AdaptFoil3D II

Comunicaciones en congresos

• • “Along-the-path exponential integration for Floquet stability analysis of wind turbines” en el congreso internacional bienial TORQUE, celebrado el 1-3 junio en la universidad TU Delft (Paises Bajos). Así mismo, el artículo correspondiente será publicado como acta de congreso en Journal of Physics: Conference Series.

The goal of the AdaptFoil3D II project is to provide industry with high-fidelity and low computational cost aerodynamic simulation tools.

The aerodynamics of a wind turbine is a key element in the energy production of wind turbines. Since the start of the wind power industry, the theories used for designing and estimating the energy of wind turbines has been based on simple aerodynamic theories from the aerospace industry, alongside some experimental corrections to take complex effects into account, and they are not described very well by BEM theory. Thus, local effects at the blade hub and tip or situations where wind turbine blades are subjected to winds far outside their normal operating position are not represented very well by the theories and formulations currently being done, because they are based 100% on experimental observations. Traditional tools are very fast, however for some complex wind situations those solutions are not very accurate or clearly wrong.

The theories based fundamentally on experimentation are proven using very complex CFD calculations with long computation times that make them unviable for extensive use. Because of that, CENER has developed an aerodynamic module called AEROWIN that can be integrated into any aeroelastic simulation software, including the kind in use currently. AEROWIN can do simulations like the ones that can be done reliably with BEM theory with the same precision, but it can also handle complex situations far outside nominal situations that the BEM models do not represent correctly. In addition, the computational cost of AEROWIN is moderate, and it can run on a simple desktop PC in a length of time that meets the needs of industry that require massive launches of loads.

But AEROWIN is not just capable of suitably solving problems like large misalignments between the wind and wind turbine blades. AEROWIN, in contrast to all the BEM code, is also able to capture a fact that is not possible with BEM theory and that is crucial for the large wind turbines of the future. Large rotors, much larger than 200 m, that are being designed are very flexible structures that can deflect 10 or 15 metres while spinning. That means that in one rotation of the rotor the blade can be closer or farther from the tower. That means that in those cases the rotor can come into contact with its own wake, causing a physical effect that was not as important or frequent with 40 metre rigid blades. That physical effect is even more pronounced in future floating wind generators, supported by floating devices, that will undergo constant forward and backwards movements. AEROWIN can capture that effect, because AEROWIN can calculate the wake produced by a wind generator and, consequently, it can take it into account when calculating the aerodynamic effects produced in a wind generator.

AEROWIN has been the subject of several recent publications by CENER. Some of the publications have raised a lot of interest in the industry, and right now CENER is working on integrating AEROWIN into a commercial tool widely used in the wind energy industry.