Numerical Simulation of the Effect on External Store Separation in Helicopter Flow Field

In this paper, the CFD method is used to carry out the numerical study on the influence of the flight trajectory of the helicopter in hovering and small speed forward flight, and the research selects the Caradonna-Tung rotor and the related fuselage and external store model after the proportional amplification, and uses dynamic patched and overset grid technique. The control equation of the flow field of the helicopter, which include the Reynolds Averaged Navier-Stokes (RANS) equations and the motion equations of the rigid body six of degree of freedom, are solved by coupling. According to the change of the centroid displacement trajectory and the Euler angle (pitching angle, roll angle and yaw angle), the flight trajectory of the external store in different conditions is analyzed, and the influence of the helicopter’s flow field on the flight trajectory of the external store is studied. Through the analysis of the influence of the external store separation trajectory, the research shows that the external separation is influenced by the free flow, the helicopter wash flow and the self-gravity and the posture presents the characteristics of low head, negative rolling and forward yaw. The research work provides valuable reference to the safety problem for the launch and separation of missiles, and the airdrop of personnel and materials from the helicopters.