Numerical Study of Flow on Stepped Spillway and Its Comparison with Experimental Results

Document Type : Research Paper

Authors

Abstract

Stepped spillways are frequently used in the structure of dams, river engineering and soil conservation. Energy dissipation on this structure due to the presence of several steps is high, so causes reduction in construction costs of stilling basin. On the other hand, nowadays numerical models are new methods for flow analysis. The purpose of this study was numerical investigation of the flow on the stepped spillway and calculation of the energy loss caused by it. Also, the fluctuations of velocity vectors, shear stress and pressure during the flow on the each step were compared. For this purpose, a physical model of the stepped spillway was built with a slope ratio of 2:1 (horizontal: vertical), and the experiments were performed with 10 different flow rates. The numerical simulations also performed under the same conditions by using FLUENT software and RNG k-ε turbulence model. Finally, the results of the numerical model were compared with experimental data. The results indicated that the numerical model with an error of about 3% had a good agreement with the physical model, so it could be trusted for anticipating complex rotational flows on the stepped spillways.  

Keywords

Main Subjects


منابع مورداستفاده
سلماسی ف، 1388. گزارش نهایی طرح تحقیقاتی استهلاک انرژی در سرریزهای پلکانی گابیونی. دانشگاه تبریز، دانشکده کشاورزی.
معصومی اصفهانی ح­ر، 1385. مطالعه ترکیبی عوامل مؤثر بر افت انرژی در سرریزهای پلکانی. پایان­نامه کارشناسی ارشد، دانشکده عمران و محیط زیست، دانشگاه صنعتی امیر کبیر.
Anonymous, 2005. Fluent 6.2 User's Guide.
 
Cassidy JJ, 1965. Rotational flow over spillway of finite height. Journal of Hydraulic Engineering ASCE 91(6):       155-173.
Chamani MR and Rajaratnam N, 1994. Jet flow on stepped spillways. Journal of Hydraulic Engineering ASCE 121(2): 254-259.
Chanson H, 2001. Hydraulic design of stepped spillway and downstream energy dissipaters. Dam Engineering 11)4(: 205-242.
Chen Q, Dai G and Liu H, 2002. Volume of fluid model for turbulent numerical simulation of stepped spillway overflow. Journal of Hydraulic Engineering ASCE 128(70): 683-688.
Launder BE and Spalding DB, 1972. Lectures in Mathematical Model of Turbulent. Academic Press, Landon.
Musavi Jahromi H, Bina M and Salmasi F, 2008. Physical and numerical modeling of the nappe flow in the stepped spillway. Journal of Applied Science 8(9): 1720-1725.
Mansoori A, Hamedi AM, 2011. Scrutinization of energy loss in stepped spillway equipped with inclined steps together with end sill by FLUENT numerical models. World Renewable Energy Congress, Linkoping, Sweden, 8-11 May, 2011.
Sorensen RM, 1985. Stepped spillway hydraulic model investigation. Journal of Hydraulic Engineering ASCE 111(12): 1461-1472.
Tabbara M, Chatila J and Awwad R, 2005. Computational simulation of flow over steeped spillway. Journal of Computer and Structures 83: 2215-2224.