NUMERICAL STUDY OF NON-UNIFORM CHORD LENGTHS AND TWISTS ON HORIZONTAL AXIS WIND TURBINE TO ENHANCE ITS PERFORMANCE Nu Rhahida Arini, Arizal Fatkhur Rakhman Sidiq, and Amir Fadhilah
Department of Mechanical and Energy, Politeknik Elektronika Negeri Surabaya, Surabaya, Indonesia
Abstract
Wind energy is a promising renewable resource that can be converted into electricity utilizing turbines and generators. The energy conversion process influences electricity generation due to the production of lift and drag forces in which the turbine blade profile plays an important role. This research aims to numerical study modified Horizontal Axis Wind Turbines (HAWTs) blades using Computational Fluid Dynamics (CFD) method to enhance the turbine performance. This CFD procedure utilizes OpenFOAM tool and examines the three-blade design modifications. The blade modification incorporates NACA 0015 airfoils with non-uniform chord lengths and twists. The modification is confirmed using the lift coefficient (CL), and drag coefficient (CD). Pressure contour, velocity distribution, and streamline flow are evaluated to confirm the improvement. The Blade Element Momentum (BEM) theory is applied to ensure the procedure with the limitation. It is found that, despite its widespread use, BEM has limitations often underestimating forces near the root and overestimating performance near the tip. In this research aims to optimize turbine design by adjusting chord lengths and incorporating the BEM theory. The result of the nonuniform chord length and twisting can produce 19,8% higher power. The study also explores the new blade localization theory for adaptive machining and manufacturing tolerances.
Keywords: Horizontal Axis Wind Turbine (HAWT), Computational Fluid Dynamics (CFD), Blade Element Momentum (BEM) Theory, OpenFOAM, NACA 0015, Wind Energy Conversion, Turbine Blade Design, Renewable Energy
