توسعه روابط مقاومت جریان در رودخانه‌های کوهستانی بر اساس مطالعه آزمایشگاهی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار، گروه مهندسی آب دانشگاه ارومیه

2 دانشجوی کارشناسی ارشد سازه‌های آبی دانشگاه ارومیه

چکیده

هدف این تحقیق ارائه و توسعه روابطی برای محاسبه ضرایب مقاومت جریان در آبراهه­های با بستر سنگریزه­ای می‌باشد. بدین منظور، آزمایش­هایی در یک فلوم با قابلیت شیب­پذیری، با طول 8 متر و عرض 25/0 متر انجام گرفت. چهار شیب مختلف بستر (4، 6، 8 و 10 در هزار)، دو نوع ذرات سنگریزه­ای به شکل تیز گوشه و طبیعی، سه نوع اندازه متوسط ذرات (3/65، 6/46 و 38 میلی­متر) و چهار دبی جریان (01/0، 017/0، 024/0 و 031/0 متر مکعب در ثانیه) به عنوان متغیرهای مورد استفاده تحقیق حاضر بودند. با استفاده از تعریف­های جدید برای متغیرهای بی­بعد در شکل معادله­های بی­بعد هندسه هیدرولیک، روابط مقاومت جریان جدیدی برای ذرات طبیعی و تیز گوشه توسعه داده شد. همچنین روابطی برای ضریب زبری مانینگ در هر دو نوع سنگریزه طبیعی و تیز گوشه ارائه شد. علاوه بر آن نتایج نشان داد که معادله­های توسعه یافته بر اساس پارامترهای بی­بعد هندسه هیدرولیک، بهترین روش برای ارتباط سرعت به دبی جریان در رودخانه­های کوهستانی می­باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Develop of Flow Resistance Equations in Mountain Rivers Based On Experimental Study

نویسندگان [English]

  • Mohmmad Hemati 1
  • Vafa Mostafa 2
چکیده [English]

     The aim of this research is to develop relations to estimate the flow resistance coefficients in gravel-bed channels. In this regards, the experiments were carried out in a tilting flume with length of 8m and width of 0.25m. In this research, four different bed slopes (0.004, 0.006, 0.008 and 0.01), two gravel types (natural and crushed shapes), three mean diameter (d50) of gravels (65.3, 46.6 and 38 mm) and four discharges (0.01, 0.017, 0.024 and .031 m3/s) were used as a variables. New flow resistance equations were developed for natural and crushed gravels by using the new definitions for dimensionless variables in terms of non-dimensional hydraulic geometry equations. Also, new equations were presented to estimate Manning’s roughness coefficient for both shapes.  In addition, the results showed that the developed equations based on non-dimensional hydraulic geometry relations are the best way to link the mean flow velocity to the flow discharge in mountain rivers.

کلیدواژه‌ها [English]

  • hydraulic geometry
  • gravel bed
  • Flow resistance equations
  • Particles shape
  • Mountain rivers
1-  بهرامی یاراحمدی، م. و م. شفاعی بجستان. 1390. بررسی آزمایشگاهی اثر شکل ذرات رسوبی بستر بر ضریب زبری مانینگ. نشریه آب و خاک مشهد (علوم و صنایع کشاورزی)، 25(1): 60-51.
 
2-  Aberle, J., Dittrich, A. and F. Nestmann.1999. Estimation of gravel bed river flow resistance. Journal of Hydraulic Engineering, 125(12):1315–1319.
 
3-  Aberle, J. and G. M.Smart. 2003. The influence of roughness structure on flow resistance on steep slopes. Journal of Hydraulic Research,41: 259–269.
 
4-  Bathurst J.C.1993.Flow resistance through the channel network. In K. BevenandM. J. Kirkby (Eds.),Channel Network Hydrology, Wiley, Chichester, (pp. 6998).
 
5-  Bathurst, J.C., Li, R. H. and D.B. Simons.1981. Resistance equation for large-scale roughness. Journal of Hydraulic Engineering, 107(12):1593–1613.
 
6-  Bayazit, M. 1982. Flow structure and sediment transport mechanics in steep channels. In: Proceedings of 156th Euromech, Mechanics of Sediment Transport, 12-14 Jul., Istanbul, Turkey, pp. 197–206.
 
7-  Bray, D. I. 1979. Estimating average velocity in gravel-bed rivers. Journal of Hydraulic Division, 105(9):1103-1122.
 
8-  Charlton, F., Brown, P. M. and R. W. Benson. 1978. The hydraulic geometry of some gravel rivers in Britain. Report IT 180, Hydraulics Research Station, Wallingford, UK.
 
