Fluid-structure interaction of parachute suspension lines using LS-DYNA's incompressible computational fluid dynamics solver

Parachute Suspension line fluid-structure interactions (FSI) commonly result in performance degradation and noise generation that can be heard for several kilometers. Valuable insight into future suspension line designs can be derived from computational models that capture the key unsteady and vortical nature of the flow, while allowing the adjustment of structural parameters within the design envelope. A spring-mass-damper structural model is strongly coupled to the LS-DYNA incompressible computational fluid dynamic (ICFD), two-dimensional (2D) unsteady, Navier-Stokes solver to capture the suspension line response to prescribed parameters of interest. In the current research, a parametric study is completed to identify a computational fluid dynamics (CFD) model that is a good compromise between mesh density and computational efficiency for the subsequent integration of a structural model for completing 2D FSI investigations of a suspension line in a flow field. Three different surface topologies and multiple forcing frequencies were analyzed using the LS-DYNA ICFD solver. The resulting motions show qualitative agreement with wind tunnel observations in terms of motion shape and direction. The FSI modeling approach shows promise for future models that can guide changes in the design of parachute suspension lines to mitigate the compromising vibrations.