Global sensitivity analysis of the blade geometry variables on the wind turbine performance

Abstract

The need for implementing efficient blade designs gains relevance as wind turbine developments require longer blades. The design of blade geometry, traditionally divided in 2D airfoils and spanwise distributions, is usually addressed as an optimization problem. A correct identification of the design variables is crucial to avoid unnecessary computational cost or insufficient exploration of the design space. This paper deals with the identification of the design variables that affect the wind turbine performance.First, the number of design variables for an accurate airfoil representation is resolved. A methodology, based on statistical hypothesis testing applied to the airfoil approximation errors, is presented to assess the accuracy of types of B-splines.Second, the study is extended to chord and twist distributions besides airfoil geometry with the purpose of assessing the sensitive blade variables in the wind turbine performance. Global sensitivity analysis as multi-variable linear regressions and variance-based methods are used. Latin hypercube sampling is applied to generate efficient inputs. MATLAB-based code is developed to obtain outputs: annual energy production, maximum blade tip deflection, overall sound power level and blade mass.As result of the study, a list of non-affecting variables is deduced. These variables can be avoided in the optimization without loss of gain in the performance. The method is a powerful tool to analyse in a preliminary phase a design problem involving a high amount of variables and complex physical relations by means of combining different multi-disciplinar calculation codes and performing statistical treatments.

Quantifying the impact of sensor precision on power output of a wind turbine: A sensitivity analysis via Monte Carlo simulation study

“…A study by Kusiak and Zhang (2010) evaluated some measurable parameters of the turbine at three different WSs in three scenarios (3.5-7, 7-12, and 12-15 m/s). Echeverrı´a et al (2017) conducted an SA to identify the correct design parameters to avoid the curse of dimensionality in WT blade geometry optimization. This study provided a list of non-influential variables that can be omitted without losing efficiency.…”

Materials, Innovations and Future Research Opportunities on Wind Turbine Blades—Insight Review

“…The selection of design variables would be an important step to attain the objectives such as annual energy production, maximum tip deflection, overall sound power level, and blade mass. The airfoil geometrical variables such as leading and trailing edge geometry, a spanwise variation of airfoils and chord variables have much impact on wind turbine AEP as well as noise issues whereas chord variables highly impact on mass and maximum blade deflection . The effective design of outboard airfoils endorses the high efficiency, extreme low load, stability, and a wide operating region along with structural requirement and noise issues through a multi‐objective optimization .…”