The dynamics of vortex flow is studied theoretically and numerically. Starting from a local analysis, where the perturbation in the vortex flow is Fourier decomposed in both radial and azimuthal directions, a modified Chebyshev polynomial method is used to discretize the linearized governing operator. The spectrum of the operator is divided into three groups: discrete spectrum, free-stream spec...

Pelagic copepods jump to relocate, to attack prey and to escape predators. However, there is a price to be paid for these jumps in terms of their energy costs and the hydrodynamic signals they generate to rheotactic predators. Using observed kinematics of various types of jumps, we computed the imposed flow fields and associated energetics of jumps by means of computational fluid dynamics simul...

Presented are quantum simulation results using a measurement-based quantum lattice gas algorithm for Navier-Stokes fluid dynamics in 2+1 dimensions. Numerical prediction of the kinematic viscosity was measured by the decay rate of an initial sinusoidal flow profile. Due to local quantum entanglement in the quantum lattice gas, the minimum kinematic viscosity in the measurement-based quantum lat...

A theoretical investigation into the vortex-speed selection within the rotating-disk boundary layer is conducted. Two methods are used which are different to previous investigations in the literature and enable analysis of a particular vortex speed with respect to the rotating surface. Using these methods (together with arguments based on critical Reynolds numbers, unstable parameter ranges and...

A flow state consisting of two oppositely traveling waves (TWs) with oscillating amplitudes has been found in the counter-rotating Taylor-Couette system by full numerical simulations. This structure bifurcates out of axially standing waves that are nonlinear superpositions of left- and right-handed spiral vortex waves with equal time-independent amplitudes. Beyond a critical driving, the two sp...

The problem of controlling the position of a pair of point vortices using a strain field or a field of a single souce/sink is considered. The problem dimension is reduced by averaging over the fast rotation of vortices around the center of vorticity. Control is assumed to be function of rotation phase only. For the case of the strain field actuation, optimal control problem is posed in three di...

To date, several investigations have considered the prospect of enhanced dissipation of a vortex pair due to elliptic (short wave) instabilities. Recent studies indicate that these modes have the potential to significantly reduce the time taken to dissipate vortex pairs. This has generated interest in the aviation industry, where aircraft trailing wakes pose a significant hazard for nearby airc...

The steady motion of a symmetric, finite core size, counterrotating vortex pair is characterized by circulation r, a velocity V, and a spacing 2xooo In the classical limit of a point vortex, the normalized velocity, vx~/r, is 1/(41T). The effect of finite core size is to reduce the normalized velocity below the value for a point vortex. The flow is governed by a single geometrical parameter R/x...