A prediction method for hydrodynamic load of seaplane with flow separation considered

During the early design phase of a seaplane, it is necessary to estimate the hydrodynamic load acting on the bottom structure of its fuselage. The flow separation is one of the important factors that makes it difficult to accurately analyse water load. The experimental or numerical methods often require a significant amount of time and cost, thus being difficult to meet the needs of the early design stage of the seaplane. Therefore, based on numerical and experimental analysis results, the liquid surface morphology after the wedge enters into water was simplified and approximated. A theoretical method was used to establish the relationship between the separation cavity angle and the inclined lift angle. The relationship was introduced into the semi-analytical method that considers the fictitious body continuation. The paper proposed a theoretical correction method for fast analysing the water entry slamming force after separation, which improved the ability to predict the slamming force in the early stage of separation at different inclined lift angles and water entry velocities.