Forebody Wake Efiects on the Aerodynamics of an Annular Parachute

摘要: Annular parachute designs potentially ofier the highest drag for hemispherical, nongliding geometries. A concentric double annulus design was recently studied by US Army to determine its performance and sensitivity operating conditions. This paper presents time-resolved time-averaged results from simulations using a ReynoldsAveraged Navier-Stokes ∞ow solver study efiects of forebody wake on aerodynamics at Reynolds numbers 8:03¢10 6 10:04¢10 . The system consists large diameter with ofiset below smaller annulus, payload represented ∞at disk. Previous annular geometry (McQuilling Potvin, Journal Aircraft, 49(2), 566-575, March-April 2012) highlighted transient nature around annuli without payload. Results indicate severe reduction in both speeds when 4ft disk is placed 25 feet upstream current geometry. found be caused vortex that diverts oncoming air away canopy mouth instead into sides.