Turbulence evolution and vortex shedding dynamics of a rectangular plate moving through steady flow

Using large-eddy simulation, we investigate turbulence evolution and vortex shedding dynamics around a rectangular plate moving transversely through steady flow, focusing on the roles of the dimensionless pressure difference (P*) and plate velocity (V*). The results show that P* is the dominant control parameter: as P* increases from 0.2 to 1.0, the difference in the front-to-rear pressure coefficient increases from 0.67 to 4.88, whereas the peak fluctuating pressure coefficient on the rear surface increases from approximately 40 to 70 through nonlinear shear layer instability amplification. In contrast, V* has a negligible influence on the conditionally averaged pressure (∼10% variation) but amplifies the global fluctuation intensity by approximately 80% at V* = 0.030 relative to V* = 0.010 via added mass and pumping effects. Three distinct vortex regimes are identified with increasing P*: advection-dominated transport with fragmented vortices (P* = 0.2), vortex-pair-dominated transport (P* = 0.6), and multivortex entrainment with reverse transport (P* = 1.0). Virtual tracer analysis quantifies this transition as the residence time distribution shifts from a broad bimodal distribution to a sharp unimodal distribution. The resolved viscous dissipation rate increases superlinearly with P*, with the peak value rising from 0.004 at P* = 0.2 to 0.025 at P* = 1.0, exceeding a fivefold increase, driven by strain rate self-amplification. A four-stage energy cascade pathway is identified: jet acceleration, turbulent diffusion, vortex roll-up with scale transfer, and dissipation at the vortex edges. Spectral proper orthogonal decomposition reveals that increasing P* sharpens Kelvin–Helmholtz fundamental modes and intensifies second-harmonic modes, whereas increasing V* fragments higher-harmonic coherence through beat frequency interference.