شبیه‌سازی عددی جریان‌ گل‌آلود سه‌بعدی حاوی دو نوع ذره در یک کانال آزمایشگاهی در حضور مانع

نوع مقاله : مقاله پژوهشی

نویسندگان

1 مهندسی مکانیک، دانشگاه زنجان، زنجان، ایران

2 گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه زنجان

چکیده

در این پژوهش انتشار جریان چگال پیوسته سه‌بعدی حاوی دو نوع ذره در برخورد با مانع به روش گردابه‌های بزرگ و با استفاده از کد اپن فوم، به‌صورت عددی مدل‌سازی شده‌است. به علت تعداد زیاد ذرات معلق، از روش اویلری- اویلری استفاده شده است و برای هر نوع ذره یک معادله غلظت، که دارای پارامتر سقوط ذرات است، حل می‌شود. نتایج نشان می‌دهند که قبل از مانع تغییر چندانی در پروفیل سرعت جریان در حالت با مانع و بدون مانع ایجاد نمی‌شود، ولی حضور مانع سرعت ماکزیمم جریان را 10 درصد کاهش می‌دهد. همچنین بار ذرات معلق نیز در عرض کانال برروی مانع کاهش می‌یابد. در حالت شبه پایدار نهایی، غلظت ماکزیمم (بعد از مانع) 15/3 درصد نسبت به حالت بدون مانع کاهش یافته است. با افزایش قطر ذرات تا 20 و 30 میکرون، ماکزیمم غلظت به ترتیب 12/5 و 22/3 درصد افزایش می‌یابد. بار ذرات معلق نیز برای ذرات با قطر 20 و 30 میکرون به ترتیب 21 و 68 درصد کاهش می‌یابد. در نتیجه ذرات با قطر بیشتر، زودتر و بیشتر رسوب می‌کنند. تغییر غلظت ورودی در حالت ذره با قطر کمتر، موجب افزایش بار ذرات معلق به میزان 11/2 درصد شده و جریان قابلیت حمل بار معلق بیشتری را خواهد داشت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Simulation of Three-Dimensional and Bi-Disperse Particle-Laden Turbidity Current in an Experimental Channel in the Presence of an Obstacle

نویسندگان [English]

  • Saba Teymouri 1
  • Ehsan Khavasi 2
1 Department of Mechanical Engineering, University Of Zanjan, Zanjan, Iran.
2 Mechanical engineering department, University of Zanjan
چکیده [English]

In the present study, the propagation of a continuous three-dimensional, in collision with obstacle and bi-disperse particle-laden turbidity current with a large eddy simulation method was modeled using the OpenFOAM numerically. Due to the presence of a large number of suspended particles, the Eulerian-Eulerian method has been used and for each particle a concentration equation, which the particles settling velocity has been added to, is solved. The results show that before the obstacle, there is no significant change in the current velocity profiles in with and without obstacle state, but the presence of an obstacle decreases the maximum velocity by 10%, also the number of suspended particles on the obstacle decreases in channel width. In the final semi-stable state, the maximum concentration of 15.3% is reduced compared to the without obstacle state. By increasing the particle diameter to 20 and 30 microns, maximum concentration is increased by 12.5% and 22.3%, the number of suspended particles also decreases by 68% and 21%, respectively. As a result, particles with larger diameter precipitate more and rapidly. Changing the inlet concentration in the case of smaller diameter particle increases the number of suspended particles by 11.2% and current will have more capability for carrying suspended particles.

کلیدواژه‌ها [English]

  • density continuous current
  • obstacle
  • turbidity
  • particles
  • Large Eddy Simulation
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