this paper presents numerical calculations for podded propulsion system using vortex theory and potential panel method. the method discretizes the surface boundary of the body (propeller +pod+strut) and obtained the vortex and propeller surface and potential on strut and pod. a model propeller and strut are considered for these calculations and the results of pressure distribution, flow field a...

We study the interplay between Dirac eigenmodes and center vortices in SU(2) lattice gauge theory. In particular we focus on vortex-removed configurations and compare them to an ensemble of configurations with random changes of the link variables. We show that removing the vortices destroys all zero modes and the near zero modes are no longer coupled to topological structures. The Dirac spectru...

Parallel discrete vortex methods are ideally suited for studying the behaviour of bluff body wakes due to their ability to capture the motion of vortex structures and lack of downstream grid boundaries. However, the availability of suitable parallel computers to run long simulations is always an issue. The convergence of the high-end workstation and commodity PC markets means that it is now pos...

We numerically study the topology of optical vortex lines (nodal lines) in volumes of optical speckle, modeled as superpositions of random plane waves. It is known that the vortex lines may be infinitely long, or form closed loops. Loops are occasionally threaded by infinite lines, or linked with other loops. We find the probability of a loop not being threaded decays exponentially with the len...

We study the formation of vortices in a U(1) gauge theory following a firstorder transition proceeding by bubble nucleation, in particular the effect of a low velocity of expansion of the bubble walls. To do this, we use a twodimensional model in which bubbles are nucleated at random points in a plane and at random times and then expand at some velocity vb < c. Within each bubble, the phase ang...

Tangles of string typically become knotted, from macroscopic twine down to long-chain macromolecules such as DNA. Here, we demonstrate that knotting also occurs in quantum wavefunctions, where the tangled filaments are vortices (nodal lines/phase singularities). The probability that a vortex loop is knotted is found to increase with its length, and a wide gamut of knots from standard tabulation...

Vortex is a new family of one-way hash functions which has been submitted to the NIST SHA-3 competition. Its design is based on using the Rijndael block cipher round as a building block, and using a multiplication-based merging function to support fast mixing in a small number of steps. Vortex is designed to be a fast hash function, when running on a processor that has AES acceleration and has ...

We study the melting transition of the low-temperature vortex solid in strongly anisotropic layered superconductors with a concentration of random columnar pinning centers small enough so that the areal density of the pins is much less than that of the vortex lines. Both the external magnetic field and the columnar pins are assumed to be oriented perpendicular to the layers. Our method, involvi...

The topological charge is constructed for SU(3) center vortex world-surfaces composed of elementary squares on a hypercubic lattice. In distinction to the SU(2) case investigated previously, it is necessary to devise a proper treatment of the color structure at vortex branchings, which arise in the SU(3) case, but not for SU(2). The construction is used to evaluate the topological susceptibilit...

We present results from extensive simulations of driven vortex lattices interacting with periodic arrays of pinning sites. Changing an applied driving force produces a rich variety of novel dynamical plastic flow phases which are very distinct from those observed in systems with random pinning arrays. Signatures of the transition between these different dynamical phases include sudden jumps in ...