مقایسه استهلاک انرژی در صفحات مشبک افقی دوگانه و حوضچه‌های آرامش در پایین‌دست شیب‌شکن قائم

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استاد، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه مراغه

2 استادیار، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه مراغه، مراغه، ایران

3 گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه مراغه، مراغه، ایران

چکیده

هدف از تحقیق حاضر بررسی استهلاک انرژی صفحات مشبک دوگانه افقی نصب شده بر لبه شیب‌شکن قائم بوده و نتایج آن با نتایج حوضچه‌های آرامش استاندارد نوع یک، دو، سه و چهار مورد مقایسه قرار گرفت. تعداد 140 آزمایش مختلف بر روی صفحات مشبک دوگانه افقی نصب شده بر لبه شیب‌شکن قائم در فواصل نسبی بین صفحات 25/0، 33/0 و 5/0، تخلخل 40 و 50 درصدی صفحات و دو ارتفاع شیب‌شکن 20 و 25 سانتی­متری انجام شد. نتایج نشان داد که فاصله نسبی و تخلخل صفحات مشبک افقی دوگانه تاثیر چندانی بر انرژی باقی­مانده نسبی نرمال جریان و عمق نسبی پایین‌دست نداشته ولی با این حال با افزایش فاصله نسبی و درصد تخلخل صفحات، طول حوضچه آرامش شیب‌شکن کاهش می‌یابد. در مقایسه با حوضچه‌های آرامش نیز، به­کارگیری صفحات مشبک افقی دوگانه سبب کاهش طول حوضچه آرامش شیب‌شکن شده و انرژی نسبی باقی‌مانده و عمق نسبی پایین‌دست به­ترتیب بیش از 35 و 49 درصد کاهش یافت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Comparison of Energy Dissipation by Double Horizontal Screen and Stilling Basins at Vertical Drop Downstream

نویسندگان [English]

  • Rasoul Daneshfaraz 1
  • Mahdi Majedi Asl 2
  • Shaban Razmi 3
1 Professor , Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.
2 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.
3 Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.
چکیده [English]

The aim of this study was to evaluate and compare the double horizontal screens with four types of stilling basin (I, II, III and IV) at vertical drop downstream in terms of energy dissipation. A total of 140 different experiments were performed on a vertical drop equipped with double horizontal screens (with 40 and 50% porosity) at relative spaces of 0.25, 0.33 and 0.5 between the screens, and two drop height of 20 and 25 cm. The results showed that the relative spacing and porosity of the double horizontal screen do not have a significant effect on the residual energy and the relative depth of downstream, however, the length of drop stilling basin is decreased with increasing the relative spacing and porosity of screen. In compared to the stilling basins, the use of double horizontal screens reduced the length of drop stilling basin and the residual energy and relative depth of downstream is reduced by more than 35 and 49%, respectively.

کلیدواژه‌ها [English]

  • normalized residual energy
  • double horizontal screens
  • stilling basin
  • vertical drop
  • drop length
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