0000000000021422
AUTHOR
Tapan Chandra Adhyapak
showing 3 related works from this author
Nonlinear electrostatic oscillations in a cold magnetized electron-positron plasma
2017
We study the spatio-temporal evolution of the nonlinear electrostatic oscillations in a cold magnetized electron-positron (e-p) plasma using both analytics and simulations. Using a perturbative method we demonstrate that the nonlinear solutions change significantly when a pure electrostatic mode is excited at the linear level instead of a mixed upper-hybrid and zero-frequency mode that is considered in a recent study. The pure electrostatic oscillations undergo phase mixing nonlinearly. However, the presence of the magnetic field significantly delays the phase-mixing compared to that observed in the corresponding unmagnetized plasma. Using 1D PIC simulations we then analyze the damping of t…
Ewald sum for hydrodynamic interactions of rigid spherical microswimmers
2018
We derive the Ewald sum decomposition of the grand mobility tensor which captures the hydrodynamic interactions in an infinite suspension of rigid spherical microswimmers. The grand mobility tensor connects the motion of an individual swimmer to the active and passive forces and torques acting on all the swimmers, and it is calculated based on a minimal microswimmer model incorporating the swimmers' finite body size. Our results have direct applications to the Stokesian dynamics simulations of an infinite suspension of rigid-bodied microswimmers. They also provide a platform to develop more advanced methods such as particle-mesh-Ewald-sum and accelerated Stokesian dynamics simulations.
Flow properties and hydrodynamic interactions of rigid spherical microswimmers.
2017
We analyze a minimal model for a rigid spherical microswimmer and explore the consequences of its extended surface on the interplay between its self-propulsion and flow properties. The model is the first order representation of microswimmers, such as bacteria and algae, with rigid bodies and flexible propelling appendages. The flow field of such a microswimmer at finite distances significantly differs from that of a point-force (Stokeslet) dipole. For a suspension of microswimmers, we derive the grand mobility matrix that connects the motion of an individual swimmer to the active and passive forces and torques acting on all the swimmers. Our investigation of the mobility tensors reveals tha…