Mathematical optimization of constructive parameters in the behavior of vertical axis wind turbines with straight blades

Abstract

Due to researches developed on wind Energy, it has been possible to note the influence of different constructive characteristics (Alignment angle, height, radius and solidity) over the power coefficient Cp. This paper proposed an optimization method, which objective is maximizing the Cp integrating all geometric characteristics mentioned before. The importance of this work is based in the fact that the most part of results of research actions on this field have been obtained through wind tunnel experiments, in which each parameter is individually evaluated. The computational models developed (CFD) have been focused in demonstrate their validity comparing their results with the dates obtained experimentally. Nevertheless, it is hard to find a research which its objective has been determine the influence of different constructive characteristics, studying its behavior simultaneously. The calculation procedure was based on selecting geometrical parameters to the optimization model. Considering that Cp is different for each TSR value and it is the parameter to optimize. The objective function was defined as the area below the curve Cp vs TSR (Tip Speed Ratio). As starting point were taken the parameters cited by several authors (relation HR, solidity S, alignment angle γ,). The results provide evidence of studying simultaneously the influence of constructive characteristics on which Cp depends, allow reach the same performance as the horizontal axis wind turbine and besides overcome problems in the starting, which is the main cause for disinterest in investigating vertical axis turbines.