مدل‏ سازی جریان در یک قوس از رودخانۀ طبیعی بر اساس مدل‏ های مختلف آشفتگی (مطالعۀ موردی: رودخانۀ دوآب صمصامی)

نوع مقاله : پژوهشی

نویسندگان

1 دانشیار گروه مرتع و آبخیزداری، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه شهرکرد‌

2 دانشجوی دکتری تخصصی علوم و مهندسی آبخیزداری، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه شهرکرد‌

3 استادیار گروه مهندسی عمران، دانشکدۀ فنی و مهندسی، دانشگاه شهرکرد‌

4 استاد گروه پترولوژی، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه شهرکرد‌

5 استادیار گروه مرتع و آبخیزداری، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه شهرکرد‌

چکیده

مدل‏سازی جریان در رودخانه‏ها با توجه به مسیر پیچان‏رودی آنها بسیار پیچیده بوده و اغلب مستلزم استفاده از یک مدل عددی قوی برای پیش‏بینی آثار آشفتگی است. همچنین، انتخاب نوع مدل آشفتگی می‌تواند در شبیه‏سازی و بررسی خصوصیات جریان مؤثر ‏باشد. انواع مختلفی از مدل‏های آشفتگی در مدل عددی SSIIM قابل استفاده است که در تحقیق حاضر با هدف بررسی کارایی مدل‏های آشفتگی، از سه نوع مختلف مدل آشفتگی k-Ԑ یعنی نوع استاندارد، بر اساس سرعت آب و RNG به منظور شبیه‏سازی خصوصیات جریان در نقاط مختلف از مقطع عرضی 45 درجه از یک قوس تند واقع در رودخانۀ دوآب صمصامی از سرشاخه‏های کارون بزرگ استفاده شد. با مقایسۀ مقادیر اندازه‌گیری‌شدۀ مؤلفه‏های سرعت، نتایج به‌دست‌آمده از مدل‌ها مشخص شد. مدل k-Ԑ استاندارد در تعیین مؤلفۀ قائم سرعت و نوع مدل k-Ԑ بر اساس سرعت آب برای مؤلفۀ طولی سرعت دقت بیشتری دارد که در مجموع قابلیت کلیۀ مدل‏های آشفتگی یادشده مناسب ارزیابی می‌شود. همچنین، درنظرگرفتن دقیق ناهمواری‏های بستر و زبری کنارۀ‏ کانال رودخانه در مدل عددی می‌تواند بر افزایش صحت نتایج مدل تأثیر بسزایی داشته باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Flow modeling in a bend of a natural river based on different turbulence models(case study:Doab Samsami River)

نویسندگان [English]

  • afshin honarbakhsh 1
  • Rouhollah Karimian kakolaki 2
  • gholamreza shams ghahfarokhi 3
  • alireza davoudian dehkordi 4
  • mehdi pajouhesh 5
1 Associate Professor of range and Watershed Management Faculty of Natural Resources and Earth Sciences, Shahrekord University
2 Ph.D. student of Watershed Science and Engineering Faculty of Natural Resources and Earth Sciences, Shahrekord University, Iran
3 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Shahrekord University.
4 Full Professor, Department of Petrology, Faculty of Natural Resources and Earth Sciences, Shahrekord University.
5 head of rangeland and watershed management group
چکیده [English]

Flow modeling in rivers is very complicated due to their meandering path. Therefore, the use of an accurate numerical model for predicting flow pattern and the effects of flow turbulence is necessary. Furthermore, choosing the type of turbulence model can be effective in simulating and studying flow properties. Different types of turbulence models can be used in SSIIM numerical model. In this study, with the aim of investigating the efficiency of turbulence models, three different kindes of k-Ԑ turbulence model,including the standard type, based on water velocity and RNG, are used to simulate flow characteristics in different points of a 45 degrees cross-section from a steep bend located on the Doab Samsami river. Comparing the measured values of the velocity component with the results of the model indicated that the standard k-Ԑ model for determining the vertical component of velocity and k-Ԑ model based on water velocity for the longitudinal component of the velocity are best models in accuracy, respectively and generally the ability of all mentioned the turbulence models evaluated well. Moreover, exact consideration of bed roughness and roughness of the channel bank in the numerical model can have a significant effect on the accuracy of the model results.

کلیدواژه‌ها [English]

  • k-Ԑ turbulence model
  • SSIIM numerical model
  • Doab Samsami River
  • RNG
[1]. Yousefi, H, Golshan,M , Pirnia, A. Evaluation of HEC-HMS Hydrological Model in estimating Flood Hydrograph of Dry and Humid regions. Journal of Ecohydrology, 2018; 5(1): 319 – 330. .)Persian(.
 
