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The development of wind energy conversion systems becomes one of the most important aims of any developing countries such as Tunisia. This is due to the reduction in wind turbine costs, and in fossil fuel atmospheric pollution. The evaluation of wind power potential is very necessary to estimate wind resource and therefore conduct the suitable decisions for the wind power generation projects, technical and economical feasibility researches. The presented work in this paper was to investigate the potential of wind resource in the Gulf of Tunis in Tunisia. The hourly mean wind speed and wind direction with a 10-min time step provided by the NRG weather station were used to analyze the wind speed characteristics and the wind power potential. Weibull parameters are estimated based on the most frequently used methods which their accuracy was compared on different goodness of fit tests. Those wind characteristics are required to give wind project users the picture of wind potential in the Gulf of Tunis.

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The aerodynamic optimization of horizontal axis wind turbine has became one of the most important challenge in the renewable energy field. Over the past few years, many researchers have drawn more attention to the physical processes of the wind energy conversion and precisely the identification of the main causes of energy losses. This paper presents an experimental investigation of near wake dynamics for a model horizontal axis wind turbine in a wind tunnel. The coherent structures downstream of the rotor were studied for different tip speed ratios using the Particle Image Velocimetry (PIV) technique. The influence of the tip vortex meandering was discussed and analyzed using the Proper Orthogonal Decomposition (POD) method. The high-energy modes show that radial meandering is the most energetic source of perturbation in each tip vortex sub-region. The energy fraction of these modes increase gradually during the development of the helical tip vortex filament, which confirm the growth of vortex wandering amplitude in the near wake.

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