Modified Savonius Wind Turbine for Wind Energy Harvesting in Urban Environments

Abstract

The flow-induced rotation of the modified Savonius rotor, for which the blade consists of a semicircular profile and an elliptical shape, is studied using a series of unsteady computational fluid dynamics (CFD) simulations. The present study first concentrates on the validation of the numerical scheme against Blackwell's experimental data of the conventional rotor. The computed flow physics around the modified rotor with the same diameter is then analyzed and compared with that of the conventional rotor during one rotation cycle. As the result, the modified rotor is outperforming the conventional one but keeping its unique features. The modified rotor offers exceeding performance at a tip speed ratio (TSR) greater than 0.8. The new peak of the power coefficient Cp is reached at TSR = 1.4 which is a typical operating condition of the wind turbine in urban areas. The remarkable finding is that the suppression of the flow separation on the blade is an effective way to improve the rotor's aerodynamic performance. As expected, the additional elliptical profile plays a key role in increasing the positive torque and in preventing the flow separation on the blade, especially at high TSR > 0.8. Finally, this study points to not only advances the fundamental understanding of flow mechanism around the rotor but also proposes good practical energy harvesting application in urban environments.

Wind Turbine Technology Trends

“…The rotation induced by the flow through a modified Savonius rotor, in which the blade consists of a semicircular profile and an elliptical shape, is studied in the work of Le et al [65] using unsteady flow simulations (CFD). The modified rotor provides excellent performance at a tip speed ratio (TSR) of more than 0.8, and the new peak power coefficient Cp is achieved at TSR = 1.4, which is the typical operating condition of wind turbines in urban areas.…”

Phân Tích Dòng Chảy Trên Bề Mặt Bằng Xử Lý Ảnh Và Ứng Dụng Trong Xác Định Trường Ma Sát Trên Bề Mặt Cánh Tam Giác

“…Trần Thế Hùng và cộng sự [3]- [7], nghiên cứu dòng chảy trên mô hình đuôi vát chỉ ra rằng, khi mô hình mô phỏng số phù hợp được lựa chọn, các kết quả tính toán tương đối đồng nhất với thực nghiệm. Lê Đình Anh và cộng sự cũng cho thấy mô hình mô phỏng số rất hiệu quả trong nghiên cứu dòng hai pha [8]- [10] cũng như ứng dụng hiệu quả trong xây dựng và tối ưu hóa mô hình tua bin gió trục đứng [11], [12]. Trong các điều kiện nghiên cứu tại Việt Nam, mô phỏng cho thấy triển vọng lớn trong nghiên cứu thiết kế với khả năng xây dựng, tính toán nhanh và chi phí phù hợp.…”

Optical-Flow and Cross-Correlation Algorithms for Analyzing Jet Flow

“…For example, Tran et al [4], [5] used Reynolds averaged Navier-Stokes equations (RANS) for an extended study of the axisymmetric boattail model. Le et al [6] used unsteady RANS to study the aerodynamic performance of vertical wind turbines. Additionally, RANS was also applied by Le et al [7], [8] for the cavitation flow phenomenon.…”