ارزیابی ویژگی‌های پرش هیدرولیکی در حوضچه‌های آرامش با بستر دندانه‌ای همراه با شیب معکوس

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی سابق کارشناسی ارشد بخش مهندسی آب، دانشگاه شیراز

2 دانشیار گروه مهندسی آب، دانشگاه شیراز

چکیده

حوضچه‌های آرامش از متداول‌ترین سازه‌های کاهنده انرژی می‌باشند که جهت استهلاک انرژی آب درسرعت‌های فوق بحرانی در پایین‌دست سازه‌های آبی نظیر سد‌ها و تنداب‌ها و نیز در شبکه‌های آبیاری و زهکشی استفاده می‌شوند. در این پژوهش به‌منظور بررسی توأم شیب کف معکوس و زبری کنگره‌ای شکل، آزمایش‌هایی با دامنه اعداد فرود در محدوده 4/4 تا 39/7 و شیب منفی صفر تا 02/0- در چهار زبری کنگر‌ه‌ای انجام گردید. نتایج نشان می‌دهد که در شرایط فوق به­طور میانگین 35 و 49 درصد در نسبت اعماق مزدوج و طول نسبی پرش کاهش ایجاد شده است و همچنین اجرای این روش موجب افزایش 21 و 14 درصدی در افت نسبی انرژی و ضریب تنش برشی بستر گردیده است که
می‌تواند موجب کاهش هزینه‌های اجرایی گردد.

کلیدواژه‌ها


عنوان مقاله [English]

Assessment of Hydraulic Jump Characteristics in Stilling Basins with Indented Bed and Adverse Slope

نویسندگان [English]

  • A Ahmadi 1
  • T Honar 2
1 Former MS.c. Student, Water Eng. Department, Shiraz University, Iran
2 Assoc.Prof., Water Eng. Department, Shiraz University, Iran
چکیده [English]

Stilling basins are the most common energy dissipator structures for depreciation of water energy at super critical speeds, typically are used at down stream of hydraulic structures such as dams and chutes and also in structures of irrigation and drainage networks. A new method using a stilling basin with indented bed and adverse slope, is proposed in this research. The experiments were carried out for upstream Froude numbers in the range of 4.4 to 7.39, with four adverse slopes in the range of zero to -0.02, and also four indented roughness values in the laboratory. The results showed the average decreases of 35 and 49 percent on sequential depths and the relative length of a hydraulic jump, also the average increases of 21 and 14 percent on energy loss and coefficient of bed shear stress of hydraulic jump, respectively, which could reduce the administrative costs of stilling basins.

کلیدواژه‌ها [English]

  • Adverse slope
  • Hydraulic jump
  • Indented bed
  • Stilling basin
  • Supercritical flow
 
Abaspour A, Hosseinzadeh A, Farsadizadeh D and Sadraddini AA, 2009. Effect of sinusoidal corrugated bed on hydraulic jump characteristics. Hydro-environment Research 3(2):109-117.
Berami MK and Chamani R, 2006. Hydraulic jump in sloping channel: sequent depth ratio. Journal of Hydraulic Engineering 132(10):1061-1068.
Carollo FG and Ferro V, 2007. Hydraulic jumps on rough beds. Journal of Hydraulic Engineering, ASCE 133: 989-999.
Chow VT, 1964. Open Channel Hydraulics, New York, McGraw-Hill Book Co. NY. Inc. 680 p.
Demetriou JD, 2010. A mechanical energy losses comparison in inclined hydraulic jump over a thin wall and a step. Journal of Hydrodynamic 22: 687-691.
Ead SA and Rajaratnam N, 2002. Hydraulic jumps on corrugated bed. Journal of Hydraulic Engineering ASCE 128: 656-663.
Elsebaie IH and Shabayek SH, 2010. Formation of hydraulic jumps on corrugated beds. Civil and Enviromental Engineering 10: 40-50.
Hager WH, 1992. Energy Dissipators and Hydraulic Jump. Kluwer Academic Publishers. 288 p.
Khaddar, MHA and Rajagopal S, 1972. Hydraulic jump in adverse channel slopes. Irrigation and Power 29: 77-82.
Kindsvater CE, 1944. The hydraulic jump in sloping channel transactions. Journal of Hydraulic Engineering ASCE 109:1107-1120.
Mccorquodale JA, 1994. Hydraulic jump on adverse slope. Journal of Hydraulic Research
32:119-130.
Mohamed Ali HS, 1991. Effect of roughened-bed stilling basin on length of rectangular hydraulic jump. Journal of Hydraulic Engineering ASCE 117: 83-93.
Pagliara S, 2000. Limiting and sill-controlled adverse-slope hydraulic jump. Journal of Hydraulic Engineering ASCE 126: 847-851.
Pagliara S and Lotti L, 2008. Hydraulic jump on rough bed of stream rehabilitation structures. Journal of Hydro- enviroment Research 2:29-38.
Rajaratnam N, 1967. Hydraulic Jumps, Advances in Hydro Science, Academic Press, New York 4:197-280.
Rajaratnam N, 1968. Hydraulic jump on rough bed. Transit Engineering Institution Canada 11:1-8.
Rand W, 1967. Flow over a dentaited sill in an open channel. Journal of Hydraulic Division, American Society of Civil Engineers9: 135-153.
Saneie M, 1991. Hydraulic jump in adverse basin slopes. M. Sc. Thesis, University of Tehran. 203 pp.