تعیین ضریب پخش طولی با انجام آزمایش‌های ردیابی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری مهندسی منابع آب، دانشگاه تهران

2 دانشیار گروه مهندسی آبیاری و آبادانی، دانشگاه تهران

3 استاد گروه مهندسی آبیاری و آبادانی، دانشگاه تهران

چکیده

تاکنون سه رویکرد شامل آزمایش‌های ردیابی، انتگرال‌گیری از پروفیل سرعت و کاربرد رابطه‌های تجربی به عنوان روش‌های متداول به منظور برآورد ضریب پخش طولی در رودخانه‌ها و انهار به کار رفته است. در مقالة حاضر معادلة جدید ضریب پخش طولی بر مبنای داده‌های برداشت‌شده از آزمایش‌های ردیابی با استفاده از ردیاب نمک و کاربرد دو گروه مختلف از روابط بنیادی تجربی این ضریب تعیین و ارزیابی شده است. برای این منظور طولی معادل 500 متر از کانال بتنی برای اجرای آزمایش‌های ردیابی، در سه طول اختلاط متفاوت برابر با 45، 75 و 100 متر، در بهمن‌ماه 1393 به‌کار برده شد. نتایج نشان می‌دهد که اختلاف بین میانگین، واریانس و غلظت ماکزیمم بین داده‌های اندازه‌گیری‌شده و برآوردشده با استفاده از بهترین رابطة تجربی موجود به ترتیب 79، 6 و 99 و در رابطة استخراجی از مقالة حاضر 66، 1- و 44 میلی‌گرم بر لیتر است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Determination of Longitudinal Dispersion Coefficient Involving Tracer Experiment Data

نویسندگان [English]

  • Mehdi Mohammadi Ghaleni 1
  • Kumars Ebrahimi 2
  • Mohammad Hosein Omid 3
1 PhD Candidate, Water Resources Engineering, Department of Irrigation & Reclamation Engineering, University of Tehran, Karaj, Iran
2 Associate Professor, Department of Irrigation & Reclamation Engineering, University of Tehran, Karaj, Iran
3 Professor, Department of Irrigation and Reclamation Engineering, University of Tehran, Karaj, Iran
چکیده [English]

Longitudinal dispersion coefficient is normally affected by many hydraulic parameters. So far three approaches namely, integral method, dye tracing filed measurements and empirical formulae have been widely employed to estimate the above mentioned coefficient in rivers and streams. In this paper a new equation of the longitudinal dispersion coefficient is devised and evaluated using an environmentally safe tracer plus the basic empirical equations. To achieve the aim, a length of 500 meters of a manmade concrete canal was chosen, to be used in carrying out the tracer tests. A set of experiments were conducted in Feb.2015, within three different mixing lengths, of: 45, 75 and 100 meters. The results show that differences of average, variance and maximum concentration between the measured vs estimated data using the lastly available equation) are equal to 79, 6, and 99 mg/lit while using the newly equation found in the present study they are respectively equal to 66, -1 and 44 mg/lit.

کلیدواژه‌ها [English]

  • Empirical equation
  • Hydraulic Parameters
  • Mixing Length
  • tracer

مراجع

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