The Study On Scanning Motion Of Two-wings Terminal Sensitive Projectile

This thesis presents a novel scheme of realizing stable scanning technology which uses two pieces of low aspect ratio wings on the basis of analysis of the advantages and disadvantages of the existing stable scanning technology of Parachute Terminal Sensitive Projectile. This method achieves stable scanning motion by using the spin resonance motion caused by asymmetry of the aerodynamic force. Combined with theoretical analysis, numerical and experimental study, the motion characteristics, aerodynamic characteristics and scanning movement stability of the Two-wings Terminal Sensitive Projectile have been studied systematically to supply a theoretical foundation and technical support for the design and improvement of Two-wings Terminal Sensitive Projectile.The main researchs of the thesis include:1) Research on the characteristic of Two-wings Terminal Sensitive Projectile stable scanning motion.Consider the Two-wings Terminal Sensitive Projectile is a system contained three rigid body wich are the projectile and two wings. Anylyzed the aerodynamic force and monent in the condition of high angle of attack and established the nonlinear motion model of the Two-wings Terminal Sensitive Projectile. Considering that the Two-wings Terminal Sensitive Projectile’s attitude changes great during free flight, quaternion method is used to process the motion model of Two-wings Terminal Sensitive Projectile, and standardized equations which are suitable for machine programmingare established, and computer programs of model are developed which give procedures example. Results show that the designed Two-wings Terminal Sensitive Projectile system can achieve stable scanning motion.2) Experimental study on the wing’s structure parameters effect on the stable scanning motion characteristic.Terminal Sensitive Projectile aerodynamic design principles are established on the basis of theoretical study, according to which the Two-wings Terminal Sensitive Projectile physical model is designed and the tower free flight tests are placed. Then the motion characteristics of flat-wing model, S-C wing model and S-S wing model are analyzed. Based on the experimental study, S-C wing and S-S wing Terminal Sensitive Projectile can achieve stable scanning motion while the flat-wing model can’t. Furthermore, the rules of area of wings effect on the motion characteristics were gotten. The drag coefficient increase with the area of the wings increasing and the moment coefficient have a little change with the area of the wings increasing. The experiment alse shows that with the increasing of the area of wings the moment increasing while the stability greatly decreased. According to the free flight experiment, the wing shape selection criteria of Two-wings Terminal Sensitive Projectile which is appropriate for stable scanning is determined.3) The study on the wing’s structure parameters effect on the aerodynamic characteristic Terminal Sensitive Projectile.Flow field and aerodynamic force of Two-wings Terminal Sensitive Projectile are numerically calculated by using Computational Fluid Dynamics method. We obtained the rules of surface pressure distribution and drag coefficient and lift coefficient and torque coefficient changes with angle of attack. Further anylized the aerodynamic characteristics of Two-wings Terminal Sensitive Projectile with different wingspan and chord. Results show that the increase of area of wings has significantly increase the drag coefficient, less about lift coefficient and torque coefficient. Through the study on the aerodynamic characteristics of S-S wing Terminal Sensitive Projectile with diffirent combination of wing angle found that wing angle is the main influencing factor on torque coefficient.4) Study on movement stability of non-parachute Terminal Sensitive Projectile.Base on plat wing Terminal Sensitive Projectile model, in theory systematic study on stability of the Two-wings Terminal Sensitive Projectile scanning motion. Considering the high angle of attack characteristics, anylize the forece and establish perturbation equations of motion. According to Singularity Theory, analysis of Two-wings Terminal Sensitive Projectile motion stability criteria. Clear a parametric representation of the movement stable range, clarifying the structure parameters on the Terminal Sensitive Projectile motion stability effects. The stability analysis of Two-wings Terminal Sensitive Projectile motion provide theoretical support for Two-wings Terminal Sensitive Projectile stable scanning platform design.