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Enabled by national commercialization of massive shale resources, Gas Turbines continue to be the backbone of power generation in the US. With the ever-increasing demand on efficiency, GT combustion sections have evolved to include shorter combustion lengths and multiple axial staging of the fuel, while at the same time operating at ever increasing temperatures. This paper presents the results of very detailed Large Eddy Simulations of one (or two) combustor can(s) for a 7HA GE Gas Turbine Engine over a range of operating parameters. The model of the simulated combustor can(s) includes (include) all the details of the combustor from compressor diffuser to the end of the stationary part of the first stage of the turbine. It includes the geometries of multiple pre-mixers within the combustion can(s) and the complete design features for axial fuel staging. All simulations in this work are performed using the CharLES flow solver developed by Cascade Technologies. CharLES is a suite of massively parallel CFD tools designed specifically for multiphysics LES in high-fidelity engineering applications. Thermo acoustic results from LES were validated first in the physical GE lab and then in full-engine testing. Both the trend as well as the predicted amplitudes for the excited axial dominant combustion mode matched the data produced in the lab and in the engine. The simulations also revealed insight into the ingestion of hot gases by different hardware pieces that may occur when machine operates under medium to high combustion dynamics amplitudes. This insight then informed the subsequent design changes which were made to the existing hardware to mitigate the problems encountered.

In this study, large eddy simulations (LES) of supersonic combustion using a compressible flamelet/progress variable (CFPV) approach are performed for the HIFiRE scramjet at Mach 8 flight conditions. The LES results show good agreement with the ground test experimental measurements. The combustion model is based on an efficient flamelet approach, where compressibility corrections are devised based on assumed functional forms of important thermo-chemical quantities. Specifically, the source term of the progress variable is rescaled with the local density and temperature in the LES, leading to improved predictions relative to existing flamelet models. A modified equilibrium wall-model, capable of predicting the viscous heating, is used in the viscous near-wall region. Temperature near the wall increases significantly due to viscous heating, enhancing the reaction rate and heat-release. This is shown to be a crucial step for accurately predicting the pressure rise in the combustor.

In this work, a rich-dome aviation combustor operating over a range of high-power conditions is investigated using multiple Large Eddy Simulations (LES). The LES flow solutions are obtained with CharLES, a massively-parallel framework for compressible, reacting flows in complex geometries. The CharLES solver constructs a body-conforming mesh from the 3D Voronoi diagram of a set of regularly distributed seed points within the computational domain. The computational domain spans from the compressor exit plane to the combustor exit plane and includes the passages around the combustor liners. A baseline solution is first obtained at nominal conditions using a reference grid and validated using non-dimensional exit profile. Non-intrusive Uncertainty Quantification (UQ) is then employed to characterize the uncertainties on a few key combustor metrics. It is found that the overall variability at the exit plane is actually larger than the input uncertainty. This highlights the non-linear coupling between the flow and the reacting processes inside the combustor. Areas of high temperature variability are highlighted, especially downstream of the dilution holes. Finally, it is found that uncertainty in fuel flowrate has a greater impact on outlet quantities whereas uncertainty in air inlet temperature has a greater impact on liner quantities.

Sphere close packed (SCP) lattice arrangements of points are well-suited for formulating symmetric quadrature rules on simplexes, as they are symmetric under affine transformations of the simplex unto itself in 2D and 3D. As a result, SCP lattice arrangements have been utilized to formulate symmetric quadrature rules with N"p=1, 4, 10, 20, 35, and 56 points on the 3-simplex (Shunn and Ham, 2012). In what follows, the work on the 3-simplex is extended, and SCP lattices are employed to identify symmetric quadrature rules with N"p=1, 3, 6, 10, 15, 21, 28, 36, 45, 55, and 66 points on the 2-simplex and N"p=84 points on the 3-simplex. These rules are found to be capable of exactly integrating polynomials of up to degree 17 in 2D and up to degree 9 in 3D.

