Similarity solution for sectional A2∗ aerodynamic derivative for single axis solar trackers at various angles of attack and ground distances

Based on the experimental data of the aerodynamic derivative $A_2^{\ast }$ presented in the literature, evidence was found that supports the existence of a similarity solution between $A_2^{\ast }$, the effective mean angle of attack, ${\alpha }_{mean}^{eff}$, the tracker height-to-width ratio, $H/B$, and the reduced velocity. $U_r$. With this similarity solution, it is possible to estimate $A_2^{\ast }$ for any ${\alpha }_{mean}^{eff}\in \left(-40°,+40°\right)$ and $H/B\in \left(0.3,2.0\right)$ with a significantly reduced amount of experimental data. This represents a notable advancement compared to the current state of the art, as it could allow for a more detailed analysis of aeroelastic instability in flat solar trackers with fewer experimental requirements. This article presents the developed formulation and the process followed to obtain the discovered similarity solution. Relying on the similarity solution, a simplified model of $A_2^{\ast }$ has been proposed as a function of the reduced velocity and $H/B$ for ${\alpha }_{mean}^{eff}=0°$.