Research on Design and Process Program for Grid Fin of Reusable Rocket

Grid fin aerodynamic control mechanism is one of the reusable rocket’s key parts. The design and manufacturing of grid fin is rather complex that coupling multi-specialty and multi-link. Aimed at the requirements of the reusable rocket, key design parameters of grid fins and their influences are presented combined with the grid fin’s geometric features from the aspects of working principle, geometric features, section shape, forward and backward sweep, etc.. Considering the thin-wall complex features of lattice and the requirements of high temperature resistance, several kinds of technological schemes and process program of titanium alloy forming and composite molding which can be used in the manufacturing of grid rudder are studied. From the aspects of design difficulty, process difficulty, product qualification rate, product accuracy and cost constrains, a comparative analysis of the process programs are made. Finally, the principles of grid fin design are proposed, providing a reference for the design of the Long March-8R（CZ-8R） rocket and other reused rockets.