Factors of physical model and computational

AcknowledgmentsThe authors acknowledge with thanks the financial support provided by the National Science & Technology Pillar Program during the 12th Five-year Plan Period (Grant No. 2011BAJ03B07), Hunan Provincial Natural Science Foundation of China (Grant No. 14JJ3100), Postdoctoral Science Foundation of China (Grant No. 2013M542140) and Postdoctoral Science Foundation of Central South University (Grant No.126640). We also deeply thank the anonymous reviewers for their thoughtful suggestions that resulted in a much improved revision of this A 80426 paper.
Small wind turbine; Hollow blades; Aero-structural design; Starting time; Optimization; Genetic algorithm
1. Introduction
Output power from wind turbines is the main goal during the design and optimization of the wind turbine blades. However, this is not the whole story. As the blades size increases, the blade mass and the noise produced by the blades should also be taken into account as important parameters during the blade design. Small wind turbines (SWTs), however, which have a maximum power output of about 50 kW as defined by the International Electrotechnical Commission (IEC) Standard 61400-2 [1], have some different design requirements [2]. SWTs are often used off-grid where they must produce as much power as possible over a short period of time when a modest wind begins to blow. Furthermore, SWTs generally have no pitch adjustment to optimize the angles of attack during starting contrary to their large counterparts which are equipped with advanced pitch control mechanisms. So, the rapid starting of SWTs is an important factor which should be considered during the blade design [2].