Spatial temporal evolution characteristics of marine propeller wakes based on lattice Boltzmann method-large eddy simulation

In this paper, a high-fidelity numerical investigation of the wake characteristics and spatiotemporal evolution of a ten-blade small-scale propeller is comprehensively conducted using the lattice Boltzmann method-large eddy simulation. Numerical simulations are systematically performed to analyze the wake dynamics at four representative advance coefficients (J = 0.394, 0.591, 0.787, and 0.984). The tip vortex structures and spatiotemporal evolution behind the propeller are accurately visualized using the Q-criterion, while mean velocity profiles and vorticity distributions are clearly revealed through axial cross-sectional analyses. Based on vorticity patterns, the wake field is categorized into three distinct regions. The spatiotemporal evolution of vortex structures in stable, transitional, and unstable zones is statistically quantified across different advance ratios. Both the stable flow region and the transition region behind the propeller blade are progressively broadened with increasing advance coefficient. Velocity fluctuation statistics in near-, mid-, and far-field wake regions are quantitatively captured, and momentum characteristics are further analyzed via box-plot and power spectral density at monitored points. It is also observed that the nonlinear growth characteristics of stable tip vortices are gradually enhanced with increasing advance coefficient. Quantitative relationships are successfully established between the positions of tip vortex cores and vorticity distributions, as well as between vortex core spacing and advance coefficient. Furthermore, the average spacing between vortex cores is progressively widened, while vorticity distribution is correspondingly reduced as the advance coefficient increases. Complex propeller wake physics are accurately captured, providing new insights into the multiscale spatiotemporal evolution of propeller wakes under varying operational conditions. These findings offer fundamental references for propeller optimization and wake management strategies in marine engineering applications.