Optimization of Wind Turbine Airfoil Using Nondominated Sorting Genetic Algorithm and Pareto Optimal Front

A Computational Fluid Dynamics (CFD) and response surface-based multiobjective design optimization were performed for six different 2D airfoil profiles, and the Pareto optimal front of each airfoil is presented. FLUENT, which is a commercial CFD simulation code, was used to determine the relevant aerodynamic loads. The Lift Coefficient ( ) and Drag Coefficient ( ) data at a range of 0° to 12° angles of attack ( ) and at three different Reynolds numbers ( , 479, 210, and 958, 422) for all the six airfoils were obtained. Realizable turbulence model with a second-order upwind solution method was used in the simulations. The standard least square method was used to generate response surface by the statistical code JMP. Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) was used to determine the Pareto optimal set based on the response surfaces. Each Pareto optimal solution represents a different compromise between design objectives. This gives the designer a choice to select a design compromise that best suits the requirements from a set of optimal solutions. The Pareto solution set is presented in the form of a Pareto optimal front. 1. Introduction According to the US Department of energy, the combustion of fossil fuels results a net increase of 10.65 billion tones of atmospheric carbon dioxide every year [1] which deteriorates the environmental balance. Fossil fuels also give out sulfur dioxide into the air, which, after reacting with the moisture in air, produces sulfuric acid and leads to acid rain. Furthermore, depletion of these nonrenewable sources of energy is taking place at a rapid pace because of the increasing demands of energy, with the modernization of our society. Estimates from the US Department of Energy predict that the years of production left in the ground for oil are 43 years, gas 167 years, and coal 417 years [2]. Therefore, it is critical that we start looking for some renewable sources of energy that can be used as alternatives to fossil fuels. Renewable energy resources can play a key role in producing local, clean, and inexhaustible energy to supply the growing demand for electricity, heat, and transportation fuel. Wind energy as a source of energy to produce electricity is favoured widely as an alternative to fossil fuels. It is plentiful, renewable, widely distributed, and clean and produces no greenhouse gas emissions. Wind turbines convert kinetic energy from the wind into mechanical energy which can be used to generate electricity. When the wind blows and flows around the blades of the wind turbines, which have