Análise fluido-estrutural aplicada em rastreadores solares

Abstract

This work presents a fluid–structural analysis of single-axis solar trackers of the 2P type, comprising two rows of photovoltaic panels mounted on a torque tube and equipped with modules of approximately 700 W. Single-axis trackers (SATs) are essential components of modern photovoltaic power plants, enabling an increase in energy production of approximately 20% to 30%, depending on the plant latitude. The growing demand for photovoltaic energy generation has driven the increase in panel dimensions, making these systems more susceptible to wind-induced loads. Large-format modules present greater exposed areas to the wind and are therefore subject to more intense aerodynamic loading and to conditions with higher potential for aeroelastic instability. Although numerous studies in the technical literature address the aerodynamics of solar trackers, relatively few investigations focus on the fluid–structure interaction of trackers operating under aeroelastic instability-related conditions. The solution procedure adopted in the ANSYS Fluent® computational package is based on the Reynolds-Averaged Navier–Stokes (RANS) formulation for the estimation of pressure fields and the extraction of steady aerodynamic coefficients using a three-dimensional tracker model. These three-dimensional pressure fields are employed to estimate the loads acting on the tracker structure. For the dynamic analysis of vortex shedding and of regimes associated with aeroelastic instability, a two-dimensional transient model of the tracker is adopted based on the Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations. Turbulence effects are incorporated into the RANS formulation using the k-ω SST model. The formulations adopted for the dynamic flow analysis follow procedures well established in the literature.

A finite element model implemented in the ANSYS® environment is also employed to estimate the natural frequencies and vibration modes of the tracker. The evaluation of the vibratory response of the solar trackers indicates that large-format modules exhibit lower natural frequency values due to the increase in mass and mass moments of inertia. The numerical results obtained in this study indicate vortex shedding frequencies in the range of 0.7 to 0.9 Hz, which are in good agreement with data reported in the literature.

The three-dimensional structural analysis combined with the two-dimensional dynamic flow analysis enables the identification of panel tilt angles associated with designs exhibiting higher potential for aeroelastic instability. The results highlight the importance of integrating flow-related and structural analyses in the design of solar trackers employed in large-scale photovoltaic power plants.