کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6765518 | 512436 | 2016 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Numerical evaluation of the clearance geometries effect on the flow field and performance of a hydrofoil
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی انرژی
انرژی های تجدید پذیر، توسعه پایدار و محیط زیست
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Numerical evaluation of the clearance geometries effect on the flow field and performance of a hydrofoil Numerical evaluation of the clearance geometries effect on the flow field and performance of a hydrofoil](/preview/png/6765518.png)
چکیده انگلیسی
The blade tip leakage flow with efficiency losses and cavitation phenomena is a concern for the low-head tidal power units. A simplified case of NACA0009 hydrofoil in a water tunnel is used to investigate the effects of tip clearance geometries including the foil tip shape and gap width on the flow features and foil performance. Steady non-cavitating simulations are implemented for a round tip foil and a sharp tip foil with two incidence angles (α = 10° and 5°) and different normalized gap width (Ï). The minimum pressure is used to reflect the normalized vortex intensity (Î*) and cavitation characteristics. The Î*-Ï curves at different streamwise positions show that the sharp tip foil generates relatively weaker tip leakage vortex with more flat curves, but its higher Î* of tip separation vortex in wider gaps increases the risk of clearance cavitation. The flow features on a cross section inside the gap suggest that the sharp tip reduces the leakage flow losses and increases the velocity gradient due to the boundary layer separation. The lift coefficient is a little higher for the sharp tip foil than the round tip foil, with small differences for α = 5° but noticeable deviations for α = 10° especially within 0.3<Ï < 1.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Renewable Energy - Volume 99, December 2016, Pages 390-397
Journal: Renewable Energy - Volume 99, December 2016, Pages 390-397
نویسندگان
Qiang Guo, Lingjiu Zhou, Zhengwei Wang,