A Comparison of Acoustic Solvers for FT Ultrasonic Wind Sensors
54º Congreso Español de Acústica — Tecniacústica 2023
Abstract
FT wind sensors measure wind speed and direction by using an acoustic field that is superimposed on a flow field in an acoustic resonator equipped with piezoelectric transducers. To improve the accuracy of wind measurements in compliance with the evolving requirements of the wind energy industry, the geometric design of FT wind sensors went through several design iterations to optimise the acoustic field and its interaction with the flow field. Finite Element based simulation tools are used to research and rapidly optimise the acoustic behaviour of FT wind sensors. The Multiphysics Research team ensures that the accuracy and reliability of the numerical methods and simulation software are adequate. In this paper, two acoustics software packages are compared, namely COMSOL Multiphysics®, a commercial software and NGSolve, an open-source general-purpose finite element library. First, a mesh convergence study is presented using a canonical 3D acoustic scattering problem. A practical application of FT wind sensors is then studied to assess the accuracy of both software. In this regard, the effect of different boundary treatments such as impedance condition and Perfectly Matched Layer are evaluated. Finally, CPU overhead of the direct solvers is also presented.