Session: 41-02 Experimental research

Paper Number: 124372

124372 - Optimum Design of Scaled-Down Wind Turbines Based on Field Data 

This paper presents a method for designing and testing wind turbine-scaled models based on field data. Scaling models requires careful consideration of the studied system’s physical laws and similarity criteria. The choice of scaling method depends on the specific problem and the desired Similarity between the scaled model and the full-sized system. The data from a field turbine is the input for creating a scaled model and testing it in a wind tunnel. Several publications deal with this topic for wind turbines and other applications such as buildings, aircraft wings, propellers, and aerospace devices. The design of scaled models is crucial for predicting wind turbine operating conditions and validating new turbine designs. But, the drawback of the scaling models is their inability to reproduce all the operating conditions. Thus, the method presented here considers the majority of the similarity recommendations, including the dynamic modeling of the system.

The first Similarity is the Geometric Scaling: The diameter of the rotor is scaled to keep the same tip ratio. The tip ratio was selected considering the wind speed range based on the field measurements and the wind tunnel conditions. The other scaling factors, such as the Reynolds and Froude numbers, are verified at this point.

Dynamic Similarity was the second condition. The scaled model is redesigned to have similar trust and drag forces (with respect to the rotor’s torque). The Reynolds and Strouhal numbers are also verified to satisfy the geometric Similarity. The commitment is between the aerodynamic loads, the actual power, and the equivalent trust and drag forces. Due to the construction of the scaled model, the kinematic viscosity is neglected.

Material Properties: The stiffness and density were chosen to match the full-sized system frequencies. These factors included the tower design since its dynamic response affects the wind turbine behavior.

The scaled model has a different blade design optimized to achieve all the similarity criteria. The new model kept the original twist angle, but the BEM theory recalculated the other parameters.

The scaling procedure considered the wind tunnel dimensions and the field data from an actual wind turbine. The flow conditions were scaled, viewing the real wind profile registered at the site. The wind tunnel results were compared with the field data measurements.

Presenting Author: Juan Jauregui University of Queretaro

Presenting Author Biography: Juan Carlos Jauregui works as a Professor at Universidad Autonoma de Queretaro where he conducts research in design and dynamics of machinery.

He has been involved in the design and operation of different automatic machines, and three 12m wind turbines. He has published several journal and conference papers, book chapters, and five research books. He has belonged to ASME since 1991 and he is Fellow member.

He is also member of the Executive Committee of the International Federation for the Promotion of Machines and Mechanisms (IFToMM)

Authors:

Juan Jauregui University of Queretaro
Jesus Alejandro Franco Escuela Nacional de Estudios Superiores Juriquilla UNAM