This paper presents a novel non-rigid registration method. The main contribution of the method is the modeling of the vorticity (respectively divergence) of the deformation field using vortex (respectively sink and source) particles. Two parameters are associated with a particle: the vorticity (or divergence) strength and the influence domain. This leads to a very compact representation of vort...

[1] We present an experimental and numerical study of a rotating fluid with a zonal flow produced from small-scale eddies, a common feature of many planetary systems. The apparatus consists of a water-filled annular tank with a sloped bottom. Flow is forced mechanically at small, nonaxisymmetric scales. Potential vorticity is materially conserved and well-mixed. This implies the existence of no...

We suggest an algorithm for the calculation of large-amplitude traveling water waves in irrotational flows and in flows with constant and nonconstant vorticity, respectively. The algorithm is based on a quite general partial differential equation constrained optimization formulation, maximizing the wave amplitude subject to the PDE constraint that the Euler equations hold. Numerical examples il...

The effect of yaw angle on wake characteristics behind a yawed square cylinder was examined at a Reynolds number (Re) of 3600. Velocity and vorticity fluctuations were measured using a one-dimensional hot-wire vorticity probe. It is found that the large-scale structures contribute the most to the streamwise and transverse velocity variances, as well as Reynolds shear stress, despite the reducti...

The transport of the potential vorticity gradient ∇q along surfaces of constant potential temperature θ is investigated for the stratified Euler, Navier–Stokes and hydrostatic primitive equations of the oceans and atmosphere, in terms of the divergence-less flux vector B = ∇Q(q)×∇θ , for any smooth function Q of the potential vorticity q. The flux vector B is shown to satisfy a transport equati...

 Abstract : The meshless local Petrov-Galerkin method with unity as the weighting function has been applied to the solution of the Navier-Stokes and energy equations. The Navier-Stokes equations in terms of the stream function and vorticity formulation together with the energy equation are solved for a driven cavity flow for moderate Reynolds numbers using different point distributions. The L2-...

We conduct long simulations with a Hamiltonian particle-mesh method for ideal fluid flow, to determine the statistical mean vorticity field. Lagrangian and Eulerian statistical models are proposed for the discrete dynamics, and these are compared against numerical experiments. The observed results are in excellent agreement with theoretical models, as well as the continuum statistical mechanica...

We derive boundary conditions for the vorticity equation with solid wall boundaries. The formulation uses a Dirichlet condition for the normal component of vorticity, and Neumann type conditions for the tangential components. In a Galerkin (integral) formulation the tangential condition is natural, i.e. it is enforced by a right-hand side functional and does not impose a boundary constraint on ...

We present a set of equations governing the motion of a body due to prescribed shape changes in an inviscid, planar fluid with nonzero vorticity. The derived equations, when neglecting vorticity, reduce to the model developed in [4] for swimming in potential flow, and are also consistent with the models developed in [2,5,15] for a rigid body interacting dynamically with point vortices. The effe...

Barotropic f -plane dipolar vortices were generated in a rotating fluid and a comparison was made with the so-called supersmooth f -plane solution which—in contrast to the classical Lamb–Chaplygin solution—is marked by an elliptical separatrix and a doubly continuously differentiable vorticity field. Dyevisualization and high-resolution particle-tracking techniques revealed that the observed di...