Hydrodynamic performance of bionic streamlined remotely operated vehicle based on CFD and overlapping mesh technology

• The bionic streamlined geometric model obtained by parametric modeling using regular lines and NURBS curve interpolation is adopted. • The entity model shows greater hydrodynamic force in the translation motion at different drift angles and attack angles. • The vertical force and pitching moment of the square net model are obvious greater than that of the entity model under pure heave and pitching motion. • The static and dynamic stability coefficients of the square net model are greater than that of the entity model, and the maximum lift-to-drag ratio is obtained at 6∼8° attack angles. To meet the intelligent detection needs of underwater defects in large hydropower stations, the hydrodynamic performance of a bionic streamlined remotely operated vehicle containing a thruster protective net structure is numerically simulated via computational fluid dynamics and overlapping mesh technology. The results show that the entity model generates greater hydrodynamic force during steady motion, whereas the square net model experiences greater force and moment during unsteady motion. The lateral and vertical force coefficients of the entity model are 4.32 and 3.13 times greater than those of the square net model in the oblique towing test simulation. The square net model also offers better static and dynamic stability, with a 24.5% increase in dynamic stability, achieving the highest lift-to-drag ratio at attack angles of 6°∼8°. This research provides valuable insights for designing and controlling underwater defect detection vehicles for large hydropower stations.