Prof. Ayman Ali Ahmed Nada :: Publications:

This paper presents the effectiveness of using mixed, nodal and/or modal coordinates in modeling wind turbines. The paper shows that the nodal model exhibits excellent numerical properties, especially in the case of highly rotations. In the case where the rotation of the rotor-blade is extremely high, the geometric stiffness effect must be taken into account, and therefore, the nonlinear stiffness terms should be included within the model. On the other side, the dynamics of the tower as well as other components can be modeled using a set of modal coordinates. The paper shows a method of utilizing experimental modal coordinates for low speed components and those that deflected by simple motion shapes. The wind-turbine model based on the floating frame of reference formulation and by using the suggested mixed coordinates can be utilized for design process, identification and health monitoring aspects.