[2]. Yousefi, H, Ehara,S ,Noorollahi, Y. Modifying the analysis made by water quality index using multi-criteria decision making methods. Journal of African Earth sciences, 2018; 138, 309 – 318.
[3]. Yousefi, H, Tavakkoli-Moghaddam, R, Oliaei, MTB, Mohammadi, M. Solving a bi-objective vehicle routing problem under uncertainty by a revised multichoice goal programming approach. International Journal of Industrial Engineering Computations, 2017; 8(3):283-302
[4]. Xiufang Z. Pingyi W. and Y. Chengyu. Experimental study on flow turbulence distribution around a spur dike with different structure. Journal of Procedia Engineering,2015; 28: 772-775.
[5]. Hao, Z. Hajime, N. kenji, K. and B. Yasyuki. Experiment and simulation of turbulent flow in local scour around a spur dyke. Journal of Sediment Research, 2014; 24: 33-45.
[6]. Lai, Y. G. and Greimann, B.P. Predicting contraction scour with two-dimensional depth averaged model. Journal of Hydraulic Research, 2010; 48(3): 383-387.
[7]. Khosravi, G. The numerical simulation of flow and sediment transport with model CCHE2D (Case Study: meander downstream Minab). Master's thesis, University of Hormozgan, Bandarabbas, Iran. 2012. (Persian).
[8]. Fathi, M., A. Honarbakhsh, M. Rostami and D. Davoodian Dehkordi. simulating the flow pattern with a two-dimensional numerical model in a range of natural meanders, Case Study: Khoshkerood Farsan River, Chaharmahal and Bakhtiari, Journal of Science and Technology of Agriculture and Natural Resources, Water and Soil Sciences. 2012; 62(1): 95-108. (Persian).
[9]. Andersson. B, Andersson.R, Hakansson. L, Mortensen. M, Sudiyo. R and vanWachem. B. Computational fluid dynamics for engineers. Cambridge University Press, 2012.
[10].            Rodi, W. and Leschziner M. A. Calculation of Strongly Curved Open Channel Flow. Journal of the Hydraulic Division,1978; 105(HY10) : 1297-1333.
[11].            Shettar, A.S., and Murthy, K.K.A numerical study of division of flow in open channels, Journal of Hydraulic Research, Delft, The Netherlands,1996; 34)5( :651-675.
 
[12].            Han, S.S. Characteristics of flow around 90 open channel bends. PhD. Thesis. Dept. of Building,Civil and Environmental Engineering, Concordia University, Montreal, Quebec.2010.
[13].            Van Balen, W., Uijttewaal, W.S.J., and Blanckaert, K. Large eddy simulation of a mildly curved open channel flow", J. Fluid Mech.2009; 630(1): 413-442.
[14].            SafarzadehGandshamin, A., and Salehi Neishabouri, A. A. Numerical study of turbulent flow pattern and qualitative study of sediment transport and erosion in lateral drainage from the river. Journal of Modarres Technical and Engineering,2007; 25(1) : 1-18.( Persian).
[15].            Omid Beygi, M. A. Laboratory study and numerical simulation of three dimensional flow pattern in lateral drainage of the river in the presence of submerged panels. Msc Thesis. Dept. of Agriculture, Tarbiat Modarres University.2010.( Persian).
[16].            Mozaffari, J., Samadi, A., Mohseni Movahhed, S. A., Davoud-Maghami, D. Comparison of RSM and LES Turbulence Models on Sharp Bend. Journal of Ferdowsi Civil Engineering, 2015; 27(1): 77-86. (Persian).
[17].            Zhang, M. L., and Shen, Y. M. Three-dimensional simulation of meandering river based on 3-D RNG k-ɛ turbulence model. Journal of Hydrodynamics,2008; 20(4) : 448-455.
[18].            Yu, L. R. Flow and transport simulation of Madeira River using three depth-averaged two-equation turbulence closure models. Water Science and Engineering, 2012. 5(1): 11-25
[19].            Wu, W. CCHE2D Sediment Transport Model (Version 2.1). Tech Report No. NCCHETR- 2001-3, NCCHE, University of Mississippi, 2009. USA, P: 12.
[20].            Cea, L., Pena, L., J. Puertas, J., M. E. Vazquez-Cendon, M. E., and Pena, E. Application of several depth-averaged turbulence models to simulate flow in vertical slot fishways. Journal of Hydraulic Engineering, 2007;133(2):160–172.
[21].            Launder, B. E., and Spalding, D. B. The numerical computation of turbulent flows. Computer Methods in Applied Mechanics and Engineering, 1974; 3(2): 269-289.