Parametric stability of a double pendulum with variable length and with its center of mass in an elliptic orbit

<p style='text-indent:20px;'>We consider the planar double pendulum where its center of mass is attached in an elliptic orbit. We consider the case where the rods of the pendulum have variable length, varying according to the radius vector of the elliptic orbit. We make an Hamiltonian view of the problem, find four linearly stable equilibrium positions and construct the boundary curves of the stability/instability regions in the space of the parameters associated with the pendulum length and the eccentricity of the orbit.</p>

Counter- and co-directed swirling-type waves due to orbital excitations of a square-base tank

The analytic technique and numerical experiments are employed to show that the orbital elliptic translational ex citations of a square-base container can, depending on the ratio of the semiaxes of the elliptic orbit, lead, when the forcing frequency is close to the lowest natural sloshing frequency, to both the counter- and co-directed (relative to the orbital forcing direction) stable swirling-type steady-state resonant waves. For a non-zero damping in the hydrodynamic wavy system, the passage to circular orbits makes the stable counter-directed swirling impossible.

Composite Immersion and Invariance Based Adaptive Attitude Control of Asteroid-Orbiting Spacecraft in Elliptic Orbit

The authors have requested that this preprint be withdrawn due to author disagreement.

Morphology of gas flow during collision of accretion disks in a T Tauri type binary with elliptic orbit

Представлены результаты численного моделирования взаимодействия аккреционных дисков при прохождении периастра в двойной звезде типа Т Тельца с эллиптичной орбитой. Рассмотрена структура системы ударных волн в аккреционных дисках и между ними и ее изменение с течением времени. Обсуждается возможность построения аналитической модели взаимодействия аккреционных дисков. We present the results of numerical simulation of interacting accretion disks in a T Tauri type binary with elliptic orbit. Using these results we study structure and evolution of the system of shock waves in accretion disks and between them. Finally we discuss the possibility of bringing up an analytical model for accretion disk interaction.