بررسی آزمایشگاهی موقعیت سازه سرریز- دریچه استوانه‌ای در راستای عمود بر جریان بر روی ضریب دبی جریان

نویسندگان

چکیده

یکی از انواع مدل‌های سازه ترکیبی،‏ سرریز- دریچه استوانه‌ای است که دارای ویژگی‌هایی ازجمله هزینه کم،‏ طراحی آسان،‏ راحتی ساخت و ضریب دبی بالا است. در این مطالعه به بررسی آزمایشگاهی موقعیت قرارگیری سازه استوانه‌ای در راستای عمود بر جریان بر روی ضریب دبی عبوری از سازه پرداخته شده است. آزمایش‌ها در فلومی به طول 5‎/7 متر و عرض 40 سانتی‌متر و با استفاده از مدل‌های استوانه‌ای از جنس لوله پلاستیکی با قطرهای 50،‏ 75،‏ 110 و 125 میلی‌متر انجام شده است. طراحی آزمایش‌ها با میزان بازشدگی‌های مختلف از صفر تا 60 میلی‌متر (رسیدن به دریچه استوانه‌ای با توجه به قطر و دبی موجود) انجام شده است. نتایج نشان داد که بیشترین و کمترین ضریب دبی به‌ترتیب در سازه‌های سرریز استوانه‌ای و دریچه استوانه‌ای مشاهده شده است. همچنین با تبدیل سازه از سرریز- دریچه استوانه‌ای به دریچه استوانه‌ای کاهش سریعی در مقادیر پارامترهای بدون‌بعد نسبت عمق آب بالادست به قطر سازه ( ) و نسبت تفاضل عمق آب بالادست و پایین‌دست به قطر سازه ( ) حاصل شده است،‏ که این روند ناشی از کاهش میزان پس‌زدگی آب و کاهش چشمگیر است. همچنین افزایش قطر سازه موجب کاهش ضریب دبی شده که در این رابطه برازش‌های تجربی برای به کمیت درآوردن رفتار ضریب دبی ارائه شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Experimental investigation on cylindrical weir- gate location in perpendicular orientation to flow direction on discharge coefficient

نویسندگان [English]

  • Armaghan Severi
  • Mohsen Masoudian
  • klaus Roettcher
  • Esmaeil Kordi
چکیده [English]

Cylindrical weirs- gates are one of the combined structure types which have advantages such as low cost, simple design, easy construction and the high discharge coefficient. In this study, the cylindrical weir- gate location in perpendicular orientation to flow direction on discharge coefficient have been investigated experimentally. The experiments were conducted in a flume with the length of 7.5 m and width of 40 cm, using the cylindrical models were made up of plastic pipes with diameters of 50, 75, 110 and 125 mm. Experiments were conducted with different gate opening heights from 0 to 60 mm (reaching to the cylindrical gate by considering the available diameter and discharge). The results show that the maximum and the minimum discharge coefficient has been observed in the cylindrical weir and cylindrical gate, respectively. Moreover, by substituting the cylindrical weir- gate with cylindrical gate, the curves depicted amount of against the ratio of upstream flow depth to the cylinder diameter ( ) and the ratio of difference between upstream and downstream flow depth to the cylinder diameter ( ) has reduced suddenly, which this progress was due to decreasing the amount of backwater and remarkable decreasing in upstream depth. Furthermore, increasing in amount of cylindrical structure diameter leads to decrease in discharge coefficient. The best correlated relations for quantifying the behavior of discharge coefficient , were proposed.
Cylindrical weirs- gates are one of the combined structure types which have advantages such as low cost, simple design, easy construction and the high discharge coefficient. In this study, the cylindrical weir- gate location in perpendicular orientation to flow direction on discharge coefficient have been investigated experimentally. The experiments were conducted in a flume with the length of 7.5 m and width of 40 cm, using the cylindrical models were made up of plastic pipes with diameters of 50, 75, 110 and 125 mm. Experiments were conducted with different gate opening heights from 0 to 60 mm (reaching to the cylindrical gate by considering the available diameter and discharge). The results show that the maximum and the minimum discharge coefficient has been observed in the cylindrical weir and cylindrical gate, respectively. Moreover, by substituting the cylindrical weir- gate with cylindrical gate, the curves depicted amount of against the ratio of upstream flow depth to the cylinder diameter ( ) and the ratio of difference between upstream and downstream flow depth to the cylinder diameter ( ) has reduced suddenly, which this progress was due to decreasing the amount of backwater and remarkable decreasing in upstream depth. Furthermore, increasing in amount of cylindrical structure diameter leads to decrease in discharge coefficient. The best correlated relations for quantifying the behavior of discharge coefficient , were proposed.
Cylindrical weirs- gates are one of the combined structure types which have advantages such as low cost, simple design, easy construction and the high discharge coefficient. In this study, the cylindrical weir- gate location in perpendicular orientation to flow direction on discharge coefficient have been investigated experimentally. The experiments were conducted in a flume with the length of 7.5 m and width of 40 cm, using the cylindrical models were made up of plastic pipes with diameters of 50, 75, 110 and 125 mm. Experiments were conducted with different gate opening heights from 0 to 60 mm (reaching to the cylindrical gate by considering the available diameter and discharge). The results show that the maximum and the minimum discharge coefficient has been observed in the cylindrical weir and cylindrical gate, respectively. Moreover, by substituting the cylindrical weir- gate with cylindrical gate, the curves depicted amount of against the ratio of upstream flow depth to the cylinder diameter ( ) and the ratio of difference between upstream and downstream flow depth to the cylinder diameter ( ) has reduced suddenly, which this progress was due to decreasing the amount of backwater and remarkable decreasing in upstream depth. Furthermore, increasing in amount of cylindrical structure diameter leads to decrease in discharge coefficient. The best correlated relations for quantifying the behavior of discharge coefficient , were proposed.
Cylindrical weirs- gates are one of the combined structure types which have advantages such as low cost, simple design, easy construction and the high discharge coefficient. In this study, the cylindrical weir- gate location in perpendicular orientation to flow direction on discharge coefficient have been investigated experimentally. The experiments were conducted in a flume with the length of 7.5 m and width of 40 cm, using the cylindrical models were made up of plastic pipes with diameters of 50, 75, 110 and 125 mm. Experiments were conducted with different gate opening heights from 0 to 60 mm (reaching to the cylindrical gate by considering the available diameter and discharge). The results show that the maximum and the minimum discharge coefficient has been observed in the cylindrical weir and cylindrical gate, respectively. Moreover, by substituting the cylindrical weir- gate with cylindrical gate, the curves depicted amount of against the ratio of upstream flow depth to the cylinder diameter ( ) and the ratio of difference between upstream and downstream flow depth to the cylinder diameter ( ) has reduced suddenly, which this progress was due to decreasing the amount of backwater and remarkable decreasing in upstream depth. Furthermore, increasing in amount of cylindrical structure diameter leads to decrease in discharge coefficient. The best correlated relations for quantifying the behavior of discharge coefficient , were proposed.

کلیدواژه‌ها [English]

  • Simultaneous flow.-Cylindrical gate-Discharge coefficient-Cylindrical weir- gate-Cylindrical weir-