Magnus Effects on Stability of Wraparound-Finned Missiles

Wraparound fins are widely used as aerodynamic stabilizers for unguided missiles. Wraparound-finned configurations have more complicated flight dynamics when compared with configurations with planar fins. General linear free flight dynamic stability criteria of unguided missiles with wraparound fins are well known. However, until now simplified criteria that consider a static side moment due to wraparound fins as the only significant out-of-plane effect have been utilized in design. It is shown that the simplified stability criteria are not reliable, and more general stability criteria that take both the classical Magnus side moment and the static side moment due to wraparound fins into account have to be used. Another outcome is that the roll direction is extremely important in terms of stability of wraparound-finned configurations. A linear free flight dynamic stability analysis of the U.S. Air Force research model is performed as a case study by using available aeroballistic range test data.