We present highly resolved large eddy simulation (LES) of a realistic effusion cooling geometry. The test case features mixing between a high-density working fluid (CO2) and a low-density crossflow (air) to mimic the density stratification in typical gas turbine cooling flows. The coolant CO2 is fed from a plenum into the air channel through a series of 52 inclined orifices in a staggered arrangement. Highly detailed LES computations presented in this study resolved entire 52 cooling holes to accurately capture realistic jet-to-jet interactions which are critical in cooling film formation. Two different blowing ratios (M) are analyzed, comparing predictions obtained from wall-modeled and wall-resolved grids. M is defined as the density times the velocity of the coolant divided by that of the air channel. These values are chosen so that the coolant jets are attached to the wall (M=0.457) in one case, and detached (M=1.22) in the other. Results show that for the two blowing ratios analyzed, the wall-resolved adiabatic effectiveness based on CO2 concentration compares favorably with that obtained from pressure sensitive paint (PSP) measurements. The mixing and turbulence characteristics upstream and downstream of the jets are characterized using the probability density function of CO2 concentration and its impact on cooling effectiveness. It is found that the lower blowing ratio case provides more initial cooling than the higher blowing ratio case because the cooling jets attach to the surface and induce interactions among adjacent columns of jet streams. This provides more uniform film coverage and therefore higher initial cooling effectiveness. In the higher blowing ratio case, however, this interaction is significantly delayed due to lift-off of the coolant jets. PDF analysis shows interactions between adjacent cooling stream columns near the wall do not occur until the last jets. Although both the wall-resolved (WR) and wall-modeled (WM) cases show consistent trends with the PSP measurement, the wall-resolved cases show better quantitative agreement overall.

The primary feedstock for synthetic fuel production is syngas, a mixture of carbon monoxide and hydrogen. Current hydrogen production technologies rely upon fossil fuels and produce significant quantities of greenhouse gases as a byproduct. This is not a sustainable means of satisfying future hydrogen demands, given the current projections for conventional world oil production and future targets for carbon emissions. For the past six years, the Idaho National Laboratory has been investigating the use of high-temperature steam electrolysis (HTSE) to produce the hydrogen feedstock required for synthetic fuel production. High-temperature electrolysis water-splitting technology, combined with non-carbon-emitting energy sources, can provide a sustainable, environmentally-friendly means of large-scale hydrogen production. Additionally, laboratory facilities are being developed at the INL for testing hybrid energy systems composed of several tightly-coupled chemical processes (HYTEST program). The first such test involved the coupling of HTSE, CO2 separation membrane, reverse shift reaction, and methanation reaction to demonstrate synthetic natural gas production from a feedstock of water and either CO or a simulated flue gas containing CO2. This paper will introduce the initial HTSE and HYTEST testing facilities, overall coupling of the technologies, testing results, and future plans.

Situational awareness in the operations and supervision of a industrial system means that decision making entity, whether machine or human, have the important data presented in a timely manner. An optimal presentation of information such that the operator has the best opportunity accurately interpret and react to anomalies due to system degradation, failures or adversaries. Anticipated problems are a matter for system design; however, the paper will focus on concepts for situational awareness enhancement for a human operator when the unanticipated or unaddressed event types occur. Methodology for human machine interface development and refinement strategy is described for a synthetic fuels plant model. A novel concept for adaptively highlighting the most interesting information in the system and a plan for testing the methodology is described.

The purpose of this document is to report the first year accomplishments of two coordinated Laboratory Directed Research and Development (LDRD) projects that utilize a hybrid energy testing laboratory that couples various reactors to investigate system reactance behavior. This work is the first phase of a series of hybrid energy research and testing stations - referred to hereafter as HYTEST facilities – that are planned for construction and operation at the Idaho National Laboratory (INL). A HYTEST Phase I facility was set up and commissioned in Bay 9 of the Bonneville County Technology Center (BCTC). The purpose of this facility is to utilize the hydrogen and oxygen that is produced by the High Temperature Steam Electrolysis test reactors operating in Bay 9 to support the investigation of kinetic phenomena and transient response of integrated reactor components. This facility provides a convenient scale for conducting scoping tests of new reaction concepts, materials performance, new instruments, and real-time data collection and manipulation for advance process controls. An enclosed reactor module was assembled and connected to a new ventilation system equipped with a variable-speed exhaust blower to mitigate hazardous gas exposures, as well as contract with hot surfaces. The module was equipped withmore » a hydrogen gas pump and receiver tank to supply high quality hydrogen to chemical reactors located in the hood.« less