simulate the particle deposition in the room, the particle injection process was initiated with 144 particles injected uniformly at the inlet with the same velocity as the airflow at every 0.05s; particle injection was stopped after 30s. Therefore, a total of 86400 particles were injected into the room. The present simulation results for the airflow showed good agreement with the experimental data and the earlier numerical results. The simulated results for particle dispersion and deposition showed that the numbers of deposited particles on the walls increases by augmentation of the time. When the particle injection started the concentration in the inlet jet region is more than other zones and that increases in the region far from the inlet by time. Present results will be interesting for designing air condition systems in the office and hospitals rooms.

کلیدواژه‌ها [English]

  • Lattice Boltzmann method
  • large eddy simulation
  • Particle Deposition
  • Shear Improved Smagorinsky Model
1. Sajjadi, H., Salmanzadeh, M., Ahmadi, G. and Jafari, S., “Combination of Lattice Boltzmann Method and RANS Approach for Simulation of Turbulent Flows and Particle Transport and Deposition”, Particuology, Vol. 30, pp. 62-72, (2017).
2. Jiang, J.B., Wang, X.L., Sun, Y.Z. and Zhang, Y.H., “Experimental and numerical study of airflows in a full-scale room”, ASHRAE Transactions, Vol. 115, pp. 867–886, (2009).
3. Smargorinsky, J., “General circulation experiment with the primitive equations”, Monthly Weather Review, Vol. 91, pp. 99–164, (1963).
4. Sukop, M. C. and Thorne Jr, D. T., “Lattice Boltzmann Modeling: An Introduction for Geoscientists and Engineers”, New York, Springer, (2006).
5. Succi, S., “The Lattice Boltzmann Equation for Fluid Dynamics and Beyond”, Oxford University Press: Oxford, (2001).
6. Sajjadi, H., Salmanzadeh, M., Ahmadi, G. and Jafari, S., “Turbulent Indoor Airflow Simulation Using Hybrid LES/RANS Model Utilizing Lattice Boltzmann Method”, Computers and fluids, Vol. 150, pp. 66-73, (2017).
7. Jafari, S. and Rahnama, M., “Shear-improved Smagorinsky modeling of turbulent channel flow using generalized Lattice Boltzmann equation”, International Journal for Numerical Methods in Fluids, Vol. 67, pp. 700–712, (2011).
8. Sajjadi, H., Gorji, M., Kefayati, G.H.R. and Ganji, D.D., “Lattice Boltzmann Simulation of Turbulent Natural Convection in Tall Enclosures Using Cu/Water Nanofluid”, Numerical Heat Transfer, Part A, Vol. 62, pp. 512–530, (2012).
9. Krafczyk, M., Tölke, J., Luo, L.S., “Large eddy simulation with a multiple-relaxationtime LBE model”, International Journal of Modern Physics B, Vol. 17, pp. 33-39, (2003).
10. Premnath, K. N., Pattison, M.J. and Banerjee, S., “Generalized Lattice Boltzmann equation with forcing term for computation of wall bounded turbulent flows”, Physical Review E, Vol. 79, pp. 026703-1–026703-19, (2009).
11. Salmanzadeh, M., Rahnama, M. and Ahmadi, G., “Effect of subgrid scales on large eddy simulation of particle deposition in a turbulent channel flow”, Journal of Aerosol Science and Technology, Vol. 44, pp.796–806, (2010).
12. Jafari, S., Salmanzadeh, M., Rahnama, M. and Ahmadi, G., “Investigation of particle dispersion and deposition in a channel with a square cylinder obstruction using the lattice Boltzmann method”, Journal of Aerosol Science, Vol. 41, pp. 198–206, (2010).
13. Ding, L., Fung, J.L.S., Seepana, S. and Lai, A.C.K., “Numerical study on particle dispersion and deposition in a scaled ventilated chamber using a lattice Boltzmann method”, Journal of Aerosol Science, Vol. 47, pp. 1–11, (2012).
14. Samari Kermani, M., Jafari, S., Rahnama, M. and Salmanzadeh, M., “Particle Tracking in Large Eddy Simulated Turbulent Channel Flow Using Generalized Lattice Boltzmann Method”, Particulate Science and Technology, Vol. 32, pp. 404–411, (2014).
15. Sajjadi, H., Salmanzadeh, M., Ahmadi, G. and Jafari, S., “Simulations of Indoor Airflow and Particle Dispersion and Deposition by the Lattice Boltzmann Method Using LES and RANS Approaches”, Building and Environment, Vol. 102, pp. 1-12, (2016).
16. Frisch, U., Hasslacher, B. and Pomeau, Y., “Lattice-Gas Automata For Navier-Stokes Equation”, Physics Review Letter, Vol. 56, pp. 1505-1508, (1986).
17. d’Humières, D., Ginzburg, I., Krafczyk, M., Lallemand, P. and Luo, LS., “Multiple-relaxation-time Lattice Boltzmann models in three dimensions”, Philosophical Transactions of the Royal Society A, Vol. 360, pp. 437–452, (2002).
18. Yu, H., Luo, L.S. and Girimaji, S., “LES of turbulent square jet flow using an MRT Lattice Boltzmann model”, Computers and Fluids, Vol. 35, pp. 957–965, (2006).
19. Pattison, M.J., Premnath, K.N. and Banerjee, S., “Computation of turbulent flow and secondary motions in a square duct using a forced generalized Lattice Boltzmann equation”, Physical Review E, Vol. 79, pp. 026704-1–026704-13, (2009).
20. Premnath, K. N., Pattison, M. J. and Banerjee, S., “Dynamic subgrid scale modeling of turbulent flows using Lattice– Boltzmann method”, Physica A, Vol. 388, pp. 2640–2658, (2009).
21. Tian, L. and Ahmadi, G., “Particle deposition in turbulent duct flows comparisons of different model predictions”, Journal of Aerosol Science, Vol. 38, pp. 377–397, (2007).
22. Zhang, H. and Ahmadi, G., “Aerosol particle transport and deposition in vertical and horizontal turbulent duct flow”, Journal of Fluid Mechanics, Vol. 406, pp. 55–80, (2000).
23. Li, A. and Ahmadi, G., “Deposition of aerosols on surfaces in a turbulent channel flow”, International Journal of Engineering Science, Vol. 31, pp.435–451, (1993).
24. Posner, J.D., Buchanan, C.R. and Dunn-Rankin, D., “Measurement and prediction of indoor air flow in a model room”, Energy and Buildings, Vol. 35, pp. 515–526, (2003).
25. Tian, Z.F., Tu, J.Y., Yeoh, G.H. and Yuen R.K.K., “On the numerical study of contaminant particle concentration in indoor air flow”, Building and Environment, Vol. 41, pp. 1504–1514, (2006).
26. Hardalupas, Y. and Taylor, A., “On the measurement of particle concentration near a stagnation point”, Experiments in Fluids, Vol. 8, pp. 113–118, (1998).
27. Zhu, J., Rudoff, R., Bachalo, E. and Bachalo, W.N., “Number density and mass flux measurements using the phase Doppler particle analyzer in reacting and non-reacting swirling flows”, In: AIAA, Aerospace sciences meeting, (1993).
28. Salmanzadeh, M., Zahedi, Gh., Ahmadi, G., Marr, D.R. and Glauser, M., “Computational modeling of effects of thermal plume adjacent to the body on the indoor airflow and particle transport”, Journal of Aerosol Science, Vol. 53, pp. 29–39, (2012).