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

نوع مقاله : مقاله پژوهشی

نویسندگان

• حسن سجادی ¹
• مازیار سلمان زاده ²
• گودرز احمدی ³
• سعید جعفری ⁴

¹ دانشگاه بجنورد

² دانشگاه شهیدباهنر کرمان

³ کلارکسون امریکا

⁴ شهیدباهنر کرمان

10.22067/fum-mech.v30i2.68789

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

• روش شبکه بولتزمن
• مدل حل ادی های بزرگ
• پخش و ته نشینی ذرات
• مدل بهبودیافته اسماگورنسگی

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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

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