9-  Comiti, F., Mao, L., Wilcox, A., Wohl, E. and M. Lenzi. 2007. Field derived relationships for flow velocity and resistance in high-gradient streams. Journal of Hydrology, 340:48–62.
 
10- Comiti, F., Cadol, D. and E. Wohl. 2009. Flow regimes, bed morphology and flow resistance in self-formed step-pool channels. Water Resource Research, 45(4):1-18.
 
11- David, G. C. L., Wohl, E. E., Yochum, S. E. and B. P.   Bledsoe. 2010. Controls on spatial variations in flow resistance along steep mountain streams. Water Resource Research, 46(3):1-21.
 
12- Dittrich, A. and K. Koll. 1997. Velocity field and resistance of flow over rough surfaces with large and small submergence. International Journal of Sediment Research, 12(3): 21–33.
 
13- Ferguson, R. 2007. Flow resistance equations for gravel and boulder bed streams. Water Resource Research, 43(5):1–12.
 
14- Habibi, M., Namaee, M. R. and M. Saneie. 2014. An experimental investigation to calculate flow resistance in a steep river. KSCE Journal of Civil Engineering, 18(4):1176-1184.
 
15- Hey, R.D. 1979. Flow resistance in gravel-bed rivers. Journal of Hydraulic Division, 105(4):365–379.
 
16- Jarrett, R. D. 1984. Hydraulics of High Gradient Streams. Journal of Hydraulic Engineering, ASCE, 110 (11): 1519- 1539.
 
17- Kellerhals, R. 1973. Hydraulic performance of mountain streams. In: Proceeding of 15th Congress of the IAHR, Istanbul.1, pp. 467–473.
 
18- Kim, J. S., Lee, C. J., Kim, W. and Y. J. Kim. 2010. Roughness coefficient and its uncertainty in gravel-bed river. Water Science and Engineering, 3(2):217-232.
 
19- Kironoto, B.A. and W.H. Graf. 1994. Turbulence characteristics in rough uniform open-channel flow. In: Proceeding of Institution of Civil Engineers. Water, Maritime and Energy, 106:333–344.
 
20- Lee, A. J. and R. I.  Ferguson. 2002. Velocity and flow resistance in step-pool streams. Geomorphology, 46:59–71.
 
21- Limerinos, J. T. 1970. Determination of the manning coefficient from measured bed roughness in natural channels. U.S. Geology of Survey Water Supply Paper, 1898-B, 47 p.
 
22- Nitsche, M. 2012. Macro-roughness, flow resistance and sediment transport in steep mountain streams. Ph. D. Dissertation, University of Leipzig.
 
23- Prakash, H. 2014. Prediction of flow resistance in gravel bed river. International Journal of Engineering and Technology Research (IJETR), 2(4):155-159.
 
24- Rickenmann, D. 1994. An alternative equation for the mean velocity in gravel-bed rivers and mountain torrents. Journal of Hydraulic Engineering, 94(1): 672-676.
 
25- Rickenmann, D. 1991. Hyper concentrated flow and sediment transport at steep slopes, Journal of Hydraulic Engineering, 117(11): 1419–1439.
 
26- Rickenmann, D. and A. Recking. 2011. Evaluation of flow resistance in gravel-bed rivers through a large field data set.  Water Resources Research, 47(7):1-22.
 
27- Shafai- Bejestan, M. and M. Bahrami-Yarahmadi. 2012. River bed resistance coefficient variation of different sediment particle shapes. World Environmental and Water Resources Congress, May 20-24, Albuquerque, New Mexico, United States, P:1585-1591.
 
28- Soto, U, A. and M. Madrid Aris. 1994. Roughness coefficient in mountain rivers. Journal of Hydraulic Engineering, American Society of Civil Engineering, New York, 1: 1-8.
 
29- Ugarte, A. and M. Madrid-Aris. 1994. Roughness coefficient in mountain rivers. In: Hydraulic Engineering '94, Proceedings of the 1994 Conference, Buffalo, New York, August 1-5, Volume 1.
 
30- Zimmermann, A. 2010. Flow resistance in steep streams: An experimental study. Water Resources Research, 46(9):1-18.
دوره 40، 1-1
ویژه نامه
خرداد 1396
صفحه 13-25
  • تاریخ دریافت: 10 آبان 1394
  • تاریخ بازنگری: 17 خرداد 1396
  • تاریخ پذیرش: 28 آذر 1394
  • تاریخ انتشار: 11 دی 1348