Traditionally, vector field visualization is concerned with 2D and 3D flows. Yet, many concepts can be extended to general dynamical systems, including the higher-dimensional problem of modeling the motion of finite-sized objects in fluids. In the steady case, the trajectories of these so-called inertial particles appear as tangent curves of a 4D or 6D vector field. These higher-dimensional flo...

Two approaches to defining almost-invariant surfaces for magnetic-fields with imperfect magnetic surfaces are compared. Both methods are based on treating magnetic field-line flow as a 1 :-dimensional Hamiltonian (or Lagrangian) dynamical system. In the quadratic-flux minimizing surface approach. the integral of the square of the action gradient over the toroidal and poloidal angles is minimize...

This numerical study examines the stirring properties of a 2D flow field with a specific focus on the alignment dynamics of tracer gradient vectors. In accordance with the study of Hua and Klein [Physica D 113 (1998) 98], our approach involves the full second order Lagrangian dynamics and in particular the second order in time equation for the tracer gradient norm. If the physical space is part...

It is shown that the short wavelength ~k' 2 r i .1, k' is the characteristic wave vector, and r i is the ion Larmor radius! electromagnetic drift wave turbulence in typical conditions is unstable with respect to the excitation of large scale perturbations of the plasma flow and magnetic field. It is found that the generation of zonal flow is reduced ~compared to the long wavelength ion temperat...

PURPOSE Reliable outcome measures are needed to estimate changes in peripheral vision during future treatment clinical trials for retinal degeneration patients. The authors examined the short-term variability of Goldmann visual field (GVF) results converted to retinal areas in retinitis pigmentosa (RP) subjects. METHODS Two within-visit GVFs were obtained from one eye each of 37 RP subjects w...

In the process of conveying a medium, when inlet pressure is low, cavitation phenomenon easily occurs in pump, especially gas–liquid two-phase working condition. The occurrence has great impact on performance multiphase pump. this paper, SST (sheard stress transport) k-? turbulence model and ZGB (Zwart–Gerber–Belamri) were used to simulate helical axial flow pump (hereinafter referred as pump),...