Development of a computer model for long-throated flumes based on manning equation and different side slopes of trapezoidal channels

Document Type: Full Article

Authors

1 Department of Water Engineering, College of Agricultural, Jahrom University, Jahrom, I. R. Iran

2 Department of Water Engineering, College of Agricultural, Shiraz University, Shiraz I. R. Iran

Abstract

ABSTRACT- Measurement of irrigation water in agricultural areas is necessary, especially, in arid and semi-arid regions. Long-throated flumes have been used to measure irrigation water and are known to be inexpensive devices with high performances. In these structures, head-discharge tables are predicted theoretically with no need to calibrate. In this study, the model of LOTF (LOng Throated Flumes) was developed in VB. net programming language, in which, friction head loss and h-Q (h is head at measuring station and Q is discharge) tables were predicted by using the Manning's equation. The predicted tables of h-Q by the LOTF model were perfectly similar to the results of Win Flume and HEC-RAS model which are universally used for these flumes and open channel flow, respectively. Calculated h-Q tables in trapezoidal flumes with two different side slopes of 0 and 1, 0 and 2, and 0 and 4 were computed by the LOTF and HEC-RAS models and were the same as those predicted by the WinFlume model with equal average of these side slopes of channel. At a water depth, in trapezoidal sections with different and equal average side slopes, the resulted h-Q tables in the three models were the same.

Keywords


Article Title [Persian]

ارائه یک مدل کامپیوتری برای طراحی فلوم های گلوبلند در کانال های ذوزنقه ای با دیواره های با شیب متفاوت بر اساس معادله مانینگ

Authors [Persian]

  • مهدی مهبد 1
  • شاهرخ زندپارسا 2
1 گروه علوم و مهندسی آب، دانشکده کشاورزی، دانشگاه جهرم، جهرم، ج. ا. ایران
2 گروه مهندسی آب، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ج. ا. ایران
Abstract [Persian]

چکیده-با توجه به کمبود منابع آب در مناطق خشک و نیمه خشک، اندازه گیری دقیق مقدار جریان جهت توزیع مناسب و عادلانه آب از اهمیت ویژه ای برخوردار می باشد. برای این منظور فلوم های گلو بلند، با توجه به اینکه تهیه منحنی دبی-اشل نیاز به واسنجی ندارد به عنوان یک ابزار کم هزینه و البته با کارکرد دقیق مطرح می باشند. در این مطالعه مدلی با نام LOTF (LOng Throated Flumes)  جهت تهیه جدول دبی-اشل برای فلوم های گلو بلند با استفاده از معادله مانینگ در شرایطی که شیب دیواره های کانال یکسان نباشند، ارائه گردید. نتایج نشان داد که جدول دبی اشل تولید شده توسط مدل LOTF با نتایج مدل های HEC-RAS و WinFlume که برای ترسیم نیمرخ سطح آب به ترتیب در کانال های باز و فلوم های گلوبلند استفاده می گردند، تطابق کاملی داشت. همچنین در شرایطی که دیواره های کانال دارای شیب متفاوت برابر با (0و2) و (0و4) داشتند، منحنی دبی اشل مدل LOTF با منحنی حاصل از دو مدل دیگر در شرایطی که شیب دیواره برابر با مقدار میانگین شیب دو طرف کانال باشد مقایسه گردید و نتایج نشان داد که می توان از میانگین شیب دیواره ها به عنوان شیب دیواره کانال در مدل WinFlume استفاده نمود.

Keywords [Persian]

  • واژه‏های کلیدی:
  • فلوم های گلوبلند
  • معادله مانینگ
  • مدل WinFlume
  • مدل LOTF
  • جدول دبی اشل
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