بررسی عددی ساختار جریان و عملکرد پمپ سانتریفیوژ با رخداد کاویتاسیون

نوع مقاله : مقاله پژوهشی

نویسندگان

1 عضو هیات علمی دانشگاه صنعتی اراک

2 Arak university of technology

چکیده

در مقاله حاضر، شبیه سازی عددی جریان جهت شناسایی رخداد کاویتاسیون و جزئیات شکل گیری و اثرات آن، در پمپ سانتریفیوژ از نوع 250- 100 شرکت پمپیران با نرم افزار انسیس سی – اف – ایکس پرداخته شده‌است. در شبیه سازی کاویتاسیون، جریان به صورت دو فاز آب و بخارآب در نظر گرفته شده‌است. از معادله رایلی- پلست جهت بررسی رشد و فروپاشی حباب بخار استفاده شده‌است. به منظور اعتبارسنجی نتایج عددی، منحنی‌های مشخصه پمپ از مطالعه حاضر استخراج و با نتایج مشابه تجربی مقایسه گردیده است. میزان انحراف نتایج عددی حاضر با نتایج تجربی در دبی طراحی پمپ 6/5 درصد می‌باشد. مشخص می‌گردد که کاویتاسیون در فشارهای ورودی کمتر از 45 کیلو‌پاسکال رخ می‌دهد. با کاهش فشار ورودی از 40 کیلوپاسکال تا 20 کیلوپاسکال، میزان جدایش جریان افزایش یافته و موقعیت آن از ابتدای پره به نواحی داخلی پره منتقل می‌شود. موقعیت رخداد کاویتاسیون در0/14 تا 0/24 گذرگاه و همچنین ابتدای پره‌ها رخ می‌دهد. به نحوی که کاویتاسیون لبه حمله به سمت مناطق داخلی پره انتقال می‌‌یابد. میزان کسر حجمی بخار در این قسمت‌‌ها به ترتیب از 0/04 به 0/96 افزایش یافته‌است. با رخداد کاویتاسیون در هد مکش مثبت خالص برابر با 1/52، افت 3 درصدی هد مشاهده می‌گردد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Investigation of Flow Structure and Performance of Centrifugal Pump with Cavitation

نویسندگان [English]

  • sarallah Abbasi 1
  • hasan gholizadeh 2
1 assistant professor, Arak university of technology
2 Arak university of technology
چکیده [English]

In the present paper, the numerical simulation of the flow to identify the cavitation and its effects inside the centrifugal pump of 100-250 type of Pumpiran Company, including the impeller and volute of the pump, has been done. The Rayleigh–Plesset equation was employed to study the growth and collapse of the vapor bubble. In order to validate the numerical results, the pump curves were extracted from the present study and compared with similar experimental. The deviation of the present numerical results with the experimental ones in the pump design flow rate is 6.5%. It is found that cavitation occurs at inlet pressures of less than 45 kPa. By reducing the inlet pressure from 40 kPa to 20 kPa, the flow separation rate also increases and its position is transferred from the beginning of the blade to the inner areas of the blade. The position of cavitation occurs at 0.14 to 0.24 of the passage as well as at the beginning of the blades. The volume fraction of steam in these parts has increased from 0.04 to 0.96, respectively. With cavitation in the net positive suction head equal to 1.52, a 3% drop of the head is observed in the diagrams.

کلیدواژه‌ها [English]

  • Numerical simulation
  • Cavitation phenomenon
  • Centrifugal pump
  • Performance curve
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