Reconstruction and short-term prediction of wind pressure field on cylindrical coal sheds under undisturbed conditions using dynamic mode decomposition

Abstract

Dynamic Mode Decomposition (DMD) accurately captures growth rates and frequency characteristics of each mode, establishing a reduced-order model for the evolution of the flow field to reconstruct or predict the flow dynamics process. This study applies DMD to analyze the wind pressure distribution problem of cylindrical coal sheds, investigating its accuracy in analyzing pressure fields. First, wind tunnel tests were conducted on cylindrical coal sheds to examine the mean wind pressure coefficient distribution under typical wind directions (defined as θ). Subsequently, the wind pressure field of the coal shed was decomposed using the DMD at θ = 0°. Reconstruction with the first 15 DMD modes can better characterize the wind pressure distribution. Therefore, reconstruction with the first 15 DMD modes was chosen to reconstruct the pressure fields conducted at θ = 30°, 60°, and 90°. The DMD decomposition performance is optimal at θ = 0° for the cylindrical surface. For pressure field reconstruction in the same wind direction, as the number of modes increases, the reconstruction relative error of the pressure field decreases, thereby enhancing reconstruction accuracy and the ability to capture details. Finally, short-term predictions of the coal shed's wind pressure distribution were conducted, revealing better predictive performance near the incoming flow position. DMD can provide a basis for studying the wind pressure distribution on large-span structures such as coal sheds.