تأثیر آرایش مختلف آبشکن ها بر تغییرات عمق آب در شرایط جریان متغیّر تدریجی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی آبیاری و آبادانی، دانشکده مهندسی و فناوری کشاورزی،دانشگاه تهران، کرج ایران

2 استاد، گروه مهندسی آبیاری و آبادانی دانشکده مهندسی و فناوری کشاورزی

چکیده

آبشکن­ها برای تأمین اهداف گوناگون در رودخانه احداث می‌شوند و پژوهش‌های صورت گرفته بر بررسی عملکردشان در تأمین اهداف مورد نظر متمرکز می‌شوند. در حالی که احداث آبشکن‌ها در آبراهه‌ها بر شرایط هیدرولیکی جریان از جمله عمق یا تراز سطح آب بالادست تأثیر جدی دارند و این موضوع همچنان نیازمند مطالعه است. در این پژوهش که با هدف بررسی نقش آبشکن بر تغییرات تراز سطح آب صورت گرفت، تعداد 18 آرایش مختلف از آبشکن­ها در دامنه دبی 12 تا 70 لیتر بر ثانیه و با ثبت عمق آب در طول و عرض کانال آزمون شد. آرایش آبشکن­ها شامل هشت آرایش یکطرفه و ده آرایش دو طرفه متقارن و نامتقارن است. نتایج بیانگر افزایش عمق آب در بالادست و کاهش آن در طول مشخصی از پایین­دست میدان آبشکن­ها است. از آنجا که افزایش عمق یا تراز سطح آب بالادست سازه به نیروی کششی مربوط است، یک معادله غیر خطی برای برآورد ضریب این نیرو برای آبشکن منفرد ارائه شد. همچنین داده‌ها نشان داد که در همه آرایش­ها نرخ افزایش عمق آب بالادست، با افزایش دبی زیاد شده است. در حالی که طول تأثیر بر نیم‌رخ سطح آب پایین­دست آبشکن­ها در آرایش دو طرفه تابع دبی است؛ اما در آرایش یکطرفه مستقل از آن است. همچنین تأثیر آرایش آبشکن‌ها و شرایط جریان بر پروفیل عرضی سطح آب در عرض فلوم ارائه شده است.

کلیدواژه‌ها

عنوان مقاله [English]

Effect of Various Spur Dikes Arrangement on Water Depth Changes in Gradually Varied Flow Condition

نویسندگان [English]

  • shabnam moghispour 1
  • Salah Kouchakzadeh 2
1 Irrigation and Reclamation Engineering Department, Faculty of Agriculture Engineering and Technology, Tehran Universitiy, Karaj, Iran
2 Prof. Irrigation and Reclamation Engineering Dept. Faculty of Agriculture Engineering and Technology
چکیده [English]

River spur dikes are constructed for achieving different goals and researches are concentrated on investigation of their performances regarding the desired goals. While they show drastic impact on the flow hydraulic conditions in waterways including water surface elevation which still need further investigation and should be treated seriously. The objective of this study was to investigate the effect of spur dikes on water surface elevation variation. For this purpose, 18 different arrangements of spur dikes installation were experimentally studied. The tests were run for seven discharges in the range of 12 to 70 liters per second and by measuring and recording the longitudinal and transverse water depth along the channel. The spur dikes arrangement consists of eight unilateral arrangements and ten two-way symmetrical and asymmetrical arrangements. The results indicated that the water level increased in the upstream while it decreased at the downstream down to a specific length. The increment of the upstream water level was associated to the exerted drag force on the spur dike; accordingly, a nonlinear equation was proposed to estimate the drag coefficient of the single spur dike. The data also showed that the rate of upstream water level increment has increased by increasing flow discharge for all arrangements, while the length of the downstream, which is affected by the spur dikes, in two-way arrangement is depended on discharge while it is independed in one-way arrangement. The effect of spur dikes arrangement and flow conditions on the transverse water level has also been presented.

