The aerodynamic effects on a wind turbine blade's tip region are investigated using the Lifting Line Theory (LLT). The LL equation is solved using two different approaches: the Fourier Method (FM) and the Simplification Method (SM). The first method provides an accurate solution of the equation through the use of Fourier expansions and by assuming a spesific blade geometry. The latter is basically an interative method where the known results from the simple two-dimensional strip theory are implemented in the three-dimensional analysis leading to an explicit scheme. The results are presented in the form of the circulation distribution along the span of the blade and with varying tip region lengths. The aeroacoustical aspect is briefly discussed.
The Blade Element Momentum (BEM) theory is introduced and suggestions on how the LLT and the BEM can be coupled together are discussed.