Laboratory experiments were used to explore the influence of spatial focusing and diffraction on the evolution of unsteady, three-dimensional, deep-water wave-packets with a constant-steepness spectrum. The wave-packets were generated by thirteen independently programmed paddles and evolved to breaking near the midpoint of a 4m x 11 m test section. Detailed measurements of surface displacements...

The Baer and Rinzel model of dendritic spines uniformly distributed along a dendritic cable is shown to admit a variety of regular traveling wave solutions including solitary pulses, multiple pulses and periodic waves. We investigate numerically the speed of these waves and their propagation failure as functions of the system parameters by numerical continuation. Multiple pulse waves are shown ...

We consider a dynamo wave in the solar convective shell for the kinematic αω-dynamo model. The spectrum and eigenfunctions of the corresponding equations are derived analytically with the aid of the WKB method. Our main aim here is to investigate the dynamo wave behavior in the vicinity of the solar poles. Explicit expressions for the incident and reflected waves are obtained. The reflected wav...

In isotropic bistable media, a vortex pair typically evolves into rotating spiral waves. In an anisotropic system, instead of spiral waves, the vortices can form wave fragments that propagate with a constant speed in a given direction determined by the system's anisotropy. The fragments may propagate invariably, shrink, or expand. We develop a kinematic approach for the study of vortex-pair dyn...

NASA/TM—2013-217850 1 ∆t∗ nondimensional time step, ∆t/(L/V0) kinetic energy dissipation rate 1 kinetic energy dissipation rate computed from deviatoric strain rate 3 kinetic energy dissipation rate computed from pressure dilatation κ angular wave number μ kinematic viscosity ν spectroscopic wave number ωi vorticity vector Ω volume ρ density σ filter damping coefficient τij stress tensor ζ enst...

The Radcliffe Wave (RW) is a recently discovered sinusoidal vertical feature of dense gas in the proximity Sun. In disk plane, it aligned with Local Arm. However, origin its undulation still unknown. This study constrains kinematics RW, using young stars and open clusters as tracers, explores possibility this oscillation being part more extended mode. We median velocity trends along RW extend f...