مطالعه آزمایشگاهی تأثیر عوامل هیدرولیکی و هندسی تونل انتقال رسوب بر جریان و رسوب انتقال‌یافته

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری مهندسی عمران- آب و سازه‌های هیدرولیکی، دانشگاه صنعتی شاهرود، شاهرود، ایران

2 دانشیار گروه مهندسی عمران دانشگاه صنعتی شاهرود، شاهرود، ایران

3 دانشیار گروه آب و خاک دانشکده مهندسی کشاورزی دانشگاه شاهرود، شاهرود، ایران

چکیده

در چند دهه اخیر، هرچند سدسازی روند افزایشی داشته است، ولی متأسفانه اکثر این سدها در دوره بهره‌‌برداری با مشکل رسوب‌گذاری مواجه می‌باشند. به‌عنوان یک راه علمی می‌توان جهت رفع این مسئله به ساخت تونل‌های انتقال رسوب اشاره کرد. تونل‌ها کانال‌های انحرافی هستند که جریان حاوی رسوبات را از بالادست مخزن سد به پایین‌دست آن منتقل می‌نمایند. در این مطالعه آزمایشگاهی، تأثیر عرض کانال انحرافی بر میزان دبی و رسوب انحرافی به کانال فرعی بررسی شده است. در این راستا در سه عرض مختلف کانال انحرافی، متغیرهای عدد فرود جریان و عمق جریان مورد بررسی قرار گرفت. نتایج حاصله از این تحقیق بیانگر آن است که افزایش عدد فرود به‌طور متوسط باعث کاهش 20 درصدی دبی منحرف‌شده به کانال و کاهش 44 درصدی رسوب منحرف‌شده به کانال فرعی می‌شود. از طرفی کاهش 33 درصدی عرض کانال انحرافی می­تواند کاهش 5/8 درصدی دبی انحرافی به کانال فرعی را به دنبال داشته باشد و افزایش 50 درصدی عرض کانال انحرافی می‌تواند در افزایش 13 درصدی رسوب انحرافی به کانال فرعی مؤثر باشد. شاخص عملکرد بزرگ‌تر از 1 بوده و از مقدار 6/1 الی 77/3 متغیر است و درنتیجه کانال انحرافی 90 درجه عملکرد مناسبی در انتقال رسوب دارد. با کاهش عدد فرود و افزایش عمق جریان و با مقدار عرض بدون بعد کانال انحرافی برابر 41/0 می‌توان گزینه مطلوب در انتقال رسوب را فراهم نمود، به‌گونه‌ای که با کمترین میزان دبی انحرافی بیشترین مقدار رسوب منحرف شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Study of the Effects of Hydraulic and Geometric Parameters of the Sediment Transport Tunnel on the Deviation Flow and Transmitted Sediment

نویسندگان [English]

  • Pejman Aminian 1
  • Ahmad Ahmadi 2
  • Samad Emamgholizadeh 3
1 PhD Student,Department of Civil Engineering, Shahrood University of Technology, Shahrood, Iran
2 Associated Professor, Department of Civil Engineering, Shahrood University of Technology, Shahrood, Iran.
3 Associated Professor, Department of Agricultural Engineering Shahrood University of Technology, Shahrood, Iran
چکیده [English]

In recent decades, although dam construction has been increased, but most of them have experienced huge sedimentation problems during operation. To solve this problem scientifically and efficiently, Sediment Bypass Tunnels (SBTs) could be incorporated. SBTs are division channels that transfer the flow containing sediments from the upstream to the downstream of the dam reservoir. In this experimental study, the effect of division channel width on deviated flow rate and sediment rate into the secondary channels has been investigated. For this purpose, Froude number and flow depth as variables were studied in three different widths of the diversion channel. The results of this study reveals that increasing Froude number reduces the deviated flow rate and sediment rate to the lateral channel up to 20 and 44% respectively. On the other hand, 33% width reduction of the diversion channel could result a reduction of 8.5% in the deviated flow rate and 50% increase in the width could increase 13% the deviated sediment rate into the lateral channel. The performance index was greater than one and ranged from 1.6 to 3.77. Hence the 90-degree diversion channel has a good performance for sediment transportation. By decreasing Froude number and increasing flow depth in a diversion channel (with dimensionless width=0.41), it is possible to find the optimum choice for sediment transportation by which the highest sediments could be deviated by the lowest deviated flow rate.

کلیدواژه‌ها [English]

  • Sediment Bypass Tunnels (SBTs)
  • sediment transfer
  • secondary flow
  • deviated flow
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