Intake Ground Vortex Prediction Methods

Optical vortex coronagraphs on ground-based telescopes

The optical vortex coronagraph is potentially a remarkably effective device, at least for an ideal unobstructed telescope. Most groundbased telescopes however suffer from central obscuration and also have to operate through the aberrations of the turbulent atmosphere. This note analyzes the performance of the optical vortex in these circumstances and compares to some other designs, showing that...

Vortex Method Simulation of Ground Vehicle Aerodynamics

Recent results are presented from the application of a grid-free vortex method to the prediction of turbulent aerodynamic flows produced by road vehicles. The approach has the character of a large eddy simulation and incorporates a fast technique for evaluating the mutual interactions of several million vortex elements needed in describing the dynamically significant structure of the turbulent ...

Fast Vortex Methods

We present three fast adaptive vortex methods for the 2D Eu-ler equations. All obtain long-time accuracy at almost optimal cost by using four tools: adaptive quadrature, free-Lagrangian formulation, the fast multipole method and a nonstandard error analysis. Our error analysis halves the diierentiability required of the ow, suggests an eecient new balance of smoothing parameters , and combines ...

Quadratic Convergence of Vortex Methods

We prove quadratic convergence for two-dimensional vortex methods with positive cutoffs. The result is established for flows with initial vorticity three times continuously differentiable and compact support. The proof is based on a refined version of a convergence result. Introduction. The purpose of this paper is to prove that vortex methods with positive cutoffs can converge quadratically if...

Fast Adaptive 2D Vortex Methods