Effect Of Initial Pitching Angle On Helicopter Ditching Characteristics Using Smoothed-Particle-Hydrodynamics Method

The present Paper investigates the ditching characteristics of a helicopter model by means of an in-house-developed smoothed-particle-hydrodynamics solver coupled with a six degree-of-freedom motion equation. Verification and validation have confirmed the feasibility and accuracy of the developed solver in predicting hydrodynamic problems. In view of the inherent importance, the effect of initial pitching angle of helicopter was comprehensively considered. Numerical results show that the helicopter experiences a subsequent nose-up and nosedown motion for all the positive initial pitching angles during ditching which is caused by the hydrodynamic overpressure and suction effects. The initial pitching angle significantly affects the helicopter ditching characteristics in terms of load and pressure distribution. For the specific configuration of the helicopter, ditching with initial pitching angle at 6 or 8 deg endures relative lower hydrodynamic load in both horizontal and vertical directions, which can be regarded as preferable setups for a controllable ditching event.