بررسی آزمایشگاهی عملکرد آبشکن باز و بسته بر الگوی جریان و توپوگرافی بستر در کانال با بستر فرسایش‌پذیر

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشگاه بوعلی دانشکده مهندسی گروه عمران عضو هیئت علمی

2 گروه عمران، دانشکده فنی و مهندسی، دانشگاه بوعلی سینا، همدان، ایران.

3 عمران مهندسی دانشگاه بوعلی سینا همدان ایران

4 عمران دانشکده مهندسی دانشگاه بوعلی سینا همدان ایران

چکیده

فرسایش بستر و کناره­های رودخانه یکی از عواملی است که باعث تغییرات مورفولوژی رودخانه­ها می­شود. عمق آبشستگی معرف میزان پتانسیل تخریب جریان در اطراف سازه­های هیدرولیکی واقع در مسیر جریان است. بنابراین تعیین عمق آبشستگی و سرعت جریان، امری ضروری می‌باشد. در این مطالعه، نتایج آزمایشگاهی تغییرات توپوگرافی بستر و الگوی جریان در اطراف موانع نفوذناپذیر و موانع نفوذپذیر با یکدیگر مقایسه شده است. برای موانع نفوذپذیر از دو نوع موانع توری­سنگی و موانع میله­ای یک و دو ردیفه با زاویه 90 درجه نسبت به امتداد جریان استفاده شده است. در استفاده از موانع میله­ای دوردیفه، دو حالت قرارگیری میله­ها به­صورت در امتداد هم و زیگزاگی مورد نظر قرار گرفته است. آزمایش­ها در یک کانال مستطیلی با بستر متحرک به عرض 60 سانتی‌متر و دبی 28 لیتر بر ثانیه و عدد فرود 26/0 انجام پذیرفت. نتایج نشان داد روند تغییر حداکثر عمق آبشستگی با افزایش نفوذپذیری، کاهشی است. در موانع توری‌سنگی نسبت به موانع میله‌ای با نفوذپذیری یکسان، آبشستگی­ به مراتب بیشتر است. همچنین اثر افزایش فاصله ردیف‌های موانع دو ردیفه بر مقدر حداکثر عمق آبشستگی برای حالت زیگزاگی، افزایشی و برای حالت در امتداد هم، کاهشی می­باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Investigation of Permeable and Impermeable Groines Performance on Flow Pattern and Bed Topography in Erodible Channel

نویسندگان [English]

  • Majid Fazli 1
  • Sahar Ansary 2
  • Zainab Badp 3
  • sedighe pazin 4
1 civil engineering grope engineering faculty buali sina university
2 Department of Civil, Faculty of Technical and Engineering, Bu-ali Sina University, Hamedan, Iran.
3 civil engineering department faculty of engineering Bu ali sina university hamedan Iran
4 civil engineering department faculty of engineering Bu ali sina university hamedan Iran
چکیده [English]

The erosion of riverbeds is one of the factors that causes changes in the morphology of rivers. Scour depth represents the amount of potential degradation of the flow around hydraulic structures located in the flow path. Therefore, it is necessary to determine the scour depth and flow rate. In this study, the experimental results of bed topography changes and flow patterns around impermeable and impermeable groines are compared. For permeable groines, two types of gabion groines and one and two-row groines with a 90 degree angle to the flow were used. In the use of two-row groine, the two positions are considered parallel and zigzag. Experiments were performed in a rectangular channel with a moving bed of 60 cm width and a flow rate of 28 lit/s and Froude number of 0.26. The results showed that the trend of maximum scour depth change with increasing permeability decreased. The scour depth in gabion groines is much higher than rod groines with the same permeability. Also, the effect of increasing the row spacing of two-row groines on the prediction of the maximum scour depth for the zigzag type is additive and for the parallel type it is decreasing.

کلیدواژه‌ها [English]

  • permeable groin
  • gabion
  • one and two row
  • Flow pattern
  • Scouring
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