수치기법을 이용한 헬리콥터 고공강하 시뮬레이션

다국어 초록 (Multilingual Abstract)

HALO/HAHO are methods of delivering personnel, equipment and supplies from a transport aircraft at a high altitude via free-fall parachute insertion. HALO(High Altitude-Low Opening) and HAHO(High Altitude-High Opening) are also known as Military Free Fall. In the HALO technique, the parachutist opens his parachute at a low altitude after free-falling for a period of time, while in the HAHO technique, the parachutist opens his parachute at a high altitude just a few seconds after jumping from the aircraft.
The HALO parachutist jumps from the helicopter at fast forward flight to avoid attack from the enemy. The trajectory of skydiving shows down/backward falling. The skydiver could be humped against external protuberance around aft fuselage of the helicopter at moment of jumping. The configuration design is needed to consider about crash skydiver against fuselage or the flight manual has to describe speed limitation during HALO. The helicopter pitch attitude of fuselage and downwash from rotor is become different by forward flight speed. In this paper, the helicopter attitude and the rotor blade motion were simulated by HOST(Helicopter Overall Simulation Tool) to use input data to CFD(Computational Fluid Dynamics) for HALO simulation. The rotor blade was modeled by actuator disk method and the interference analysis was performed including skydiver, fuselage and rotor downwash. The human body was modeled 95% height size and 5% weight of human database for conservative simulation. The analysis results of interference with skydiver and fuselage, drag coefficients by attitudes of diving, external forces of sky diver were inputted to equations of motion to calculate the diving trajectory. The forward flight speed was suggested from the trajectory simulation to avoid crash against with protuberance of helicopter.