Aspects of three-dimensional parabolic equation computations

Three Dimensional Transonic Flow Computations Over a Projectile and at the Base Region

Three Dimensional Imaging for Magnetohydrodynamic Computations

Data produced by three dimensional MHD calculations are often difficult to visualize. Here we present a technique to view field lines of vector fields and one to display multiple isosurfaces of scalar fields. These methods do not rely on expensive commercial software and are general enough to be applied to other research sectors where visualization of 3D fields is important. Printed copies of t...

A Three-Dimensional Parabolic Equation Applied to VHF/UHF Propagation over Irregular Terrain

The two-dimensional (2-D) parabolic equation (PE) is widely used for making radiowave propagation predictions in the troposphere. The effects of transverse terrain gradients, propagation around the sides of obstacles, and scattering from large obstacles to the side of the great circle path are not modeled, leading to prediction errors in many situations. In this paper, these errors are addresse...

Three-dimensional Sound Propagation Models Using the Parabolic-equation Approximation and the Split-step Fourier Method

The split-step Fourier method is used in three-dimensional parabolic-equation (PE) models to compute underwater sound propagation in one direction (i.e. forward). The method is implemented in both Cartesian (x, y, z) and cylindrical (r, θ, z) coordinate systems, with forward defined as along x and radial coordinate r, respectively. The Cartesian model has uniform resolution throughout the domai...

A three-dimensional, two-way, parabolic equation model for acoustic backscattering in a cylindrical coordinate system

A new PE model for solving three-dimensional, forward and backward sound propagation in a cylindrical coordinate system is presented. The model marches a wave field in the radial direction including the azimuthal diffraction effects, and solves for a backscattered field based on a three-dimensional, single scattering approach. A periodic sidewall boundary condition is applied for computations i...