Inflation analysis of ram air inflated gliding parachutes

This paper discusses two approaches for the analysis of the inflation of ram air inflated gliding parachutes. In one method the point mass equations of motion are solved with time-varying Lift and drag areas. This approach requires experimental data in order to construct the appropriate lift and drag area curves. The approach appears useful in analyzing parachute systems which are similar to systems for which data are available. On the other hand. the predictive accuracy of this approach is questionable for parachute systems which differ significantly from those for which data are available. The second method involves the finite element solution of the 3D equations of motion for the unsteady fluid dynamics equations around a falling, expanding box which models the inflating canopy. This technique can be used to model conceptual parachute designs for which no empirical data is available. These solutions require sophisticated numerical techniques and a high-performance computing platform and are not suitable for repetitive design studies and trade-off analyses. Our strategy will be to combine the two approaches by using the numerical solutions to generate lift and drag data and to incorporate these data in the flight mechanics simulations. The 3D solution of the flow field equations can be regarded as a numerical experiment in which the data generated can be used in simple flight mechanics simulations.