Aerodynamic and Structural Integrated Optimization Design of Horizontal-Axis Wind Turbine Blades

Abstract

Abstract:A procedure based on MATLAB combined with ANSYS is presented and utilized for the aerodynamic and structural integrated optimization design of Horizontal-Axis Wind Turbine (HAWT) blades. Three modules are used for this purpose: an aerodynamic analysis module using the Blade Element Momentum (BEM) theory, a structural analysis module employing the Finite Element Method (FEM) and a multi-objective optimization module utilizing the non-dominated sorting genetic algorithm. The former two provide a sufficiently accurate solution of the aerodynamic and structural performances of the blade; the latter handles the design variables of the optimization problem, namely, the main geometrical shape and structural parameters of the blade, and promotes function optimization. The scope of the procedure is to achieve the best trade-off performances between the maximum Annual Energy Production (AEP) and the minimum blade mass under various design requirements. To prove the efficiency and reliability of the procedure, a commercial 1.5 megawatt (MW) HAWT blade is used as a case study. Compared with the original scheme, the optimization results show great improvements for the overall performance of the blade.

Multi-Objective Aerodynamic and Structural Optimization of Horizontal-Axis Wind Turbine Blades

“…The airfoil locations are reflected by the percent thickness distribution, as illustrated Once the geometry shape of the blade is fixed, the aerodynamic loads can be calculated using BEM theory [20,21] by dividing the blade into several independent elements. Aerodynamic loads including operational case and ultimate case for the optimization design in this paper are the same as the loads in [19]. The operational case takes into account the maximum root flap bending moment Mflap under operational state, which is computed as follow: 2 2 4πρ (1 )…”

“…In this paper, the constraints are: (1) geometrical shape [19]: the twist, chord and percent thickness distributions are required to monotonically decrease; (2) material layup: the number of layers shown in Figure 7 need to increase to a maximum value and then decrease, the location of layers need to monotonically increase; (3) maximum strain [25]: to meet the strength requirement, the maximum strains of GFRP ε maxG and CFRP ε maxC can not exceed the allowable values ε dG and ε dC , respectively; (4) maximum tip deflection [26]: to avoid the risk of blade and tower collision, the maximum tip deflection d max must be limited to a design value d d ; (5) natural frequency [27]: to prevent resonance, the first natural frequency of the blade F blade−1 should be separated from the integral multiple of the rotor rotation frequency F rotor ; (6) buckling load [28]: the lowest buckling eigenvalue λ 1 is required to be larger than a safety factor to avoid buckling failure.…”

“…In order to improve the overall performances of HAWT blades, a new optimization procedure with three modules is developed based on the one in [19]. Figure 8 shows the flowchart of the procedure.…”

“…Most of the works among these papers either taken a single objective function in the problem or used beam models to calculate the structural behaviors, the material layup was not discussed. Our recent research [19] described a multi-objective optimization method for the aerodynamic and structural integrated design of blades to maximize the AEP and minimize the blade mass, finite element method (FEM) was applied so that the layup variation could be described, but the cost was not evaluated due to no CFRP usage. This paper presents a procedure for the multi-objective aerodynamic and structural optimization of HAWT blades based on the one in [19].…”

“…Our recent research [19] described a multi-objective optimization method for the aerodynamic and structural integrated design of blades to maximize the AEP and minimize the blade mass, finite element method (FEM) was applied so that the layup variation could be described, but the cost was not evaluated due to no CFRP usage. This paper presents a procedure for the multi-objective aerodynamic and structural optimization of HAWT blades based on the one in [19]. The blade element momentum (BEM) theory is used to evaluate the aerodynamic performances, the FEM method is applied to calculate the structural behaviors.…”