Research On Collaborative Optimization Design For Tail Fins Of A Testing Rocket Based On Aerodynamic And Structural Analysis

Tail fins are the key components which provide lift force and guarantee the flight stability of the testing rocket. The design of tail fins is a typical multidisciplinary optimization problem, which involves multiple disciplines such as aerodynamics, structure, strength, etc. Tail fins must meet the requirements of aerodynamics, strength, stiffness, light weight and so on. Based on the division of the disciplines, conventional design depends on manual iteration by serial mode, thus it is difficult to achieve the elaborate design with the coupled factors between various disciplines taken into account. Hence, the design process is time-consuming and the design quality is non-optimal.To overcome the above problem, the multidisciplinary collaborative design principle was introduced into the design of tail fins in this dissertation. By establishing an aerodynamic-structural collaborative optimization model for tail fin of a testing rocket, a collaborative optimization design method was employed to improve the design quality and to reduce the design backtracking. The main contents of this study are as follows:(1) Research on the preconditions for tail fins design. Systematic requirements of the flight stability were decomposed, and then the relationship between flight stability and design parameters of tail fins was studied. The mathematical model was established, which reflected the relationship among the static stability margin, the center of mass and pressure. The flight profile of a testing rocket was studied. The flight trajectory characteristics of a testing rocket were analyzed and the most severe flight environments as the design preconditions of tail fins were obtained by the trajectory simulation.(2) Research on aerodynamic design of tail fins. Aerodynamic characteristics of testing rocket were analyzed theoretically. Based on the static stability margin and other aerodynamic characteristics, the preliminarily aerodynamic configuration and parameters of tail fin were designed. The main aerodynamic characteristics of the central pressure coefficient, the lift coefficient and the drag coefficient were calculated while the Mach number changed from0.2to6.0and the angle of attack changed from-2°to10°, respectively. Also, the influence of tail fin parameters on the main aerodynamic characteristics was analyzed.(3) Research on structural strength and stiffness of tail fins. The structural strength and stiffness of tail fin under aerodynamic loads were analyzed by using plate theory and FEM based on APDL of ANSYS. Structural stress and displacement fields of tail fin were obtained. It was revealed that the results agree with each other with the deviation less than5%. (4) Research on aerodynamic-structural collaborative optimization design of tail fin. Based on the collaborative optimization principle, the aerodynamic-structural collaborative optimization model for tail fin was established. Moreover, the collaborative optimization architecture of tail fin was built via integrating Missile DATCOM and ANSYS into Isight.(5) Finally, a typical tail fin was designed as a verification demonstration. It was found that the aerodynamic area of single panel is reduced by52%and the structural mass is reduced by48%compared with the initial design parameters of tail fin, which shows the effectiveness of the present method.