کلیدواژه‌ها [English]

  • Affected length
  • Backwater
  • Drag force
  • River training
  • Transverse Structure

مراجع

Azinfar, H. & Kells, J. A. (2007). Backwater effect due to a single spur dike. Canadian Journal of Civil Engineering, 34(1), 107–115.
Azinfar, H, & Kells, J. A. (2009). Flow resistance due to a single spur dike in an open channel. Journal of Hydraulic Research, 47(6), 755–763.
Azinfar, H, & Kells, J. A. (2011). Drag force and associated backwater effect due to an open channel spur dike field. Journal of Hydraulic Research, 49(2), 248–256.
Beiz, J. U., Busch, N., Engel, H., & Gasber, G. (2001). Comparison of river training measures in the Rhine - Catchment and their effects on flood behaviour. Proceedings of the Institution of Civil Engineers: Water and Maritime Engineering, 148(3), 123–132.
Busari, A. O., & Li, C. W. (2016). Bulk drag of a regular array of emergent blade-type vegetation stems under gradually varied flow. Journal of Hydro-Environment Research, 12, 59–69.
Cheng, N.-S., & Nguyen, H. T. (2011). Hydraulic Radius for Evaluating Resistance Induced by Simulated Emergent Vegetation in Open-Channel Flows. Journal of Hydraulic Engineering, 137(9), 995–1004.
Criss, R. E., & Shock, E. L. (2001). Flood enhancement through flood control. Geology, 29(10), 875–878.
Huthoff, F., Pinter, N., & Remo, J. W. F. (2013). Theoretical analysis of wing dike impact on river flood stages. Journal of Hydraulic Engineering, 139(5), 550–556.
Im, D., & Kang, H. (2011). Two-dimensional physical habitat modeling of effects of habitat structures on urban stream restoration. Water Science and Engineering, 4(4), 386–395.
Kuhnle, R. A., Jia, Y., & Alonso, C. V. (2008). Measured and simulated flow near a submerged spur dike. Journal of Hydraulic Engineering, 134(7), 916–924.
Ma, B., Dong, F., Peng, W. Q., Liu, X. B., Huang, A. P., Zhang, X. H., & Liu, J. Z. (2020). Evaluation of impact of spur dike designs on enhancement of aquatic habitats in urban streams using 2D habitat numerical simulations. Global Ecology and Conservation, 24, 1–12.
Martino, R., Paterson, A., & Piva, M. (2014). Water level rise upstream a permeable barrier in subcritical flow: Experiment and modeling. Journal of Fluids Engineering, Transactions of the ASME, 136(4), 1–9.
Meile, T., Boillat, J.-L., & Schleiss, A. J. (2011). Flow resistance caused by large-scale bank roughness in a channel. Journal of Hydraulic Engineering, 137(12), 1588–1597.
Möws, R., & Koll, K. (2019). Roughness effect of submerged groyne fields with varying length, groyne distance, and groyne types. Water, 11(6), 1253.
Munson, B.R., Young, D.F., Okishi, T. H. (2002). Fundamentals of fluid mechanics (4th ed.). John Wiley & Sons, Inc.
Muto, Y., Baba, Y., & Aya, S. (2002). Velocity measurements in open channel flow with rectangular embayments formed by spur dykes. Disaster Prevention Research Institute Annuals, Kyoto University, 45, 449–457.
Ohmoto, T., Hirakawa, R., & Koreeda, N. (2002). Effects of water surface oscillation on turbulent flow in an open channel with a series of spur dikes. Hydraulic Measurements and Experimental Methods, 14, 1–10.
Pandey, M., Ahmad, Z., & Sharma, P. K. (2018). Scour around impermeable spur dikes: a review. ISH Journal of Hydraulic Engineering, 24(1), 25–44.
Pinter, N., Thomas, R., & Wlosinski, J. H. (2001). Assessing flood hazard on dynamic rivers. Eos, 82(31).
Tanino, Y., & Nepf, H. M. (2008). Laboratory investigation of mean drag in a random array of rigid, emergent cylinders. Journal of Hydraulic Engineering, 134(1), 34–41.
United States Government Accountability Office (GAO). (2011). Mississippi River : Actions Are Needed to Help Resolve Environmental and Flooding Concerns about the Use of River Training Structures. GAO-12-41(December), 59.
White, F. M. (2016). Fluid mechanics (8th ed.). McGraw-Hill Education.
Wu, B., Wang, G., Ma, J., & Zhang, R. (2005). Case Study: River training and its effects on fluvial Processes in the Lower Yellow River, China. Journal of Hydraulic Engineering, 131(2), 85–96.
Yossef, M. (2002). The effect of groynes on rivers: Literature review. Delft Cluster Publicatienummer 03.03. 04
تحقیقات آب و خاک ایران
دوره 52، شماره 8
آبان 1400
صفحه 2001-2017

فایل ها

هم رسانی

ارجاع به این مقاله

آمار