The Effect of the Geometric Parameters of the Fin on Aerodynamic Performance of Missile.

In the aerodynamic design of missiles, it is necessary to consider a wide design space. The complexity of a design space depends on the number of input variables. Missile diameter, nozzle, body length, the number of rows of fin, the number of fins for each row, the size and shape of each ffin, and their cross-section can be provided as examples of design variables. In this study, the aerodynamic characteristics of drag force , lift force, rotational torque, maneuverability, lift-drag force ratio as well as compressive force at Mach numbers and different attack angles were investigated. The results showed that aerodynamic coefficients increased with the addition of a fin in front of the missile. It is also observed that the stability of the missile improves when the fin is near the end of the missile but the ratio of lift to drag and maneuverability is reduced. It was also found that by increasing the length and height of the fin lifting force to the drag force, vertical force and the stability of missile increases. Also, it was observed that lift-drag force ratio increases with the increase in the number of fin rows.