شبیه سازی و بهینه سازی پارامترهای هیدرولیکی جریان آشفته در تخلیه کننده های تحتانی سد با استفاده از Open FOAM

فصلنامه علمی مهندسی منابع آب

مقاله 4، دوره 17، شماره 60، اردیبهشت 1403، صفحه 53-71   

نوع مقاله: مقاله پژوهشی

شناسه دیجیتال (DOI): 10.30495/wej.2024.31570.2379

نویسندگان

مهدی قبادی¹؛ سینا فرد مرادی نیا^{* 2}

¹دانش آموخته کارشناسی ارشد مهندسی عمران-آب و سازه‌های هیدرولیکی،گروه مهندسی عمران، واحد تبریز، دانشگاه آزاد اسلامی، تبریز، ایران

²گروه مهندسی عمران، واحد تبریز، دانشگاه آزاد اسلامی، تبریز، ایران/ مرکز تحقیقات رباتیک و فناوری‌های نرم، واحد تبریز ، دانشگاه آزاد اسلامی، تبریز، ایران

تاریخ دریافت: 25 بهمن 1401،  تاریخ بازنگری: 17 اردیبهشت 1402،  تاریخ پذیرش: 25 بهمن 1402 

چکیده

استفاده از روش های عددی به طور گسترده در تشخیص عملکرد سیستم های هیدرولیکی و بهینه سازی آنها مورد استفاده قرار می گیرد. مدل سازی عددی هزینه کمتری نسبت به کار تجربی دارد. روش های عددی می توانند برای بررسی صحت نتایح و مقایسه بین آنها نیز مورد بهره برداری قرار بگیرند. در این پایان نامه روش حجم سیال برای شبیه سازی جریان سطح آزاد آب در داخل تخلیه کننده تحتانی سد کانی رش مورد استفاده قرار گرفته است. از آنحاییکه جریان در داخل تخلیه کننده ها به صورت آشفته است، از مدل های توربولانسی k-ε ، k-ε RNG ، k-ω SST ، k-ω و همچنین LES استفاده و مقایسه شده اند. همچنین ضریب تخلیه در داخل تخلیه کننده تحتانی و دبی هوادهی نیز مورد بررسی و مقایسه قرار گرفته است. نتایج بیانگر این مطلب است که روش عددی استفاده شده در اپن فوم، با کارهای تجربی تطابقت بسیار خوبی دارد، مخصوصاَ در مدل توربولانسی k-ω نسبت به k-ε. نتایج بیانگر این مطلب بود که در درصد خطا شبیه سازی برای ضریب تخلیه چیزی در حدود ۷ درصد می باشد و نتایج بهینه و شبیه سازی برای دبی هوادهی نیز به ترتیب برابر مقدار 20 و 24 متر مکعب بر ساعت است. همچنین مشخص گردید که با افزایش قطر هیدرولیکی، ضریب تخلیه افزایش می یابد و با افزایش طول تخلیه کننده تحتانی، ضریب تخلیه دچار کاهش می شود. انتخاب بهینه طول تخلیه کننده تحتانی وابسته به ارتفاع پشت سد می باشد.

کلیدواژه‌ها

تخلیه کننده تحتانی سد؛ Open FOAM؛ دینامیک سیالات محاسباتی؛ اگوریتم ژنتیک؛ ضریب تخلیه

عنوان مقاله [English]

Simulation and Optimization of Hydraulics parameter in Turbulence Flow of Dam Bottom Outlet Using OpenFOAM

نویسندگان [English]

Mehdi Ghobadi¹؛ Sina Fard Moradinia²

¹Master's Degree in Civil Engineering - Water and Hydraulic Structures, Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran

²Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran/ Robotics and Soft Technologies Research Center, Tabriz Branch, Islamic Azad University, Tabriz, Iran

چکیده [English]

Abstract
Introduction: The use of numerical methods is widely used in diagnosing the performance of hydraulic systems and optimizing them. Numerical modeling is less expensive than experimental work. Numerical methods can be used to check the accuracy of the results and compare them. In this thesis, the fluid volume method is used to simulate the free surface flow of water inside the lower discharger of Kani Sib Dam. Since the flow inside the dischargers is turbulent, k-ε, k-ε RNG, k-ω SST, k-ω and also LES turbulence models have been used and compared. Also, the discharge coefficient inside the lower discharger and the aeration flow have been investigated and compared.
Methods: To simulate the turbulent flow inside the lower discharger, continuity equations, momentum, energy and equation of state along with equations related to the aforementioned turbulence models have been solved using OpenFoam software.  The set of equations of conservation of mass, conservation of momentum and energy for turbulent flow, which are so-called Reynolds averaging equations, are the governing equations of the flow and are used to model the flow by solving them numerically.
Findings: The simulation and optimization of the hydraulic parameters of the turbulent flow in the lower dischargers of the Sib Mineral Dam has been completed using OpenFOAM. The results have been made on the parameters of the lower discharger of Sib mineral dam. And the optimization is done using genetic algorithm. In this research, it was found that with the increase of the hydraulic diameter, the discharge coefficient increases. Also, with the increase of the hydraulic diameter, the core of the water fluid jet inside the discharger undergoes a strong fluctuation, which can increase the shear stress. An excessive increase in shear stress can cause corrosion of the discharge walls. On the other hand, with a further decrease in shear stress, deposition inside the lower discharger increases. At the same time, with the increase in the length of the lower discharger, the discharge coefficient decreases. The optimal selection of the length of the lower drain depends on the height behind the dam. As the opening rate increases, the discharge coefficient also increases and the k- ε turbulence model gives more acceptable results to estimate the results. Finally, for each aeration flow rate, a set of optimal values for the discharge coefficient and the opening rate has been obtained.

کلیدواژه‌ها [English]

Dam bottom outlet, OpenFOAM, CFD, Genetic Alghorithm, Discharge coefficient

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