Numerical simulation of cavity evolution and motion characteristics of double hollow cylinders in oblique water entry

The study of structures entering water has long been a focal point in various scientific fields. This research investigates the behavior of double hollow cylinders during water entry. Initially, the cavity formation of a single hollow cylinder is studied using the improved Detached Eddy Simulation (IDDES) method. Subsequently, the effects of varying distances and velocities on the motion and cavity development of two hollow cylinders are examined. Results reveal that, in contrast to a single hollow cylinder, the interaction between the two cylinders introduces mutual interference. However, the first cylinder (hollow cylinder 1) experiences minimal impact from this interference. Notably, the splash jet generated by hollow cylinder 1 strikes hollow cylinder 2, generating a torque (My2) on cylinder 2. As the distance between the cylinders decreases and velocity increases, this torque alters the inclination angle of cylinder 2, significantly affecting its stability and increasing the risk of collision. These findings contribute to the understanding of double hollow cylinders in water entry scenarios, offering valuable insights for practical engineering applications.