بررسی تجربی ویژگی های جریان در اطراف یک سیلندر بیضوی تحت تأثیر سیم اغتشاش ساز

نویسندگان

دانشکده مهندسی مکانیک دانشگاه حکیم سبزواری

چکیده

در این تحقیق به بررسی تجربی رفتار و مشخصه‌های دنباله جریان حول یک سیلندر بیضوی با زاویه حمله صفر درجه، تحت تأثیر سیم اغتشاش سازی با قطر 1 میلی‌متر پرداخته شده است. بدین منظور، از یک استوانه با سطح مقطع بیضوی از جنس آلومینیوم، دارای طول mm 390، قطر بزرگ mm 4/42 و قطر کوچک mm 2/21 استفاده شده است. مدل سیلندر در اتاقک آزمون یک دستگاه تونل باد دمشی مورد آزمایش قرار گرفته است. اعداد رینولدز آزمایش نسبت به قطر بزرگ سیلندر برای سرعت‌های m/s 10 و m/s 20 به‌ترتیب 25700 و 51400 می‌باشند. سیم اغتشاش ساز به‌صورت متقارن روی سیلندر بیضوی، در زاویه‌های صفر درجه، 7/23 درجه و 9/40 درجه نسبت به نقطه سکون مورد آزمایش قرار گرفته است. ضریب پسا برای سیلندر بیضوی صاف در هر دو عدد رینولدز در حدود 6/0 است. نتایج نشان می‌دهند که در بهترین حالت ممکن، در زاویه نصب 7/23 درجه، ضریب پسا به میزان 5/56% کاهش می‌یابد. همچنین، در بهترین حالت ممکن برای زاویه صفر درجه ضریب پسا 6/8% کاهش می‌یابد، درحالی‌که در بدترین حالت ضریب پسا برای زاویه 9/40 درجه به‌اندازه 7/20 % افزایش دارد.

کلیدواژه‌ها

مراجع

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  • تاریخ دریافت: 25 اردیبهشت 1396
  • تاریخ بازنگری: 03 اسفند 1401
  • تاریخ پذیرش: 28 شهریور 1397
  • تاریخ انتشار: 30 اسفند 1395

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