مشخصات هیدرولیکی جریان در حوضچه‌های آرامش دایره‌ای با بلوک‌های آرام‌کننده

نوع مقاله : پژوهشی

نویسندگان

1 دانشکده‌ی مهندسی عمران، دانشگاه صنعتی اصفهان، اصفهان، ایران.

2 دانشکده‌ی مهندسی عمران و محیط زیست، دانشگاه تربیت مدرس، تهران، ایران.

10.24200/j30.2024.64524.3330

چکیده

یکی از متداول‌ترین انواع سازه‌های استهلاک انرژی، حوضچه‌های آرامش هستند. حوضچه‌های آرامش دایره‌ای با توجه به کاهش دبی در واحد طول قوس حوضچه در مقایسه با دیگر انواع حوضچه‌های آرامش، مشخصات هیدرولیکی بهینه‌تری دارند و در صورت اضافه‌کردن بلوک‌های آرام‌کننده، مشخصات هیدرولیکی حوضچه‌های آرامش بهبود می‌یابد. هدف از مطالعه‌ی تجربی حاضر، بررسی ویژگی­های هیدرولیکی جریان درون حوضچه­های آرامش دایره­ای با بلوک­های آرام­کننده است. برای این منظور، ضمن بررسی فیزیک پدیده و تأثیر هر یک از پارامترهای مؤثر، به مقایسه‌ی مشخصات هیدرولیکی جریان درون حوضچه­های آرامش دایره‌ای با دیگر حوضچه‌های آرامش پرداخته شده است. ضمناً روابط تجربی برای محاسبه‌‌ی نسبت اعماق مزدوج پرش و افت نسبی انرژی در حوضچه‌های آرامش دایره‌ای با بلوک‌های آرام‌کننده ارائه شده است. نتایج به‌دست‌آمده بیان­گر کاهش کمینه‌ی 15٪ نسبت اعماق مزدوج و افزایش کمینه‌ی 10٪ افت نسبی انرژی در مقایسه با حوضچه­های آرامش کلاسیک در شرایط هندسی-هیدرولیکی یکسان بوده است. براساس نتایج پژوهش حاضر، امکان شکل­گیری سه نوع پرش نوسانی، پایدار، و قوی درون حوضچه­های آرامش دایره‌ای وجود دارد. نزدیکی پروفیل پرش به شکل سهموی از دیگر نتایج پژوهش حاضر به­شمار می­رود. درنهایت، روابط تجربی استخراج‌شده با کمک شاخص‌های خطا ارزیابی شده است، که انطباق مطلوبی (حدود ۹۵٪) با داده­های آزمایشگاهی داشته است. 

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Hydraulic Characteristics of Flow in Circular Stilling Basins with Baffle Blocks

نویسندگان [English]

  • Hamed Dashtban 1
  • Abdorreza Kabiri-Samani 1
  • Mostafa Fazeli 2
1 1Department of Civil Engineering, Isfahan University of Technology, Isfahan, Irangy
2 Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran
چکیده [English]

One of the most common hydraulic structures to dissipate the excess destructive flow energy is a stilling basin of the hydraulic jump type. Compared to the other types of stilling basins, due to the reduction of flow per unit arc length, in circular stilling basins, the hydraulic performance is improved, which can be more efficient if it comprises a number of baffle blocks on the bottom of the basin. Most of the former research on circular hydraulic jump stilling basins has focused on categorizing their types and hydraulic characteristics and recommended some limited design guidelines, overlooking the effectiveness of the baffle blocks inside a circular hydraulic jump. Considering the positive effect of the baffle blocks on improving the hydraulic characteristics of the classical and radial hydraulic jumps, it is expected that, compared to the typical circular basins, a circular stilling basin with baffle blocks would be more efficient. Therefore, identification of the hydraulic characteristics of the circular stilling basins with baffle blocks still needs further investigation. The present experimental study subjects to investigate the hydraulic characteristics of the circular hydraulic jump-type stilling basins with the angled baffle blocks. Examining the hydraulic characteristics of the circular stilling basins with baffle blocks, empirical relationships are derived for the sequent depth ratio and the relative energy loss in the circular stilling basins with baffle blocks. The extracted empirical equations are evaluated, applying sensitivity and error analyses. The physics of the phenomenon, effects of the prevailing dimensionless parameters, and the profile of the jump surface are also discussed. Furthermore, the present results are compared with those of the other types of stilling basins. The characteristics of the circular stilling basins with the baffle blocks, such as the sequent depth ratio and relative energy loss increase, and the relative jump length decrease, are compared to the classical hydraulic jump-type stilling basins. The present study is a starting point for the investigation of the circular hydraulic jumps in a plunge pool. More experimental/theoretical studies are obligatory to analyze the hydraulic characteristics of the circular hydraulic jumps, changing the bottom slope, the flow discharge, and the water free-surface profile.

کلیدواژه‌ها [English]

  • Hydraulic jump
  • circular stilling basin
  • baffle blocks
  • relative energy loss

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