| Based on computational fluid dynamics,this paper analyzes aerodynamic characteristics of non-parachute terminal sensitive projectile(TSP)to investigate how the wings’ structure parameters affect the aerodynamic characteristics.Then the structure parameters are optimum designd to obtain the best terminal sensitive projectile shape.The wings structure affects the aerodynamic characteristics of two-wing non-parachute TSP,considering that the thin wings could deflect when it’s impacted by aerodynamic force,this paper established flexure models of three kinds of wings.The wings’ deflections are theoretically calculated based on reciprocal theorem and simulated based on two-way fluid-structure interaction.The aerodynamic characteristics of rigid-wing TSP and elastic TSP are compared and confirmed by free flight tests.The wings’ structure is optimized and the optimum structure of TSP’s wings is obtained.Restricted by analysis methods,the predecessors regarded the wing as a rigid one when analyzing the aerodynamic characteristics of TSP.This paper established the TSA aeroelastic model and simulated the aerodynamic characteristics of TSP with elastic wings.The TSP with rigid wings was also simulated to compare with the TSP with elastic wings.The free flight tests were carried out which showed that the drag coefficient and moment coefficient of TSP with elastic wings are closer to the experimental values whose maximum error are respectively less than 7.8%and 6%.The drag coefficients,lift coefficients and moment coefficient of TSP with rigid wings are about 20%,20%and 12%larger than those of TSP with elastic wings.The bending angles affect the aerodynamic characteristics of TSP the most while the area ratio and length-width ratio affected the least.Based on reciprocal theory,this paper theoretically calculated the deflection of TSP’s wings.By establishing the deflection model of three kinds of wing structure and setting up reasonable boundary conditions,the deflection equations were deduced by which the deformations of plate wing,S-style wing and C-style wing could be calculated.Two-way fluid-structure interaction was carried out to simulate how wings deformed by structure parameters.Then how attack angles and incoming velocities affected the aerodynamic parameters and windward pressure is analyzed.In order to obtain the TSP optimal aerodynamic shape,this paper optimized the wings structure of S-S TSP and S-C TSP based on orthogonal test method.The primary relation of wing parameters affecting the aerodynamic characteristics was deeply analyzed and the optimal structure of TSP was obtained.Free flight tests were carried out to verify the simulation results which showed that the drag coefficient and moment coefficient of both TSP increased obviously.The optimization methods and results could provide technical reference for the structure design of the non-parachute TSP. |
