Abstract: To explore the inflation performance and aerodynamic characteristics of vortex ring parachute which is often used as decelerating and spinning parachute of smart ammunition, the inflation process under the conditions of infinite mass and slow flow velocity is simulated using arbitrary Lagrange-Euler method. The canopy deforming process, time-history curves of spinning rate and projected diameter and fluid domain features at steady state are obtained. The finite model of inflated canopies is transformed to a simulation model of aerodynamic characteristics. The aerodynamic force parameters, the features of velocity streamlines and the pressure distribution are obtained by using computational fluid dynamics method. The results obtained by the two methods are compared and analyzed. The results show that the vortex ring parachute can inflate smoothly and rotateat 12 m/s. The shape of inflated canopy is plump and the steady spinning rate is about 3.3 r/s. The drag coefficient is about 1.36, which is greater than those of other typical parachutes with axial symmetry structure. The spinning moment coefficient is 0.87. The distributions of fluid domain features are centrally symmetrical around the parachute axis.

Key words: ordnance science and technology, vortex ring parachute, inflation, fluid-structure interaction, computational fluid dynamics, aerodynamic characteristics