Investigation of Helicopter Ditching Angle on Fuselage Pressure Load using a SPH Method

Abstract

The water ditching characteristics of a three-dimensional helicopter model with various ditching angles are numerically investigated by using an in-house smoothed particle hydrodynamics (SPH) solver which solves the Navier-Stokes equations and six degree-of-freedom in a coupled way. Validation is performed on two-dimensional wedge water entry problem, where good agreement is achieved via comparing with documented experimental results. The ditching events of a complex helicopter model with both vertical and forward speed are simulated by the SPH method. The results indicate helicopter would suffer a more violent impact with a lower initial incident angle and a low pressure region creates rear suctions which will pitch up the helicopter when the suctions are strong enough.