Numerical study of the effect of random longitudinal spacing on the flow field effect of unit reef

The spacing design of artificial reef (AR) deployments is crucial for optimizing the flow field effect of unit reef (UR). However, achieving ideal equal spacing for UR deployment poses significant challenges in practical engineering applications. When unexpected variations occur in the spacing between different ARs, the resulting impact on the flow field effect of UR remains uncertain. To address this issue, this study first validated the numerical simulation method using Particle Image Velocimetry (PIV) experiments, showing strong agreement between numerical and experimental results. Using a cubic reef as the target model, random combinations of relative spacings between three ARs were analyzed. The influence of relative spacing variations on the flow field effect of UR was investigated through correlation analysis. The results demonstrate that variations in the upstream and downstream spacings of UR can significantly affect the upwelling effect. The upstream spacing had a notable impact on the wake effect, while downstream spacing exhibited no significant influence on it. This study provides a deeper understanding of the internal flow field structure within UR and offers scientific guidance for the planning and placement of UR deployments.