Abstract
In order to optimize the geometry of the missile’s cross-section for transportation purposes and also to obtain higher aerodynamic efficiencies, non-circular bodies have gained substantial attention by many researchers. In this work, we have compared the aerodynamic characteristics of three missiles having the same cross sectional areas, but different shapes (one circular , one square with round corners and one hexagonal with round corners). In order to differentiate the non-circularity and the fin effects, we have considered the bodies with no fins. A three dimensional, compressible, stationary, viscous, turbulent flow has been simulated using the FLUENT CFD code with the standard k-ε model. Our results indicate that, even though the square section missile has more friction drag, it produces less overall drag , similarly the hexagonal section has more frictional drag than square model , it produces less overall drag compared to both the square and circular section. Also, its lift is higher than that of the circular and square case and thus has a higher aerodynamic efficiency. Moreover, the rate of increase of the aerodynamic efficiency with increasing of the angle of attack is higher than that of circular and square section.