Control of Hinge Moment by Tailoring Fin Structure and Planform

Nielsen Engineering & Research (NEAR) proposes to employ its updated flexible fin and fin planform optimization technologies to control/minimize missile fin hinge moments while maintaining normal force required for high g maneuvering. In the Phase I effort, sensitivity studies will be performed to determine which portions of a typical missile control fin are most effective to provide passive control of center of pressure location through local deformation. Suitable flexible fin structures with tailorable stiffness characteristics will be identified. Parametric studies will be performed to demonstrate the feasibility of passively controlling hinge moment subject to flutter, geometrics, and other constraints. In the Phase I Option, the technology will be applied to the redesign of existing control fins. In Phase II, the fin structural model and design optimization scheme will be extended to include piezo-electric elements for active control, and to incorporate effects of fin-body gap and planform shape. Trade-off studies will compare various passive and active profile control fins over realistic flight profiles. Flexible missile control fins will be designed and analyzed with CFD prior to systematic wind-tunnel testing. The resulting technology will provide advanced control fins capable of generating superior aerodynamic performance over the missile airframe flight profile.