Multi-disciplinary multi-objective design optimization of sounding rocket fins

Abstract

In this study we carry out multi-disciplinary multi-objective optimization of a solid fin for sounding rocket by considering its (i) aerodynamic performance in terms of static aerodynamic stability and drag, (ii) structural performance in terms of torsional deflection and factor of safety (FOS), and (iii) flight performance in terms of peak altitude (PA) and maximum payload capability for given propulsion system characteristics. Four different fin design optimization problems have been studied:(i) maximize PA of the sounding rocket and maximize aerodynamic static margin, (ii) maximize PA and maximize payload mass, (iii) maximize PA and minimize tip torsion angle of the fin, (iv) maximize PA and maximize FOS. In all of these optimization problems, essential aerodynamic and structural constraints have been satisfied. Multi-objective optimization has been used to get the Pareto-optimal front of the conflicting objectives. It is seen that all the four design problems have conflicting objectives. The study gives insight into the optimal fin configuration variables and effect of active constraints.