مطالعه اثر باد بر رفتار هیدرودینامیکی جریان چگال رهاسازی توده

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی مکانیک، دانشگاه زنجان، زنجان، ایران

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

چکیده

در مطالعه حاضر انتشار جریان گل‌آلود رهاسازی توده به‌صورت دوبعدی، تحت تأثیر جریان باد با استفاده از نرم‌افزاری متن‌باز، مدل‌سازی شده است. جهت حل این مسئله از روش شبیه‌سازی گردابه‌های بزرگ به منظور مشاهده دقیق‌تر پدیده‌های آشفته، استفاده شده است. با توسعه حل‌گر دوفازی نرم‌افزار مذکور به‌گونه‌ای که معادلات روش حجم سیال با معادله اسکالر غلظت جفت شوند، مسئله سه‌فاز به‌صورت یک فاز مخلوط سیال چگال و آب خالص درکنار فاز هوا شبیه‌سازی می‌شود. نتایج نشان می‌دهد که افزایش سرعت باد سبب کاهش نیروی شناوری محرک جریان گل‌آلود و هم‌‌چنین افزایش درون‌آمیختگی می‌شود که معنای آن آلودگی سریع‌تر نواحی آبی است. این افزایش سرعت باد باعث افزایش تنش برشی دیوار نیز می‌شود با این تفاوت که مقدار تنش برشی دیوار در سرعت‌های باد کم، چشم‌گیر نیست و این خود مانع از تغییر قابل ملاحظه در رفتار رسوب‌گذاری جریان می‌شود. با بررسی رفتار رسوب‌گذاری جریان، مشاهده می‌شود که در سرعت‌های باد زیاد، جریان باد موافق با جریان گل‌آلود، تأثیرات زیان‌بارتری نسبت به جریان باد مخالف دارد و انباشت رسوب آن بیش‌تر است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Studying Wind Effect on the Hydrodynamic Behavior of Lock-Exchange Density Current

نویسندگان [English]

  • Parsa Nazmi 1
  • Ehsan Khavasi 2
  • Sadegh Rostami Dehjalali 1
1 Department of Mechanical Engineering, University Of Zanjan, Zanjan, Iran
2 Mechanical engineering department, University of Zanjan
چکیده [English]

In the present study, the two-dimensional lock-exchange turbidity current under the influence of wind flow is modeled using open-source software. To solve this, the large eddy simulation method has been used in order to observe turbulent phenomena more accurately. By developing the two-phase solver of the software so that the equations of the volume of fluid method are coupled with the scalar equation of concentration, the three-phase problem is simulated as a phase of a mixture of dense fluid and pure water next to the air phase. The results show that an increase in wind speed reduces the buoyancy force driving the turbidity current and increases the entrainment, which means faster pollution of water areas. This increase in wind speed also increases the wall shear stress, with the difference that the amount of wall shear stress at low wind speeds is not significant. So this prevents a significant change in the deposition behavior of the current. Studying the current's sedimentation behavior, showed that at high wind speeds, the co-current wind flow corresponding to the turbidity current has more harmful effects than the reverse wind flow and its sediment accumulation is getting higher.

کلیدواژه‌ها [English]

  • Wind flow
  • Turbidity current
  • Turbulent phenomena
  • Sedimentation
  • Volume of Fluid Method
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