Related papers: Transitions in the wake of a flapping foil
Hummingbirds and insects achieve outstanding flight performance by adapting their flapping motion to the flight requirements. Their wing kinematics can change from smooth flapping to highly dynamic waveforms, generating unsteady aerodynamic…
In magnetic fields applied within the angular range of the surface superconductivity state a magnetically anisotropic layered medium is created in structurally isotropic, sufficiently thick niobium films. Surface (Kulik) vortices residing…
High resolution direct numerical simulations of rotating and flapping bumblebee wings are presented and their aerodynamics is studied focusing on the role of leading edge vortices and the associated helicity production. We first study the…
The resonant energy transfer mechanism, responsible for the presence of fractal patterns in the velocity diagrams of kink-antikink scattering, is analyzed for a family of two-component scalar field theory models, in which the kink solutions…
Compared to electronic phase transitions, structural phase transitions of crystals are challenging to control due to the energy cost of breaking dense solid bonds. Recently, however, electric field switching of stacking configuration…
Super-large-scale particle image velocimetry and flow visualization with natural snowfall is used to collect and analyze multiple datasets in the near wake of a 2.5 MW wind turbine. Each dataset captures the full vertical span of the wake…
The separated flow over a wall-mounted bump geometry under harmonic oscillations of the inflow stream is investigated by direct numerical simulations. The bump geometry gives rise to streamwise pressure gradients similar to those…
We study the dynamics of vortices in strongly disordered $d=2$ Josephson junction arrays and superconducting films driven by a current. We find a dynamic phase transition in vortex flow at a current $I_p>I_c$. Below $I_p$ there is plastic…
We consider induced topological transitions in a wire made from cylindrical superconducting film. During a transition, a pulse of electric current causes transport of a virtual vortex-antivortex pair around the cylinder. We consider both…
We study phase transition from the Mott insulator to superfluid in a periodic optical lattice. Kibble-Zurek mechanism predicts buildup of winding number through random walk of BEC phases, with the step size scaling as a the third root of…
We study kinetic models for traffic flow characterized by the property of producing backward propagating waves. These waves may be identified with the phenomenon of stop-and-go waves typically observed on highways. In particular, a refined…
Electrokinetic flow can be generated as a highly coupled phenomenon among velocity field, electric conductivity field and electric field. It can exhibit different responses to AC electric fields in different frequency regimes, according to…
We employ detailed numerical simulations to probe the mechanism of flow reversals in two-dimensional turbulent convection. We show that the reversals occur via vortex reconnection of two attracting corner rolls having same sign of…
We report real-space evidence for an in-plane vortex lattice (VL) transition in the multiband superconductor 2H-NbSe2, observed by laterally imaging subsurface vortices with scanning tunneling spectroscopy. With magnetic field applied ||…
The dynamics of the electroweak phase transition in the early universe has profound implications for cosmology and particle physics. We systematically study the steady-state dynamics of bubble walls in scenarios where the transition is…
We present experiments on oscillating hydrofoils undergoing combined heaving and pitching motions, paying particular attention to connections between propulsive efficiency and coherent wake features extracted using modal analysis.…
The phase diagram of a vertex model introduced by P. Di Francesco (Nucl. Phys. B 525, 507 1998) representing the configurations of a square lattice which can fold with different bending energies along the main axes and the diagonals has…
The present thesis deals with the non-modal linear analysis of 3D perturbations in wall flows. In the first part,a solution to the Orr-Sommerfeld and Squire IVP, in the form of orthogonal functions expansion, is researched. The Galerkin…
When a turbulent vortex impinges on a porous layer, it creates a complex multiscale interaction: the wake structures that form in the free fluid engage with the intricate geometry of the pores, and this interplay governs both the turbulent…
A photonic Floquet topological insulator has previously been experimentally realized in an array of evanescently-coupled helical waveguides. In the topological regime probed by that experiment, the chirality of the single topological edge…