Papers by Author: Fang Feng

Abstract: With the advance of computer technology, numerical simulations were widely used for designing wind turbine. Savonius rotor is a kind of drag type wind turbine often used for water pumping for its good torque performance. In this study, numerical computations were carried out based on three different turbulence models including Splart-Allaras (S-A) model, k-εmodel and k- ωmodel to compute the static torque performance at different attack angles. Flow fields around the Savonius rotor were obtained. Comparing the computation results with the experimental results, the effects of turbulence models on the static performances of the Savonius rotor were discussed. The simulation result based on k-ω model was in agreement with test data generally.

Abstract: In recent years, vertical axis wind turbine is widely used. However, when it is installed in cold regions icing and snow on blade surface will occur in winter. To simulate the situation of icing, computer simulations were carried out on a NACA0015 airfoil which is often used for vertical axis wind turbine. The computations were based on the N-S equation in 2D incompressible steady flow with using the DPM (Discrete Phase Model) to calculate icing. Under the different wind speeds and cold water discharges in cold air, the icing distributions on airfoil at 8 kinds of typical attack angles were calculated. The icing area on the leading edge and trailing edge of blade airfoil were also obtained. Based on these results, the factors affecting the icing on blade surface including wind speed, attack angle and cold water flow discharge were discussed. With the increasing of the flow discharge, the icing area ratio increases and ice accretions become more and more dense.

Abstract: Recently, the straight-bladed vertical axis wind turbine (SB-VAWT) receives more and more attentions for its simple design, low cost, and good maintenance. The torque performance of the SB-VAWT is greatly affected by the blade airfoil. In order to research the static torque characteristics of SB-VAWT with symmetrical and non-symmetrical blade airfoil, numerical simulations by 2D CFD method were carried out on three kinds of blade airfoils including NACA0018, NACA2418 and NACA4418 at different azimuth angles. Furthermore, the static torque coefficient of the SB-VAWT with four blades with the three kinds of blade airfoils was calculated. The pressure and velocity fields were also obtained to analyze the static torque performance. Based on these results, the effects of blade airfoils on the starting torque performance of the SB-VAWT were compared and discussed.

Abstract: Icing on blade surface of the wind turbine set in cold regions is a serious problem. To invest the mechanism of icing and ice accretion on blade surface, wind tunnel tests were carried out on a static straight blade used for the straight-bladed vertical axis wind turbine by using an icing wind tunnel. The icing and ice accretions on blade surface at some typical angles of attack were observed and recorded in a fixed wind speed and steady flow discharge. The mass of ice accretions on the surface of blade were also measured and compared. At the same time, the drag and lift coefficients were tested by a three-component force balance. Based on the test results, the factors affecting the mass and characteristic of ice accretions and the drag and lift coefficients of the straight blade were discussed.