ارتقاء استهلاک انرژی سرریزهای پلکانی با استفاده از فرآیند پله – حوضچه‌ای رودخانه‌های کوهستانی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکترای /سازه‌های هیدرولیکی، بخش‌عمران، دانشکده مهندسی، دانشگاه‌شیراز

2 استاد/ بخش عمران - دانشکده مهندسی- دانشگاه شیراز

چکیده

یکی از بارزترین مشخصه‌های کاربردی سرریز پلکانی در مقایسه با سرریزهای دیگر، استهلاک انرژی قابل ملاحظه در طول مسیر سرریز است. بنابراین با توجه به ویژگی اصلی سرریز پلکانی، فهم کاملتر چگونگی استهلاک انرژی، برآورد میزان و نهایتاً افزایش مقدار آن، محور بیشتر تحقیقات بوده است. در این تحقیق ضمن ارزیابی چگونگی و اندازه‌گیری میزان استهلاک انرژی سرریز پلکانی معمول، با توجه به اهمیت زیاد سهم زبری فرم بستر در میزان استهلاک انرژی با الهام از الگوی طبیعی فرم بستر پایدار پله- حوضچه‌ای در رودخانه‌های کوهستانی با شیب زیاد، اقدام به ارائه طرح جدید سرریز پلکانی با بستر ترکیبی پله- حوضچه‌ای گردیده است. در این راستا، شش الگوی مختلف تحت دو شیب مختلف سرریز و شش دبی متفاوت عبوری (جمعاً 72 حالت) مورد بررسی آزمایشگاهی قرار گرفته است. نتایج آزمایشگاهی در مقایسه آزمایشگاهی با سرریز پلکانی معمولی با خیز پلکان یکسان ، افزایش استهلاک انرژی تا حداکثر 30 درصد را در سرریز پلکانی با فرم پله- حوضچه‌ای ترکیبی نشان می‌دهد که این نتیجه خود تاییدی در راستای بهینه بودن فرآیندهای طبیعی و راندمان بالای مدل سرریز پلکانی مرکب بعنوان یک مدل جدید سرریز پلکانی است. 

کلیدواژه‌ها


عنوان مقاله [English]

Energy Loss Promotion of Stepped Spillways Based On Step-Pool Formation In High Gradient Mountain Streams

نویسندگان [English]

  • A Mardashti 1
  • N Talebbeydokhti 2
1 Ph. D. Student of Civil Eng. Dep., Engineering School, Shiraz University
2 Prof. of Civil Eng. Dep., Engineering School, Shiraz University
چکیده [English]

The most important characteristic of a stepped spillway compared to other kinds of spillways is the high energy dissipation. The understanding of head loss, evaluation and promotion of energy dissipation are the basis of more research. In this study, a new step-pool formation is designed in stepped spillway based on natural high gradient mountain stream bed formation. Residual energy downstream of both the step-pool stepped spillway and the normal stepped spillway are measured in the hydraulic laboratory of the School of Engineering of ShirazUniversity. For new design, the experiments were made at two slopes, under six discharges and six step-pool configurations. Therefore, a total of 72 tests were performed. Based on this laboratory results, it was concluded that the step-pool (compound) stepped spillway caused an extra 30% reduction in energy dissipation compared to the simple stepped spillway. This result confirms the optimization of natural step-pool formation for stepped spillways.

کلیدواژه‌ها [English]

  • Energy dissipation
  • energy loss
  • Stepped spillway
  • Step-pool
  • Mountain stream
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