Computer Aided Engineering of Wind Turbines 
Dr. J. M. Mahishi
MS&M Engineering Inc, 30665 Northwestern Hwy, Farmington Hills, MI 48334, USA
OJECTIVE
Objective is to discuss challenges in engineering and design of wind turbines and available CAE tools to solve the structural, mechanical, aerodynamic problems. The paper discusses various types of tower structures and their choice based on location, environment and cost. A tubular and a lattice tower with horizontal and vertical axis turbines are analyzed for stability under various extreme winds, seismic and thermal conditions in additions to the dynamic fluctuating loads from the rotating blades. An analysis and design optimization methodology has been developed that also takes into account the fatigue characteristics of materials used for the wind turbine towers and blades
ABSTRACT
Wind has been a source of energy for many years, but only the recent advances in technology is making it possible to harvest this energy and convert it into useful electrical energy. Since the wind energy is proportional to cube of wind velocity and wind velocity is higher and steady at over 100m from the ground, the engineering challenge now is to build as tall towers as possible.
The tall towers have to carry very large rotating mass with fluctuating wind forces. The towers themselves will also have to withstand the high wind gusts, extreme thermal and seismic loads that prevail in many wind farm sites along the west coast of North and South Americas.
The state of the art reinforced composites materials now being used for blades help reduce the rotating mass, and provide many design options to vary the stiffness along the root to tip.
A tubular and a lattice tower with horizontal and vertical axis turbines are analyzed for stability under various extreme winds, seismic and thermal conditions in additions to the dynamic fluctuating loads from the rotating blades. The fluctuating loads on rotating layered composite flexible blades at various wind speeds, including the shadow of the tower are obtained by a coupled aerodynamics and structure (aeroelastic) simulation and optimization of blades. Then the system frequency response subjected to various enforced motions including seismic excitation (accelerations from seismic maps) is evaluated.
CONCLUSIONS
The paper discusses various engineering challenges, structural and material design options and CAE tools to solve the problems through two examples. An analysis and design optimization methodology has been developed that also takes into account the thermal, hygrothermal and fatigue characteristics of materials used for wind turbine towers and blades for long time reliability.
Computer Aided Engineering of Wind Turbines
Dr. J. M. Mahishi
MS&M Engineering Inc, 30665 Northwestern Hwy, Farmington Hills, MI 48334, USA