*Article* **Fluid–Structure Interaction Numerical Analysis of a Small, Urban Wind Turbine Blade**

**Michal Lipian 1,\* , Pawel Czapski <sup>2</sup> and Damian Obidowski <sup>1</sup>**


Received: 27 February 2020; Accepted: 8 April 2020; Published: 10 April 2020

**Abstract:** While the vast majority of the wind energy market is dominated by megawatt-size wind turbines, the increasing importance of distributed electricity generation gives way to small, personal-size installations. Due to their situation at relatively low heights and above-ground levels, they are forced to operate in a low energy-density environment, hence the important role of rotor optimization and flow studies. In addition, the small wind turbine operation close to human habitats emphasizes the need to ensure the maximum reliability of the system. The present article summarizes a case study of a small wind turbine (rated power 350 W @ 8.4 m/s) from the point of view of aerodynamic performance (efficiency, flow around blades). The structural strength analysis of the blades milled for the prototype was performed in the form of a one-way Fluid–Structure Interaction (FSI). Blade deformations and stresses were examined, showing that only minor deformations may be expected, with no significant influence on rotor aerodynamics. The study of an unorthodox material (PA66 MO polyamide) and application of FSI to examine both structural strength and blade deformation under different operating conditions are an approach rarely employed in small wind turbine design.

**Keywords:** small wind turbine (SWT); computational fluid dynamics (CFD); composites; fluid–structure interaction (FSI)
