Numerical simulation of free flow over Gabion crump weirs

Subject Areas : Irrigation and Drainage

محمد توکل صدرآبادی ¹ ( فارق التحصیل کارشناسی ارشد عمران آب و سازه هیدرولیک-دانشکده علوم اب-دانشگاه شهید چمران اهواز )
منوچر فتحی مقدم ² ( گروه سازه های آبی، دانشگاه شهید چمران اهواز، اهواز، ایران. )
رضا محمدپور ³ ( واحد استهبان، دانشگاه آزاد اسلامی، استهبان، ایران. )

Received: 2016-06-19 Accepted : 2016-10-10 Published : 2016-06-01

Keywords: discharge coefficient, Numerical simulation, ضریب دبی, gabion crump weirs, through flow discharge, تفکیک جریان روگذر و درون‌گذر, سرریز گابیونی کرامپ و شبیه‌سازی عددی,

Abstract :

Environmentally friendly nature and the direct impact of gabion weirs on the quality parameters of rivers as well as simple design and construction of such structures, has putted them under consideration in the recent years. In this research, Hydraulic parameters of gabion crump weirs including water surface profile, discharge coefficient and through flow discharge are investigated numerically in free flow condition using flow-3d software. A total number of 18 models comprising 6 different geometries studied in 3 different porosities of 43%,44% an 46%. Results indicate that increasing the average diameter of particles (d50) leads to the increase of through flow discharge in addition to discharge coefficient and friction loss. Also increasing the side slopes of weirs, decreases the discharge coefficient and through flow discharge. In addition, it is shown that the downstream slope has a slightly larger effect on discharge coefficient where upstream slope’s effect on through flow discharge is higher. Finally, using multivariate non-linear regression analysis, experimental equations were developed in order to estimate the discharge coefficient and the through flow discharge.

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