Incorporation of Gap Effects in the Design of High Performance Missile Control Fins

Nielsen Engineering & Research (NEAR) proposes to develop a new missile control fin design method to maximize fin normal force, minimize actuator requirements, and control fin wake. Current design methods do not adequately model fin-body gap effects. CFD technology will be employed to provide insight in gap flow details. Ultimately, the CFD findings will be included in the NEAR OPTFIN control fin design method. In Phase I, the OPTFIN aerodynamic modules and other missile aerodynamics codes will be applied to control fin data to define predictive deficiencies; concurrently, the OVERFLOW CFD code will be employed to analyze the gap flows and to generate fin load predictions for comparison with the data. An unconventional fin planform will be designed with enhanced OPTFIN and analyzed with OVERFLOW. In Phase I Option, unconventional control fin-body concepts will be designed and analyzed with CFD for consideration in Phase II. During Phase II, alternative CFD gridding and turbulence modeling issues will be addressed in order to generate the best gap flow solutions. Promising designs will be tested in the wind tunnel. The Phase II deliverables will include a control fin design code including detailed fin gap effects.