Anomalies in the Flow over Projectile with Wrap-around Fins

Abstract

This paper presents the results of a numerical study to understand the flow field over a projectile with wraparound
fins. This investigation is performed in order to determine aerodynamic coefficients for the missile model for varying Mach number from 1.2 to 2.5. The roll moment coefficients were computed from the flow field solution and compared with other computational models and experimental works. The results show a reversal of the rolling moment in a Mach number from 1.2 to 1.4. While generating Mach number profile along missile body, a transition from subsonic to supersonic flow was notably found just before the fin-tip in the Mach number range from 1.2 to 1.4. This transition from subsonic to supersonic just before the fin seems to be the main cause for the roll reversal, which makes the flow inside the fin passage behave differently. Furthermore, it was seen that most of the effect was confined towards the leading edge of the fins.

Defence Science Journal, 2009, 59(5), pp.471-484, DOI:http://dx.doi.org/10.14429/dsj.59.1546