Numerical Simulation Study of Dredger Impeller Based on Fluid-Solid Coupling

Aims: The majority of current research on submerged impellers concentrates on transient hydrodynamic properties; however, the modifications to the flow field and impeller caused by fluid-solid interaction have not been sufficiently studied.

Study Design: The vibration and deformation of the impeller due to the flow field's changing flow velocity will have an impact on the impeller's stability.

Methodology: In this study, two-way fluid-structure coupling is used to investigate variations in impeller dynamic stress as well as changes in the flow field's properties at various inlet velocities.

Results: The larger the flow velocity, the smaller the impeller's final deformation is, and the difference between the deformation at various flow velocities is approximately. 2%. The analysis and comparison of the maximum equivalent force diagrams at various velocities reveals that the maximum equivalent force in the impeller increases from 4.0615 MPa to 62.323 MPa with an increase in the flow velocity, exhibiting a jump growth. The maximum stress occurs at the beginning of the impeller's movement and reaches a maximum of 173.17 MPa. The maximum stress decreases with increasing flow field inlet velocity, falling to 168.65 MPa and 159.37 MPa at 2m/s and 3m/s, respectively.

Conclusion: The results based on the two-phase flow model and k-turbulence model demonstrate that the impeller deformation increases stepwise from inside to outside, and the total deformation of the impeller decreases as the flow field's inlet velocity increases. The maximum stress of the impeller first appears at the junction of the hub and the fan blade, where the stress decreases with the increase of flow velocity, and the maximum stress appears in the middle of the impeller.