Analysis of Free Fright Model-Airplane with Sudden Loss of the Vertical Tail by Single Video Camera Method

Abstract

The method to measure aerodynamic forces and moments acting on a flight body in unsteady motion by a single video camera, which we have been developing, was used for the research. The location and posture of the flight body was derived by the correlation method, which is similar to that of the particle tracking velocimetry with the consideration of the flight body rotation. This method was applied to a free flight radio-controlled airplane in a low speed wind tunnel. The vertical tail wing of the airplane was suddenly removed during the steady level flight condition. After calculating the location and posture of the airplane by the single video camera method, the results were approximated by polynomials or filtered out to get the reasonable aerodynamic forces and moments without an unfavorable oscillation. Furthermore, the resultant data were converted to those of the body coordinates. The beginning of a Dutch roll motion was analyzed by the method and the aerodynamic forces and moments corresponding to the motion were investigated. After a while from the vertical tail wing loss, rolling and yawing moments had a rapid increase correlatively.