CFD Study on a Pitching Missile with Respect to Reduce the Phantom Yaw Effect

This numerical study is about the alleviation of the Phantom Yaw Effect on a pitching missile. A pair of slit shaped side jets, so called aerostrakes is used to force a symmetric separation at the shoulder of the missile. The unsteady Reynolds averaged Navier-Stokes equations are solved with a two equation turbulence model for a case with and without aerostrakes. The missile is pitching sinusoidally at a frequency of 5Hz between 0 degrees <= alpha <= 44 degrees at Mach 0.8. The results show that the magnitude of the side force, resulting from Phantom Yaw, is reduced by the aerostrakes and the onset angle for the PYE is shifted to higher angle of attack. A reversal of sign of both the side force and yawing moment is also prevented when using the aerostrakes. Furthermore, the influence of the pitching motion on the relevant aerodynamic coefficients is less profound in the case with aerostrakes.