بررسی آزمایشگاهی تأثیر ارتفاع دریچه تخلیه کننده بر غلظت جریان غلیظ خروجی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری/ سازه‌های آبی، دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

2 استاد/ گروه سازه‌های آبی، دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

3 استادیار/ گروه سازه‌های آبی، دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

چکیده

جریان‌های غلیظ یکی از عوامل مؤثر بر رسوب‌گذاری در مخازن سدهاست که یکی از مشکلات مهم در مدیریت منابع آب می‌باشند. گشــودن دریچه‌های تحتانی سد، روش متداول تخلیه این جریان‌ها و حفظ حجم مفید مخزن می‌باشد انتخاب ارتفاع مناسب دریچه تخلیه جریان بر روی دیواره سد دارای کاربردهای مختلفی در مدیریت مخازن سدها دارد که می‌تواند بر کیفیت آب خروجی از سدها تأثیر عمده داشته باشد. بنابراین در این تحقیق سعی شده به بررسی تأثیر ارتفاع دریچه تخلیه کننده بر غلظت جریان غلیظ خروجی پرداخته شود. بدین منظور چهار دریچه در ارتفاعات 5، 15، 25 و 40 درصد نسبت به عمق سیال پیرامون بر روی یک دیواره در انتهای فلوم کار گذاشته شد. جریان غلیظ ورودی با سه غلظت 5، 15 و 30 گرم در لیتر با یک دبی ثابت تزریق گردید. نتایج نشان می‌دهد که در موقعیت که دریچه در ارتفاعی نظیر 5 درصد عمق سیال پیرامون قرار بگیرد مقدار غلظت خروجی به‌طور متوسط 10 درصد بیشتر از غلظت متوسط جریان پشت دریچه می‌باشد و با افزایش مدت زمان باز نگه داشتن دریچه در اعماق مختلف به دلیل خروج جریان بیشتر، غلظت و درنتیجه راندمان تخلیه جریان غلیظ 40 درصد افزایش می‌یابد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Investigation on the Effects of Selective Withdrawal Gate on Venting of Turbid Density Current

نویسندگان [English]

  • M. Zayeri 1
  • M. Ghomeshi 2
  • M. Shafaei Bajestan 2
  • A. Fathi 3
1 Ph.D Student of Hydraulic Structures, Shahid Chamran University, Ahwaz, Iran.
2 Professor, Faculty of Water Structures Engineering, Shahid Chamran University, Ahwaz, Iran
3 Assistant Professor, Faculty of Water Structures Engineering, Shahid Chamran University, Ahwaz, Iran
چکیده [English]

Turbidity currents are one of factors affecting in sedimentation and reducing the water capacity of reservoirs and useful life of dams. Opening bottom gates is a conventional method of this currents venting and preservation of the useful volume of the reservoir. Choose a suitable height of gate on the dam has variety of applications in the management of reservoirs that can have a major impact on the water quality. So this study have tried to investigate the effect of selective withdrawal gate on venting of turbid density current through reservoir’s outlet. For this purpose Four gates established at height of 5, 15, 25 and 40 percent compared to the depth of the ambient fluid on a wall in the end of flume. The Turbidity current input with concentrations of 5, 15 and 30 g/L were injected with a constant volume flow rate. The results show when the position of the gate is placed at 5 percent of the fluid depth, the amount of output concentration averagely 10 percent higher than of input concentration of turbidity current. with increasing duration of keeping open the outlate gates, venting efficiency will increasing of 40 percent.

کلیدواژه‌ها [English]

  • turbid density current
  • Reservoir managment
  • venting efficiency
  • reservoir outlet
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