تأثیر ایجاد ناهمواری در پایین دست سرریز اوجی در کنترل پرش هیدرولیکی

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشیار گروه عمران، دانشکده فنی و مهندسی، دانشگاه مراغه، مراغه، ایران

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

3 کارشناس ارشد مهندسی عمران سازههای هیدرولیکی، دانشگاه آزاد اسلامی واحد مراغه، مراغه، ایران.

چکیده

در این پژوهش، ناهمواری­ها در پایین­دست سرریز اوجی برای جریان­های مختلف شبیه­سازی عددی شده و اثر ناهمواری در تغییر رژیم جریان، پروفیل سطح آب و افت انرژی بررسی شده است. بر این اساس پس از ایجاد دامنۀ حل، مش­بندی و مشخص کردن شرایط مرزی، شبیه­سازی عددی با استفاده مدل آشفتگی k-e استاندارد اجرا و برای صحت­سنجی نتایج عددی از مدل آزمایشگاهی سرریز اوجی چاتیلا و تابارا(Chatila & Tabbara, 2004)  استفاده شده است. در ادامه نیز به تاثیر سه نوع ناهمواری­ در پایین­دست سرریز و مقایسه آن با حالت شاهد و بر مشخصات جریان پرداخته شده است. نتایج حاصل از این تحقیق نشان می‌دهد با افزایش ارتفاع ناهمواری‌ها میزان افت انرژی تا 80 درصد نیز افزایش می­یابد.به­طور متوسط نیز ناهمواری­های 3 و 4 که باعث تغییر رژیم جریان شده­اند و بین 50 تا 70 درصد افت انرژی ایجاد کرده­اند. افزایش دبی جریان بر پروفیل سطح آب و افت انرژی تاثیر مستقیم دارد. بر اساس نتایج به­دست آمده، اگر طراحی
حوضچۀ آرامش مد نظر باشد، ناهمواری‌ها با ارتفاع
Hd6/0 قادر به تغییر رژیم جریان هستند و به­عنوان موفق‌ترین طرح پیشنهاد می­شود.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of Roughness at Downstream of Ogee Spillway in Order to Hydraulic Jump Control

نویسندگان [English]

  • Rasoul Daneshfaraz 1
  • sina sadeghfam 2
  • Vahid Saei 3
1 Civil Eng. Depertment, Unv. of Maragheh
2 Assistant Professor, university of Maragheh, Faculty of Engineering.
3 Msc, water civil engineering, Maragheh branch, Islamic azad university, Maragheh, iran.
چکیده [English]

In this study, the roughness at downstream of ogee spillway has been simulated numerically for different flows, and the effects of roughness on the transformation of flow regime, the water surface profiles, and the energy losses also have been investigated. Hence, after solution domain generation, meshing, and specification of boundary conditions, the numerical simulation has been run by using k-e standard turbulence model, and in order to validation of the numerical results of the investigated ogee spillway, the experimental model of ogee spillway proposed by Chatila and Tabara (2004) has been used. Also, the effects of three types of roughness at downstream of this spillway were evaluated. The results indicated that by increasing the heigh of roughness, the energy loss increases up to 80 percent. The roughness types of 3 and 4, imposed the regime transformation and caused 70 to 50 percent, in average, energy losses respectively. Also, we found that increase in flow discharge affected directly the water surface profiles.  Results showed that if the design of stilling basin was considered, the roughness with a height of 0.6Hd had the ability of flow regime transformation and was evaluated as the most successful design.

کلیدواژه‌ها [English]

  • Energy Loss
  • Flow Regime
  • Water Surface Profile
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