Efficient non-uniform orthogonal mesh generation algorithm for cylindrical FDTD applications
The paper presents an efficient non-uniform, orthogonal mesh generation algorithm for the analysis and design of cylindrical microwave devices and integrated circuits using the cylindrical finite-difference time-domain (CFDTD) methods. By using this algorithm, we can easily generate a suitable CFDTD grid which is fitting for the developed CFDTD Maxwell's solver.
AutoMesh: an automatically adjustable, nonuniform, orthogonal FDTD mesh generator
In this article, we introduce a three-dimensional, automatically adjustable, non-uniform orthogonal-mesh generator, AutoMesh, developed using a Windows application-development package, Microsoft Visual Basic. The developed mesh-generating package can efficiently produce geometrical and material data files for a complex electromagnetic configuration that serve as inputs to a generalized non-uniform finite-difference time-domain (FDTD) Maxwell's equations solver. In addition, the fruitful graphical functions of the package insure not only the accuracy of the generated data files, but also the ease of mesh generation for complex objects. Herein, we first present the algorithm of mesh generation, and then illustrate graphical features of the package.
HYPERGOLIC REACTION MECHANISMS OF CATALYTICALLY PROMOTED FUELS WITH ROCKET GRADE HYDROGEN PEROXIDE
Abstract The coupling of the physical and chemical processes controlling the ignition delays (τ ign ) of hypergolic propellants complicates the direct analysis of the transient ignition processes. The transport properties of both the propellants and the ambient gas, and the heat of vaporization and reaction affect τ ign and must be considered experimentally. Furthermore, since hypergolic ignition occurs, by definition, on contact, the mechanics of initial contact and subsequent mixing can affect τ ign and must also be considered. Experimental results from a study of the hypergolic ignition of a catalytically promoted fuel with rocket grade hydrogen peroxide (RGHP) are presented. Statistical analysis of the experimental data was conducted to evaluate the relative effects of RGHP concentration, initial ambient pressure, and the ambient gas on τ ign . At RGHP concentrations of less than 92% in water, stable ignition was difficult to achieve. At sufficiently high Lewis number, an oscillatory ignition process is observed. A phenomenological model comprising mixing, RGHP decomposition, fuel heating and vaporization, and auto-ignition is presented and compared to the experimental results.