توسعه مدل عددی جریان غیرماندگار همراه با انتقال رسوب در سیستم‌های رودخانه‌ای

نویسندگان

1 دانش اموخته دکتری سازه های آبی دانشگاه رازی

2 دانشگاه رازی

3 دانشگاه شهید چمران اهواز

چکیده

برای مهندسان بسیار ضروری و مهم است، که از چگونگی روندیابی جریان و انتقال رسوب آگاهی داشته باشند. مدل‌های ریاضی ابزار با ارزشی را برای پیش‌بینی شرایط جریان و فرایند انتقال رسوب فراهم نموده‌اند و به‌نحو گسترده‌ای در مدیریت و مهندسی آب کاربرد دارند. هدف اصلی این تحقیق، توسعه مدل عددی هیدرودینامیکی یک بعدی و غیرماندگار است، که برای روندیابی جریان و انتقال رسوب به‌صورت شبه‌کوپل در سیستم‌های رودخانه‌ای ‌مورد استفاده قرار می‌گیرد. در این تحقیق، ابتدا مدلی ریاضی توسعه داده شده است، که در آن معادلات سنت ونانت در سیستم‌های رودخانه‌ایی حل می-شوند. این معادلات پس از خطی شدن به روش تفاضل‌های محدود، به‌صورت نیمه ضمنی و از طریق تکنیک زیگزاگی حل می‌شوند. پس از حل معادلات و محاسبه خصوصیات هیدرولیک جریان در رودخانه، این مشخصات برای حل معادلات انتقال رسوب استفاده می‌شوند. از معادله دینامیکی انتقال- پخش و معادله دیفرانسیلی بار بستر به‌ترتیب برای محاسبه میزان انتقال بار معلق و بار بستر استفاده می‌شود. بعد از محاسبه میزان انتقال رسوب، از معادله اکسنر برای محاسبه تغییرات ارتفاع بستر در رودخانه استفاده می‌شود. در نهایت در این تحقیق مدل عددی با مدل هیدرولیکی Hec-Ras مورد مقایسه قرار گرفت که نتایج، دقت بالای مدل عددی را نشان می دهد.

کلیدواژه‌ها


عنوان مقاله [English]

Developing Unsteady Flow Numerical Model Semi-Coupled with Sediment Transport in River Systems

نویسندگان [English]

  • Sabah Mohamadi 1
  • Rasool Ghobadian 2
  • mahmood kashefipour 3
1 Phd graduate of razi university
2 associate professor
3 professor
چکیده [English]

It is so essential for engineers to be able to predict the places in which deposition and scouring occurs. Numerical models are valuable tools for estimating flow conditions and sediment transport, and are widely applied in water resources management. The main goal of this study is to develop one dimensional, unsteady, hydrodynamic model which can be used for simulating flow and sediment transport as semi-coupled model in river systems. In this research, the Saint- Venant’s equations are numerically solved for river systems. In this research a semi implicit finite difference scheme is developed to solve the Saint- Venant equations for unsteady flow. The linear equations are produced based on the partial differential equations and the staggered technique. After solving the above equations, the computed hydraulic parameters in this part are sent to the sediment transport segment. . The dynamic advection- dispersion equation and the sediment continuity partial differential equation were applied to calculate the suspended sediment concentration and bed load transport, respectively. The Exner equation is then used to predict the changes in the river bed elevations. Finally, the model was compared to the Hec-Ras Model and the results showed that the developed model has good accuracy.
Keywords: Sediment Transport, Flow Routing, River Systems, Numerical Model

کلیدواژه‌ها [English]

  • sediment transport
  • numerical model
  • flow routing
  • river system
  • river
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