Aerodynamic Interference And Numerical Simulation Of Fluid-structure Interaction Of UAV Missile Launching

UAV carry out diverse tasks have become increasingly demanding in modern warfare.In an attack mission, the UAV will launch missiles or drop bombs, this phenomenon withinthe scope of the problem of multi-body separation. Because in the initial stages of separationthere is a significant aerodynamic interference between carrier aircraft and isolates, especiallythe tail jet of missile will take more serious impact on the pneumatic of carrier aircraft whenfired missiles, resulting carrier aircraft have great flight instability at this time. Therefore,when we analysis the UAV mounted and fired missiles, the mechanism and impact ofpneumatic interference problems between carrier aircraft and missiles at the moment ofseparation has a certain practical significance to the safe flight of UAV and safe separation ofmissile. This paper focuses on the analysis of missiles tail jet influence on the aerodynamicperformance of the carrier aircraft’s airfoil when the UAV launch missiles, in the same time,we also analysis the stress and strain level of the airfoil’s agency by the aerodynamic.In this paper, we use the method of fluid-structure interaction. At the first, we achievethe simulation of real process in fluid calculation module by establishing a simplified model,setting smooth domain type, boundary conditions and motion parameters. During thesimulation, we use six degrees of freedom coupled equation to achieve the numericalsimulation for the separation process when the UAV launch missiles. This paper intends touse CFD technology to solve the movement of objects unsteady flow field to get real-timeaerodynamic data, we can use the data to achieve flight dynamics simulation. By usingcalculation method of applicable moving boundary of dynamic unstructured grid and unsteadyflow field, coupled external weapons rigid six degrees of freedom kinematics, dynamicsequations, solving the external weapons trajectory and attitude. Meanwhile unsteady flowfield gives real-time UAV aerodynamic, and the time course unsteady aerodynamic disturbance force by the external weapons separation brought. Then the fluid load couple to asolid structural mechanical analysis part, in this analysis we use ANSYS software kineticanalysis, the various loads which calculated before are loaded to the wing structure, thecomputer simulation of the wing by a variety of loads when the impact of stress distributionand strain variations.Through simulation results aware, the tail jets of the initial stage of the missile launchedhave greatly changed the structure of the flow field around the wing, also have a significanteffect on the aerodynamic performance of the airfoil of UAV, there is a great instabilityinterference for the pre-flight missiles. By coupling calculations we can see because theweight of the plug and aerodynamic flow field around the airfoil, the airfoil will producedifferent degrees of chatter and reversed.