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Fluid-Structure Interaction Modeling of the Reefed Stages of the Orion Spacecraft Main Parachutes

Boswell, Cody W
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
28.11%
Spacecraft parachutes are typically used in multiple stages, starting with a "reefed" stage where a cable along the parachute skirt constrains the diameter to be less than the diameter in the subsequent stage. After a certain period of time during the descent, the cable is cut and the parachute "disreefs" (i.e. expands) to the next stage. Computing the parachute shape at the reefed stage and fluid–-structure interaction (FSI) modeling during the disreefing involve computational challenges beyond those we have in FSI modeling of fully-open spacecraft parachutes. These additional challenges are created by the increased geometric complexities and by the rapid changes in the parachute geometry. The computational challenges are further increased because of the added geometric porosity of the latest design, where the "windows" created by the removal of panels and the wider gaps created by the removal of sails compound the geometric and flow complexity. Orion spacecraft main parachutes will have three stages, with computation of the Stage 1 shape and FSI modeling of disreefing from Stage 1 to Stage 2 being the most challenging. We present the special modeling techniques we devised to address the computational challenges and the results from the computations carried out. We also present the methods we devised to calculate for a parachute gore the radius of curvature in the circumferential direction. The curvature values are intended for quick and simple engineering analysis in estimating the structural stresses.

Fluid–Structure Interaction Modeling of the Orion Spacecraft Drogue Parachutes

Kolesar, Ryan
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
18%
At higher altitudes, prior to the deployment of the main parachutes, the Orion spacecraft descent to Earth will rely on deceleration by drogue parachutes. These parachutes have a ribbon construction, and in fluid–structure interaction (FSI) modeling this creates geometric and flow complexities comparable to those encountered in FSI modeling of the main parachutes, which have a ringsail construction. The drogue parachutes to be used with the Orion spacecraft have 24 gores, with 52 ribbons in each gore, resulting in hundreds of gaps that the flow goes through. We address this computational challenge, as was done for the main parachutes, with the Homogenized Modeling of Geometric Porosity (HMGP). Like the main parachutes, the drogue parachutes will be used in multiple stages, starting with a "reefed" stage where a cable along the parachute skirt constrains the diameter to be less than the diameter in the subsequent stage. After a certain period of time during the descent, the cable is cut and the parachute "disreefs" (i.e. expands) to the next stage. Computing the parachute shape at the reefed stage and FSI modeling during the disreefing involve computational challenges beyond those in FSI modeling of fully-open drogue parachutes. Orion spacecraft drogue parachutes will have three stages...

Fluid-Structure Interaction Modeling of Parachutes with Disreefing and Modified Geometric Porosity and Separation Aerodynamics of a Cover Jettisoned to the Spacecraft Wake

Fritze, Matt
Fonte: Universidade Rice Publicador: Universidade Rice
Relevância na Pesquisa
48.13%
Fluid--structure interaction (FSI) modeling of spacecraft parachutes involves a number of computational challenges. The canopy complexity created by the hundreds of gaps and slits and design-related modification of that geometric porosity by removal of some of the sails and panels are among the formidable challenges. Disreefing from one stage to another when the parachute is used in multiple stages is another formidable challenge. This thesis addresses the computational challenges involved in disreefing of spacecraft parachutes and fully-open and reefed stages of the parachutes with modified geometric porosity. The special techniques developed to address these challenges are described and the FSI computations are be reported. The thesis also addresses the modeling and computation challenges involved in very early stages, where the sudden separation of a cover jettisoned to the spacecraft wake needs to be modeled. Higher-order temporal representations used in modeling the separation motion are described, and the computed separation and wake-induced forces acting on the cover are reported.