نویسنده
دانشکده مهندسی مکانیک، دانشگاه صنعتی اصفهان، اصفهان
چکیده
چکیده- در بخش نخست، جریان دو بعدی کانال نیم‌موجی در عدد رینولدز 104 و شرایط بدون لغزش (سطح آبدوست) توسط برخی مدل‌های آشفتگی عدد رینولدز پایین و همچنین مدل رینولدز بالای k-ε شبیه‌سازی شده و مدل مناسب آشفتگی (1998 k-ω) معرفی شده است. سپس برای ارزیابی روش حل انتخاب شده و هماهنگی آن با شرط لغزش ناویر (سطح آبگریز)، شبیه‌سازی‌ها در جریان آشفته کانال ساده انجام گرفته و با نتایج سایر محققین مقایسه شده است. درنهایت با درنظر گرفتن مجدد جریان دو بعدی کانال نیم‌موج در عدد رینولدز 104 ، شبیه‌سازی این جریان در مجاورت سطوح آبگریز با طول لغزش‌های مختلف انجام شده است. نتایج حاکی از توانایی قابل توجه این روش در کاهش نیروی پسا است به‌نحوی که به‌ازای طول لغزش 200 میکرومتر کاهش نیروی پسای قابل توجه 38 درصد به‌دست آمده است. به‌علاوه بررسی اثر طول لغزش روی کاهش نیروی پسا نشانگر آن است که با افزایش این پارامتر، نیروی پسای اصطکاکی و فشاری کاهش بیشتری می‌یابد. همچنین برای دست‌یابی به کاهش نیروی پسای قابل توجه در جریان آشفته، نیاز است تا مقدار طول لغزش بی‌بعد از مقدار حداقلی بزرگ‌تر باشد.
کلیدواژه‌ها
عنوان مقاله [English]
Numerical Simulation of Turbulent Half-corrugated Channel Flow by Hydrophilic and Hydrophobic Surfaces
نویسنده [English]
- M. R. Rastan
چکیده [English]
In the first part of the present study, a two dimensional half-corrugated channel flow is simulated at Reynolds number of 104, in no-slip condition (hydrophilic surfaces( using various low Reynolds turbulence models as well as standard k-ε model; and an appropriate turbulence model (k-ω 1998 model( is proposed. Then, in order to evaluate the proposed solution method in simulation of flow adjacent to hydrophobic surfaces, turbulent flow is simulated in simple channel and the results are compared with the literature. Finally, two dimensional half-corrugated channel flow at Reynolds number of 104 is simulated again in vicinity of hydrophobic surfaces for varoius slip lengths. The results show that this method is capable of drag reduction in such a way that an increase of 200 μm in slip length leads to a massive drag reduction up to 38%. In addition, to access a significant drag reduction in turbulent flows, the non-dimensionalized slip length should be larger than the minimum.
کلیدواژه‌ها [English]
- Hydrophilic surface
- Hydrophobic surface
- Half-corrugated channel
- Turbulence modeling
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