Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase II | Award Amount: 500.00K | Year: 2010
Investigations into JP-10 combustion chemistry thus far can be characterized as preliminary. The detailed chemical kinetic mechanisms that have been published are limited in their ability to reproduce experimental data. The combustion chemistry of JP-10 is highly complex, involving hundreds if not thousands of species and thousands of chemical reactions. A detailed kinetic model capable of predicting ignition delay, heat release, and species concentrations is an important step toward understanding more complex, multidimensional phenomena such as flame-holding and extinction behavior in ramjet and scramjet applications. The proposed Phase II project will complete the development of a pressure dependent, detailed chemical kinetic mechanism for combustion and pyrolysis of JP-10 started in the Phase I project. The comprehensive mechanism will be validated against literature data and new data generated in Phase II. The mechanism will be in Chemkin format and will include thermodynamic and transport properties for all species. The mechanism will be derived from fundamental thermochemical principles using high-level quantum chemistry calculations, without extensive tuning to match data. Adjustments to rate parameters will be limited to the uncertainties of the methods used to obtain them. Transport properties of individual species will be developed from quantum chemistry and group additivity calculations.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 100.00K | Year: 2010
The proposed project will leverage REI’s experience creating and applying reduced chemical kinetic mechanisms for JP-8 with source-term speed-up techniques such as in-situ adaptive tabulation (ISAT) and artificial neural networks (ANN) to develop techniques for speeding evaluation of JP-8 kinetics in gas turbine combustor simulations. During Phase I, pre-trained ANN models using reduced chemical kinetic mechanisms will be combined with an existing ISAT code. The ANN models will be trained using a Linear Eddy Model (LEM) code to generate a range of thermochemical states similar to those found in combustion simulations. The combined ANN-ISAT model will be benchmarked against direct integration, again using an LEM code and a Partially-Stirred Reactor (PaSR) code. Efforts will initially focus on simple fuels such as hydrogen and methane, then advance to JP-8 reduced mechanisms created from previous R&D projects. Phase I work will also investigate the benefits of combining multiple reduced mechanisms into a single source term subroutine with the sub-mechanisms carefully selected for high accuracy and low stiffness over a specified range of conditions. Phase II work will focus on implementation/demonstration of the Phase I techniques into the FLUENT CFD code to simulate gas turbine combustors. BENEFIT: Requirements for high performance gas turbine engines have continued to push the state-of-the-art in combustion technology. CFD tools have the potential for assessing performance, stability, and durability in gas turbine engine combustors because simulations can model conditions that can’t be easily duplicated experimentally and can provide information on quantities that are difficult to measure. CFD simulations can thus reduce the length and cost of the design cycle and test innovative concepts quickly and inexpensively compared to building and testing prototypes. However, useful CFD simulations of gas turbine combustors and augmentors require accurate and efficient models of hydrocarbon chemistry and turbulence interaction of the reacting flows. This project will provide the DoD and contractor personnel with a robust, accurate, validated, computationally efficient modeling capability for JP-8 that can be integrated into chemical kinetic solvers and CFD packages used for gas turbine combustor modeling. The models will be based on the best available reaction kinetics descriptions. The combustion modeling capability provided by this project will allow engineers and scientists to more accurately assess gas turbine engine designs and provide better guidance for ground and flight tests. While this software will focus initially on Air Force gas turbine applications, other areas will benefit from the technology as well. These include: (1) Support of U.S. government gas turbine development programs such as VAATE (Versatile, Affordable, Advanced Turbine Engine) and military programs that support VAATE, such as ADVENT (Adaptive Versatile Engine Technology); (2) Support of commercial companies that work in gas turbine engine production and R&D such as General Electric, Honeywell, Rolls-Royce North America, UTRC / Pratt & Whitney, Williams International and Teledyne Continental Motors and to companies that provide computational tools to these companies, such as ANSYS/Fluent, CD-ADAPCO, Metacomp Technologies, CFD Research Corporation and Reaction Design; (3) Use of numerical and chemistry modeling techniques in other software applications. Accurate, verified models of combustion chemistry that can be efficiently run in CFD simulations are in critical demand in all areas of reacting flow simulation including simulations of gas turbine and internal combustion engines, mineral and chemical processing furnaces, as well as in the areas of energy production, incineration, rocket/SCRAMJET propulsion, and fire and explosion research. REI provides CFD consulting services in many of these areas and expects that the type of models developed here would find application in a wide variety of industries outside the target application of gas turbine combustion.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 149.93K | Year: 2015
