Effects of Pitching Motion on Shock Behavior in a Body-Wrap Around Fin Configuration

The unsteady aerodynamic behavior of ttcp model with various wrap around fin sets were investigated in a trisonic wind tunnel. the aerodynamic coefficient force measurement in this wind tunnel shows good agreement in comparison with that of the nasa langley research center in static case.the model was sinusoidally oscillated at three different frequencies of 1,3 and 8 hz at m=2.0 and the effects of these frequencies on the shock angle were investigated and compared with the corresponding static case. experimental data indicate that the static shock angle does not fall between the upstroke and down stroke dynamic shock angle at different frequencies which is different from experimental findings for flat fin configurations. this unsteady behavior could be added to the other anomalies frequently seen in the aerodynamic characteristics of the wrap around fin conigurations. also,the shock development mechanism over the nose and several fin sets was investigated and the shock-boundary layer interaction near the fin/body juncture which leads to shock likes was clearly observed in this investigation