The Refined Simulation Methods of Fluctuating Wind and Aerodynamic Forces Relative to Moving Trains

This study proposes a framework to accurately simulate the fluctuating wind and aerodynamic forces relative to moving trains. It provides a novel method for calculating the power spectra of the fluctuating wind relative to moving trains and the time–frequency transform for admittance function to simulate unsteady aerodynamic forces. The proposed framework demonstrates broader applicability than existing methods, particularly in complex wind environments characterized by inhomogeneity and non-stationarity. Moreover, it presents a novel method to consider the phase of admittance function in simulating aerodynamic forces relative to moving trains. Considering the wind characteristics of inhomogeneity and non-stationarity, fluctuating wind and unsteady aerodynamic forces relative to moving trains are simulated for different wind environments. The results show that fluctuating wind and aerodynamic forces relative to moving trains are more prone to be affected by inhomogeneous characteristics in a short time. The admittance function has a ‘filtering’ effect, which can filter out the high-frequency components and decrease the peak values of the aerodynamic forces. Additionally, the phase of the admittance function presents the ‘delay’ between different aerodynamic forces. Under different wind environments, the fluctuating wind and unsteady aerodynamic forces relative to moving trains are significantly different. To accurately analyze the operational safety of trains under strong wind environments, it is essential to simulate the fluctuating wind and aerodynamic forces relative to moving trains accurately.