Search NASA⌕ Search

Engineering topics

de la Llave, Rafael

Publications and source records attributed to de la Llave, Rafael.

Investigations of Relations Between Jupiter-Europa and Jupiter-Ganymede Resonant Tori in the Planar Bicircular Restricted 4-Body Problem

Most unstable periodic orbits of the planar circular restricted 3-body problem (PCRTBP) persist as invariant tori when a periodic forcing is added to the equations of motion. Among the persisting orbits are unstable resonant periodic or- bits. In this study, we first compute invariant tori in the planar concentric cir- cular restricted 4-body problem corresponding to exterior Jupiter-Europa and in- terior Jupiter-Ganymede PCRTBP resonant periodic orbits. Motivated by the 2:1 Laplace resonance between the orbits of Europa and Ganymede around Jupiter, we then use the computed tori to characterize relations between m:n Jupiter-Ganymede and m:2n Jupiter-Europa PCRTBP resonant orbits.

de la Llave, Rafael↗

Computation and Analysis of Jupiter-Europa and Jupiter-Ganymede Resonant Orbits in the Planar Concentric Circular Restricted 4-body Problem

Many unstable periodic orbits of the planar circular restricted 3-body problem (PCRTBP) persist as invariant tori when a periodic forcing is added to the equa- tions of motion. In this study, we compute tori corresponding to exterior Jupiter- Europa and interior Jupiter-Ganymede PCRTBP resonant periodic orbits in a con- centric circular restricted 4-body problem (CCR4BP). Motivated by the 2:1 Laplace resonance between Europa and Ganymede’s orbits, we then attempt the continu- ation of a Jupiter-Europa 3:4 resonant orbit from the CCR4BP into the Jupiter- Ganymede PCRTBP. We strongly believe that the resulting dynamical object is a KAM torus lying near but not on the 3:2 Jupiter-Ganymede resonance.

Gunter, Brian↗

Using GPUs and the Parameterization Method for Rapid Search and Refinement of Connections between Tori in Periodically Perturbed Planar Circular Restricted 3-Body Problems

When the planar circular restricted 3-body problem is periodically perturbed, most unstable periodic orbits become invariant tori. However, 2D Poincare ́ sections no longer work to find their manifolds’ intersections; new methods are needed. In this study, we first review a method of restricting the intersection search to only certain manifold subsets. We then implement this search using Julia and OpenCL, representing the manifolds as triangular meshes and gaining a 30x speedup using GPUs. We finally show how to use manifold parametrizations to refine the ap- proximate connections found in the mesh search. We demonstrate the tools on the planar elliptic RTBP.

de la Llave, Rafael↗

Rapid and Accurate Computation of Invariant Tori, Manifolds, and Connections Near Mean Motion Resonances in the Periodically Perturbed Planar Circular Restricted 3-Body Problem Models

When the planar circular restricted 3-body problem (RTBP) is periodically perturbed, most unstable resonant periodic orbits become invariant tori. In this study, we 1) develop a quasi-Newton method which simultaneously solves for the tori and their center, stable, and unstable directions; 2) implement continuation by both perturbation as well as rotation numbers; 3) compute Fourier-Taylor parameterizations of the stable and unstable manifolds; 4) globalize these manifolds; 5) compute homoclinic and heteroclinic connections. Our methodology improves on efficiency and accuracy compared to prior studies, and applies to a variety of periodic perturbations. We demonstrate the tools on the planar elliptic RTBP.

de la Llave, Rafael↗