The Numerical Simulation Of Helicopter Airborne Air-to-air Missile Launch Flow Field

With the development of weapons and equipment updates,the armed helicopter plays more and more important role in modern war.Helicopter will produce complex downwash flow field around the fuselage when helicopter is working.The downwash flow field put forward severe test to the lunch of airborne missile.Thesudy of mutual influence between helicopter fuselage and air-to-air missile is more and more importance.In this paper,the reseach is on constructing three dimentional model of helicopter fuselage,main rotor and missile respectively which is based on armed helicopter structure size and consider properties of helicopter itself.Exploring the use of the grid-boltzmann method in CFD(Computational Fluid Dynamics),the dynamics change problem of airflow field lunched by airborne missile is solved while the helicopter main rotor is rotating.And the focus of that is on the model of helicopter,rotor waves and air-to-air missile.The paper is structured as followed:Firstly,different rotor downwash flow engineering estimation method is compared.With reference to messless technology,the downwash flow field around helicopter fuselage using CFD software Xflow which is based on grid-boltzmann algorithm has been simulated.Grid-boltzmann algorithm based on subject characteristics is studied,and its reliability is also verified.Moreover,the environment under helicopter flies is analyzed,the formation mechanism of downwash flow field is introduced when main rotor is rotating.With reference to messless technology,the downwash flow field around helicopter fuselage using CFD software Xflow which is based on grid-boltzmann algorithm has been simulated.The aerodynamic parameters changing law on missile tracjery which is lunched at different horizontal and vertical level has been stimulated,for offering the basis of next research on the downwash flow'influence of guided missile launching.Finally,the motion equation of airborne missile in the initial stage of 0.3s is definited.On the base of downwash flow field distribution data around helicopter fuselage which has been calculated,the airborne air-to-air missile launching process has been stimulated.Aerodynamic force and moment variation law of airborne missile generated by downwash flow at different horizontal and vertical level is calculated.Emulation results show that airborne missiles fly have influenced by downwash.