بررسی خصوصیات هیدرولیکی گرداب با هسته هوا در شرایط استغراق بحرانی با روش سرعت‌سنجی ردیابی ذرات

نوع مقاله: مقاله پژوهشی

چکیده

وقوع گرداب در سازه‌های هیدرولیکی مسئله‌ای طبیعی همراه با آثار منفی بر عملکرد این سازه‌ها به حساب می‌آید. برای شناخت بهتر این پدیده پیچیده علاوه بر مطالعات ماکروسکوپیک بر روی عمق استغراق بحرانی و سازه‌های ضد گرداب، انجام پژوهش‌های میکروسکوپیک جهت بررسی مشخصات هیدرولیکی گرداب نیز ضروری می‌نماید. در تحقیق حاضر یک جریان گردابی قوی با هسته هوا در حالت استغراق بحرانی بر روی آبگیر قائم در کانالی عریض ایجاد و مولفه‌های سه بعدی سرعت جریان با به کارگیری روش سرعت سنجی ردیابی ذرات اندازه‌گیری شد. با بررسی مولفه‌های سرعت گرداب با هسته هوا و پروفیل سطح آب، روند تغییرات خصوصیات هیدرولیکی گرداب در مسیر جریان گردابی مشخص شده و اطلاعات نوینی از ساختار سه بعدی گرداب با هسته هوا بدست آمد. بر اساس نتایج حاصل مشخص شد که روش سرعت سنجی ردیابی ذرات (PTV) می‌تواند اطلاعات مفید و نوینی از نحوه توزیع مولفه‌های سرعت در ساختار جریان گردابی ارائه دهد.                                  

کلیدواژه‌ها


عنوان مقاله [English]

Investigating of Hydraulic Characteristics of an Air-Core Vortex under Critical Submergence Condition Using Particle Tracing Velocimetry

چکیده [English]

Occurrence of the vortex in hydraulic structures as a natural problem has negative effects on the performance of the intakes. In order to better understanding this complex phenomenon, in addition to macroscopic studies on critical submergence and anti-vortex devices, microscopic studies are also employed to investigate the hydraulic properties of a vortex. In the present study, a strong air-core vortex under critical submergence condition was created on a vertical bottom intake at a wide flume then the three-dimensional velocity components of the flow were measured by a particle tracking velocimetry method. By analyzing the velocity components and water surface profile, the changes of the hydraulic characteristics of the vortex in the flow path were identified and a new information from a 3D vortex structure with the air core was obtained. Based on the results, it was found that the Particle Tracking Velocimetry (PTV) method can provide useful and new information about distribution of the velocity components in the vortex structure.

کلیدواژه‌ها [English]

  • Air-core vortex
  • Critical submergence
  • Hydraulic structures
  • Particle tracing velocimetry
  • Vertical Intake
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