Body-flexure control with smart actuation for hypervelocity missiles

An optimized hypervelocity missile with a body-flexure control is investigated in this paper. By taking the advantage of the structural flexibility of slender missiles, the present concept uses a body-flexure control with a smart structure (PZT) to effectively actuate the missile body in achieving instant bending through aeroelastic amplification in a given hypersonic/supersonic flight environment without any canard or bent-nose control. Two configurations were investigated including the missiles with planar fins and with wrap-around fins. The aerodynamic loads were computed using a high order aerodynamic panel code ZONAIR. Comparison between the present aerodynamic prediction and wind tunnel test at Mach numbers 3 and 6 are presented. The structural optimization for the skin composite structure with the piezoelectric (PZT) actuators was performed using ASTROS* code. A parametric study for the maximum maneuverability of the present configuration with respect to design uncertainties, such as the center of gravity locations, was investigated. The results show that the maximum achievable load factor of the PZT control is limited by the PZT material tensile stress; not the maximum voltage capacity. At M=6, the present body-flexure configuration with a maximum deflection angle of 2° is equivalent to that of a bent-nose control configuration with a nose deflection of 4°, and to that of canard control configuration with a canard deflection angle of 30°. In the full length paper, the drag coefficient of the present body-flexure configuration will be compared to that of bent-nose and canard control configurations.