Flow And Turbulence Characteristics Through A Vertical-Axis Wind Turbine Using Eddy Covariance Method
Loading...
Date
2016-02
Authors
H’ng, Yin Mun
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Vertical-axis wind turbine (VAWT) is claimed to be effective in low wind speed conditions. The objectives of this research are to assess the turbulence and flow characteristics of upwind and wake of a VAWT based on different flow speeds, to determine the lateral and vertical profiles of upwind and in the wake of a VAWT and to determine the spectral characteristics of turbulence in the wake of VAWT using the eddy covariance method. To characterize the flow and obtain direct measurements of turbulence of a VAWT, the experiment is conducted in a controlled indoor laboratory to avoid the complex nature of outdoor wind. The flow source was simulated by three 26" industrial standing fans arranged in a row at different speed settings. The three dimensional flow velocities fluctuations were measured by an ultrasonic anemometer at 10 Hz in order to cover most turbulence scales. A preliminary study showed that the time series of flow velocities were similar to the outdoor turbulence condition. Results show that blocking effect of the VAWT affects the upwind flow and produced a backflow at the countercurrent direction of the flow source. Momentum transfers vertically from left to right column in the wake of VAWT. Spectra power showed that the energy carried by eddies above and in the wake of VAWT reduced from left to right. This research provides a direct measurement dataset and serves as a baseline data to understand the turbulence and flow characteristics of the VAWT using the eddy covariance method.
Description
Keywords
Wind