تاثیر عمق آب پایین‌دست بر مشخصات پرش هیدرولیکی در امتداد سرریز جانبی

نویسندگان

1 دانش آموختهِ‌ کارشناسی ارشد رشته مهندسی عمران- آب، دانشکده فنی و مهندسی، دانشگاه رازی، کرمانشاه

2 استادیار گروه عمران- آب، دانشکده فنی و مهندسی، دانشگاه رازی کرمانشاه

چکیده

سرریز­ جانبی یکی از سازه­های انحراف آب است که به طور گسترده برای اهداف گوناگونی از جمله انحراف آب اضافی در سیستم­های جمع آوری فاضلاب شهری، شبکه­های آبیاری، کنترل ارتفاع سیلاب­ها و موارد دیگر به کار گرفته می­شود. در بعضی شرایط ممکن است جریان متغیر مکانی بر روی سرریز جانبی همراه با پرش هیدرولیکی باشد که این حالت کمتر مورد توجه محققین قرار­ گرفته است. در این مقاله پس از شبیه­سازی پرش هیدرولیکی با استفاده از نرم افزار Flow-3D و اعتبارسنجی مدل با استفاده از نتایج آزمایشگاهی، مشخص شد که مدل عددی قادر به شبیه­سازی مناسب پرش هیدرولیکی می­باشد. سپس تأثیر تغییر عمق پایین­دست بر خصوصیات پرش هیدرولیکی بررسی شد. با کاهش عمق پایین­دست، محل شروع پرش هیدرولیکی بسمت انتهای پایین­دست سرریز حرکت می­کند و با افزایش عمق پایین­دست پرش هیدرولیکی حذف می­گردد. با حرکت به سمت انتهای سرریز توزیع سرعت طولی به علت تشکیل ناحیه جدایی جریان در نزدیکی بسترکانال اصلی غیریکنواخت شده و نواحی با سرعت­های منفی در این ناحیه تشکیل می­شود.

کلیدواژه‌ها

عنوان مقاله [English]

The Effect of Downstream Water Depth on Hydraulic Jump Characteristics Along Side Weir

نویسندگان [English]

  • N Bagheri Seyyed Shekari 1
  • A Eghbalzadeh 2
  • M Javan 2
1 M.Sc. of Water Engr, Dept. of Civil Engineering. Razi Univ. Kermanshah, Iran
2 Assist. Prof., Department of Civil Engr, Razi Univ, Kermanshah, Iran
چکیده [English]

Side weir is one of the water diversion structures which is widely used for different purposes such as deviation of the excess water in the urban wastewater collection systems, irrigation networks, control of the floods’ elevation, etc. In some conditions, a spatially varied flow over the side weir might include hydraulic jump which has been less studied yet. In present study the hydraulic jump issue was investigated using a Flow-3D software model. The model was validated with experimental data and the results showed that the numerical model was able to simulate the hydraulic jump with reasonable accuracy. Then, the effect of the downstream water depth on the characteristics of the hydrulic jump was investigated. By decreasing the downstream water depth, the location of the hydraulic jump moved toward the weir downstream end while the hydraulic jump was removed by increasing the downstream water depth. By moving towards the end of the weir, the longitudinal velocity distribution became non-uniform due to formation of the separation zone near the main channel bed flow and the areas with negative velocities were formed.

کلیدواژه‌ها [English]

  • Downstream depth
  • Flow-3D
  • Hydraulic jump
  • Numerical simulation
  • Side weir

مراجع

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دانش آب و خاک
دوره 28، شماره 3
مهر 1397
صفحه 195-208

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