In this paper we study the behavior of a premixed turbulent methane flame in three dimensions using numerical simulation. The simulations are performed using an adaptive time-dependent low Mach number combustion algorithm based on a second-order projection formulation that conserves both species mass and total enthalpy. The species and enthalpy equations are treated using an operator-split approach that incorporates stiff integration techniques for modeling detailed chemical kinetics. The methodology also incorporates a mixture model for differential diffusion. For the simulations presented here, methane chemistry and transport are modeled using the DRM-19 (19-species, 84-reaction) mechanism derived from the GRIMech-1.2 mechanism along with its associated thermodynamics and transport databases. We consider a lean flame with equivalence ratio 0.8 for two different levels of turbulent intensity. For each case we examine the basic structure of the flame including turbulent flame speed and flame surface area. The results indicate that flame wrinkling is the dominant factor leading to the increased turbulent flame speed. Joint probability distributions are computed to establish a correlation between heat release and curvature. We also investigate the effect of turbulent flame interaction on the flame chemistry. We identify specific flame intermediates that are sensitive to turbulence and explore various correlations …

Recent progress in simulation methodologies and new, high-performance parallel architectures have made it is possible to perform detailed simulations of multidimensional combustion phenomena using comprehensive kinetics mechanisms. However, as simulation complexity increases, it becomes increasingly difficult to extract detailed quantitative information about the flame from the numerical solution, particularly regarding the details of chemical processes. In this paper we present a new diagnostic tool for analysis of numerical simulations of combustion phenomena. Our approach is based on recasting an Eulerian flow solution in a Lagrangian frame. Unlike a conventional Lagrangian viewpoint in which we follow the evolution of a volume of the fluid, we instead follow specific chemical elements, e.g., carbon, nitrogen, etc., as they move through the system. From this perspective an ''atom'' is part of some molecule that is transported through the domain by advection and diffusion. Reactions ca use the atom to shift from one species to another with the subsequent transport given by the movement of the new species. We represent these processes using a stochastic particle formulation that treats advection deterministically and models diffusion as a suitable random-walk process. Within this probabilistic framework, reactions can be viewed as a Markov process transforming molecule to molecule …

In this paper we study the formation of NO in laminar, nitrogen diluted methane diffusion flames that are seeded with ammonia in the fuel stream. We have performed numerical simulations with detailed chemistry as well as laser-induced fluorescence imaging measurements for a range of ammonia injection rates. For comparison with the experimental data, synthetic LIF images are calculated based on the numerical data accounting for temperature and fluorescence quenching effects. We demonstrate good agreement between measurements and computations. The LIF corrections inferred from the simulation are then used to calculate absolute NO mole fractions from the measured signal.The NO formation in both doped and undoped flames occurs in the flame sheet. In the undoped flame, four different mechanisms including thermal and prompt NO appear to contribute to NO formation. As the NH3 seeding level increases, fuel-NO becomes the dominant mechanism and N2 shifts from being a net reactant to being a net product. Nitric oxide in the undoped flame as well as in the core region of the doped flames are underpredicted by the model; we attribute this mainly to inaccuracies in the NO recycling chemistry on the fuel-rich side of the flame sheet.

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Refractive index changes have been induced inside bulk fused silica by using femtosecond (fs) laser pulses tightly focused inside the material. Waveguides have been fabricated inside the glass by scanning the glass with respect to the focal point of the laser beam. The refractive index change is estimated to be {approx} 10{sup -4}. Other more complex three-dimensional structures have also been fabricated (curved waveguides, splitters, and interferometers). We also report on fluorescence spectroscopy of the fs-modified fused silica using a confocal microscopy setup. Using a 488 nm excitation source, a fluorescence at 630 nm is observed from the modified glass, which is attributed to the presence of non-bridging oxygen hole center (NBOHC) defects created by the fs pulses. The fluorescence decays with prolonged exposure to the 488 nm light, indicating that the defects are being photobleached by the excitation light.

A method was developed to enhance geothermal steam production from two-phase wells at THE Geysers Geothermal Field. The beneficial result was increased geothermal production that was easily and economically delivered to the power plant.

Two BWR fuels [64 and 71 (MWd)/kgU], one of which contained 2% Gd, and two PWR fuels [30 and 45 (MWd)/kgU], are tested by dripping groundwater on the fuels under oxidizing and hydrologically unsaturated conditions for times ranging from 2.4 to 8.2 yr at 90 C. The {sup 99}Tc, {sup 129}I, {sup 137}Cs, {sup 97}Mo, and {sup 90}Sr releases are presented to show the effects of long reaction times and of gadolinium on nuclide release. This investigation showed that the five nuclides at long reaction times have similar fractional release rates and that the presence of 2% Gd reduced the {sup 99}Tc cumulative release fraction by about an order of magnitude over that of a fuel with a similar burnup.

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Developed equipment consisted of a high magnetic field solenoid with supporting instrumentation for electron plasma confinement. The solenoid was designed and delivered in year 1. In year 2, it was mapped and the trap was created and commissioned. In parallel, an ongoing program of beam-plasma interaction studies was carried out with a lower field trap developed earlier. The trap was placed in the IUCF Coolor (an intermediate-energy electron-cooled storage ring) and the effects of the beam on the plasma were investigated, including energy and angular momentum transfer. Student projects carried out within the beam-plasma group also included development of a diagnostic with high spatial resolution, and preparation for extension of the beam-plasma interaction study to much lower beam energy. This became the principal group activity during the latter part of the project.

This project on heat transfer coefficients in metal permanent mold casting has been conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigation of squeeze casting at CMI-Tech Center (Now Hayes-Lemmerz Technical Center) and the experimental investigation of low pressure permanent mold casting at Amcast Automotive.

Second order optical nonlinearities were induced in commercial phosphate glasses (Schott, IOG-1) by the thermal poling technique. The induced {chi}{sup (2)} was measured via second harmonic generation using a fundamental beam from a 1064 nm mode-locked Nd:YAG laser. The nonlinear regions were characterized using the Maker-Fringe technique, in which the second harmonic signals were observed as a function of incident angle of the fundamental beam. The results show that the {chi}{sup (2)} profile has contributions from two distinct regions: a near-anodic surface region and a bulk. We have modeled the induced profile to fit our experimental results. The dependence of the induced nonlinearity on applied poling fields, temperatures and poling time is discussed.

The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture …

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Layering is the process whereby condensed deuterium tritium (DT) fusion fuel at 18-19 K is very uniformly distributed on the inside wall of an Inertial Fusion Energy (IFE) target. The quality and uniformity of the DT layer has a profound effect on the performance (gain) of the target. It would be a great advantage for indirect drive targets to carry out layering with the capsule already assembled in the hohlraum. One concept to accomplish this is to layer targets in controlled temperature, cryogenic tubes while they are being staged for feeding to the injection system. In this report we have demonstrated through extensive analysis that in-hohlraum layering is possible, but that variations in dimensions, alignments and material properties can easily cause the capsule temperature nonuniformity to exceed values needed to assure proper fuel layering. The concept shows sufficient promise to warrant continued investigation. Analysis alone cannot demonstrate the feasibility of in-hohlraum layering. One of the most basic and important experiments is the measurement of the properties of hohlraum materials. Such measurements must be performed with sufficient accuracy to demonstrate predictability and repeatability to the level of precision needed to maintain thermal control. Continued close interaction between target designers and target …