No abstract

A wind tunnel test is designed to study aerodynamic effects of one individual rocket with deflectable nose. The test measures pressure with U-bend tube which is cost effective. Using rubber tubes in different lengths to measure pressure distributions of a flat-plate, and calculating how rubber tube affects the measurement, in order to modify the measured surface pressure of the nose. The surface pressure varies on different points while yawing angle and attack angle changes, the changing regularity could provide data for following numerical simulation and trajectory control.

The basic experiment and detailed simulations are carried out to study the aerodynamic characteristics of projectile with deflectable nose. The parameters of computation are revised on the basis of experimental data. Further simulations show that the influence of mach number and deflectable angle on drag, lift, pitching moment and flight trajectory. The drag coefficient increases firstly and then decreases with the change of mach number, while drag coefficient and pitching moment coefficient grows exponentially. It can be seen that the ratio of lift to drag increases consistently, which means the aerodynamic efficiency of projectile would be improved with the increase of deflectable angle and mach number. The range is influenced by the start time of deflection. For the projectile with deflectable angle 10, the maximum range can be obtained if the forehead deflects at 3s.

Initiation style can affect detonation wave, with which the movement and shape of rod is controlled deeply. The driving characteristic of discrete rod is investigated numerically by finite element code. Four initiation styles are chosen to analyze the driving rule of the shape and velocity of discrete rod. According to those investigating results, side one-point initiation is the optimal style. In this condition, higher velocity and lower velocity margin are obtained, as well. Compared with other initiation styles, side one-point initiation can improve the damage ability about 10% for the certain requirement.

The damage characteristics of the steel-Kevlar-steel structure are studied by nonlinear dynamics software. The whole destruction process of the sandwich structure is simulated. Moreover, the transmission and reflection of the shock wave in the structure are analyzed. It shows that the damage zone of the structure is just under the explosive. It is significantly different from the damage under non-contact explosion. The composite material has an effect on the spread of the shock wave, and effectively reduces the peak pressure. The sandwich structure has a good anti-impact performance. The results help to design and assess blast-resistant structures under contact explosion.