Stability and Flying Qualities of an Unmanned Airplane Using the Vortex-Lattice Method

摘要

A vortex-lattice method was employed to compute the forces and moments acting on the airplane. These were used to compute stability derivatives. The longitudinal and lateral-directional derivates show that the airplane is statically stable.rnThe open loop longitudinal dynamic stability results show that, for the two modes of longitudinal motion of response, the short-period and phugoid, the reaction is an oscillatory mode describing sinusoidal motion with an amplitude that decreases exponentially with time.rnThe Dutch roll and roll modes of the airplane match with damped and convergent modes, respectively. However, the spiral mode response prediction corresponds to a divergent mode. This means the airplane is dynamically unstable for the spiral mode, and stable for Dutch roll and roll modes.