Ditching characteristics of a seaplane under various wave conditions and effects of biomimetic floats

Abstract

This paper presents a numerical investigation into the hydrodynamic loads and motions experienced by two seaplane models during ditching in calm water and regular waves. The original bare model is susceptible to jet flows and wave overwash at the nose, which can adversely impact the aircraft's ditching performance. To address these issues, we introduced two biomimetic floats symmetrically to the original model and assessed their influence on the ditching dynamics. A comparative analysis was conducted on the accelerations, impact loads, and the coupled heave and pitch motions of both the original and the redesigned model equipped with floats during ditching in both calm waters and regular waves. For the wave ditching scenario, a detailed investigation of the slamming phase was first carried out, involving impacts at the wave's zero-crossing, crest, and trough. The cases with a variety of wave heights, wave lengths, and wave headings were evaluated. A particular focus was placed on understanding how the biomimetic floats affect the seaplane's performance during ditching in both calm and wavy conditions. The analysis of maximum accelerations and pitch angles during wave ditching revealed that slamming at the wave trough presents the most significant hazards. Additionally, the phenomena of gliding and wave overwash were identified as substantial risks under wave conditions. The results suggested that the biomimetic floats can effectively mitigate the maximum horizontal acceleration and pitch angle of the original model, enhancing the safety of ditching operations in both calm water and waves.