An empirical and computational method for performance evaluation of vertical axis wind energy capture system.

摘要

This Dissertation presents the author's investigation and development of a systematic method for evaluating the aerodynamic performance of Vertical Axis Wind Energy Capture Systems (WECS) apart from their electrical generation capability.;The current standard method for specifying a wind energy machine is to discuss its rated power in kilowatts (or megawatts when capacity exceeds 100 kW). While this holistic method is effective for comparing machines it does not reveal the essential characteristics necessary for optimization of individual machine components.;The method developed herein separates the performance characteristics of the WECS from the generation characteristics and isolates them for benchmarking and optimization.;In order to develop an evaluation criterion, it was essential to evaluate and benchmark the current state of the art for wind energy capture. A thorough history of Vertical Axis Wind Turbine (VAWT) development and technology transfer, a standardized set of VAWT terms and a complete taxonomy of WECS types are included to ensure comparisons remain appropriate and within the same class of machine.;Existing analytical methods for WECS and wind energy airfoils are surveyed and appropriate methods are selected and presented for establishing lift, drag, solidity, and specific power. A novel technique is developed for more accurately calculating VAWT solidity and is presented along with the numerous historical methods for solidity calculation.;Empirical methods are presented for characterizing advance ratio and aerodynamic coefficient of performance. Results show that a VAWT can be optimized aerodynamically without consideration of generator efficiency using low capital cost rapid prototyping methods and an unsophisticated open loop wind tunnel.;Wind tunnel model production with a rapid prototyping machine and kilowatt scale prototyping using composite material fabrication are discussed. Fixed and mobile test tower design and instrumentation are presented along with a summary of the variety of WECS devices that were considered and constructed as part of this project.;An in-situ run through of each of the proposed numerical and empirical evaluation techniques is demonstrated for a novel, patented vertical axis wind machine and the reduction to practice of the turbine design that occurred as a part of the project is detailed.