بررسی عددی فرآیند کاهش پسا در جریان آرام با استفاده از ریبلت‌های مستطیلی

نوع مقاله : مقاله کوتاه

نویسندگان

• امیر حاجی‌خان میرزایی
• علیرضا رئوف پناه

دانشگاه آزاد اسلامی واحد یادگار امام خمینی (ره)‏

10.22067/fum-mech.v31i1.79677

چکیده

هدف اصلی در پژوهش حاضر معرفی روشی کارآمد و بدون نیاز به ابزارهای بیرونی جهت کاهش پسای وارد بر اجسام متحرک در سیّالات است. رژیم جریان سیّال آرام در نظر گرفته شده است. ابزار مورد نظر ریبلت‌های مستطیلی می‌باشند که به‌صورت عمود بر حرکت جریان سیّال قرار گرفته‌اند. میدان جریان روی سطوح ریبلت‌دار با استفاده از دینامیک سیّالات محاسباتی در فضای دوبعدی به‌دست‌آمده است. اثر پارامترهای هندسی ریبلت‌ها شامل عرض و ارتفاع و هم‌چنین اندازه سرعت جریان آزاد بر میزان کاهش پسای وارد بر سطوح ریبلت‌دار نسبت به سطح صاف بدون ریبلت مورد بررسی قرار گرفته است. نتایج به‌دست‌آمده نشان از کارآمدی روش مذکور در کاهش پسای وارد بر سطح در رژیم جریان آرام دارد. حداکثر کاهش پسا در عرض ریبلت 1/0 میلی‌متر و سرعت جریان آزاد 10 متر بر ثانیه برابر با 7/8 درصد محاسبه شده است.

کلیدواژه‌ها

• ریبلت
• آب‌گریز
• کاهش درگ
• شبیه‌سازی عددی
• دینامیک سیالات محاسباتی‏
• کاهش پسا

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عنوان مقاله [English]

Numerical Investigation of Drag Reduction Mechanism in Laminar Flow Regime using Rectangular Riblets

نویسندگان [English]

• Amir Haji Khan Mirzaei
• Alireza Raoufpanah

Islamic Azad University, Yadegar-e-Imam Khomeini (rah) Branch‎

چکیده [English]

This paper aims to introduce an efficient and passive method in order to reduce the amount of drag exerted on the surfaces of the objects moving in the water. The flow regime is considered as laminar. The desired method is to use rectangular riblets being perpendicular to the flow direction. Two-dimensional computational fluid dynamics is utilized to resolve the flow field around the ribbed surfaces. The effects of geometrical parameters of riblets including width and height as well as free-stream velocity on the amount of drag reduction are numerically calculated. The numerical results certify the efficiency of rectangular riblets as a drag reduction tool in the laminar flow regime. Maximum amount of the drag reduction is about 8.7% achieved for the riblets width of 0.1 millimeter and at free-stream velocity of 10 m/s.

کلیدواژه‌ها [English]

• Riblet
• ‎, Hyrophobic
• Drag reduction
• Numerical simulation‎
• computational fluid dynamics

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