مطالعه آزمایشگاهی تأثیر ارتفاع زبری بستر تنداب بر استهلاک انرژی

نوع مقاله: مقاله پژوهشی

چکیده

در این تحقیق تأثیر اندازه زبری بستر تنداب بر میزان استهلاک انرژی بررسی گردید. ابتدا پس از شناسایی پارامترهای مؤثر، رابطه‌ عمومی بدون بعد توسعه داده شد. آزمایش­ها بر روی مدل‌های فیزیکی درشیب­های 25 و 35 درجه با قرار دادن 4 نوع زبری با اندازه‌های متفاوت (38/3، 7، 7/12 و 1/38 میلی‌متر) و دانه‌بندی تقریباً یکنواخت بر روی بستر آن‌ها انجام شدند. میزان استهلاک انرژی سازه در این نوع تنداب با انجام 80 آزمایش مختلف با 10 دبی‌ بین 4 تا 40 لیتر بر ثانیه و عدد فرود 5/4 تا 9 مورد بررسی قرار گرفت. همچنین رابطه کلی جهت پیش‌بینی میزان استهلاک انرژی در این نوع تنداب ارائه و با نتایج کارهای قبلی مقایسه گردید. استهلاک انرژی در واحد طول تنداب زبر شده حدود 7 تا 38 درصد نسبت به تنداب صاف (بدون زبری) افزایش نشان داد.  

کلیدواژه‌ها


عنوان مقاله [English]

Experimental Study of Chute Bed Roughness Height Effect on Energy Dissipation

چکیده [English]

In this study the effect of chute bed roughness height on energy dissipation has been investigated. First effective parameters were identified and then a general dimensionless relationship was developed. A series of tests were conducted by a physical model using the bed slopes of 25 and 35 degrees and four different uniform roughness heights (3.38, 7, 12.7 and 38.1 mm) having uniform particle sizes on the bed. Total of 80 tests were conducted with flow discharges range between 4 and 40 L s-1 and Froude number between 4.5 and 9. A relationship was developed for prediction of energy slope on this type roughened bed chutes and the results obtained were compared with the results of previous works. Energy dissipation per unit length of the roughened chute was 7 to 38% greater than that of the smooth chute (without roughness).

کلیدواژه‌ها [English]

  • Bed roughness
  • Chute
  • Energy dissipation
  • Slope
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