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
1
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
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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