Relation Between Angle of Attack and Atmospheric Ice Accretion on Large Wind Turbine's Blade

A numerical study of wind turbine blade profile's angle of attack variation on atmospheric ice accretion near the blade tip section was performed. Three dimensional computational fluid dynamics (CFD) based numerical analyses were carried out using NACA 64618 blade profile at five different angles of attack ranging from -5 to +7.5 degrees. Based upon the flow field calculations and the super cooled water droplet collision efficiency, the rate and shape of accreted ice was simulated for both rime and glaze ice conditions. The results show that atmospheric icing is less severe at lower angles of attack, both in terms of local ice mass and relative ice thickness.