Problem Statement: The evolution of hydraulic fracturing has enabled development of unconventional natural gas resources that previously would not have been economical. The volume of water required for these operations is a major concern. Industry is actively seeking methods to reduce water usage and increase the amount of gas recovered per unit of water used to stimulate the formation. There is substantial evidence that the rate and method of flowback of the fracturing fluid has a significant impact on the amount of water recovered and well productivity. Proposed Solution: REI proposes to develop a multiphase Computational Fluid Dynamics (CFD) model and an accompanying reduced order model (ROM) tool to predict flowback of the fracturing fluid from a well over time. The ROM tool will use a database of CFD solutions to provide quick estimates of the flowback rate and the potential impact on future gas production. The ROM will be designed to allow field operators and fracturing service companies to optimize the amount of water injected during stimulation, recover more of the injected water and increase the expected ultimate recovery of the natural gas in the formation. Phase I Work Plan REI will develop a Computational Fluid Dynamics (CFD) model of the Flowback process using the ANSYS/Fluent commercial CFD code. A database of CFD model solutions for flowback will be generated. A reduced order model (ROM) tool will be created using the database of CFD solutions. The CFD solutions and ROM tool will be benchmarked against field data. Commercial Applications and Other Benefits: The completed ROM tool will allow field operators and fracturing service companies to (a) optimize the flowback rate and recovery of the fracturing fluid (primarily water) before stimulating a well and (b) history match real flowback data with the model to better understand the geometry properties of the produced fractures. This will result in less water usage per fracturing job, higher recovery rates of water from the well, higher initial production rates and higher ultimate recovery of the resource. This will allow the United States to continue to lead in natural gas production while lowering the amount of water used. Key Words: hydraulic fracturing, flowback, well cleanup, unconventional Summary for Members of Congress This project will develop a computational tool designed to allow engineers to optimize the injection and recovery of water used in hydraulic fracturing operations. The proposed technology will improve the efficiency of natural gas production from unconventional resources and reduce the amount of water used.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 749.98K | Year: 2013
With the current state of world events, the threat of buried explosives used against military vehicles is more pronounced than ever before. The introduction of the MRAP and MTVR vehicles have helped mitigate this threat to a degree, but military personnel continue to suffer from both death and serious bodily injury as a result of IED/mine explosions. To address this need, improved comprehensive simulation capabilities are needed to help design improved safety components for vehicle occupants. The proposed effort, which builds on previous work performed under US Army funding, will develop next-generation simulation capabilities to better predict the effects of buried explosives on ground vehicles and occupants. Blast and soil modeling will be performed using advanced simulation tools developed as part of the DoE ASCI program at the University of Utah and the vehicles will be modeled with the LS-DYNA FE code. Occupant modeling will be performed using LS-DYNA. The final product of the Phase II will be a micro-coupled MPMICE-LS-DYNA model, which leverages the best capabilities of each simulation tool. Comparisons will be made between simulations of the MTVR exposed to a buried threat and live-fire test data for the same configuration.
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase II | Award Amount: 750.00K | Year: 2011
The objective of the proposed Phase II STTR effort is to develop a validated computational tool to predict the afterburning of non-ideal munitions containing metal and hydrocarbon fuels. The activities outlined devise a well-coordinated collaboration among researchers from Reaction Engineering International (REI) and the State University of New York at Buffalo (UB). The activities proposed will build on the previous collaboration between REI and UB in modeling and simulation of advanced computational frameworks for abnormal thermal and mechanical environments. The modeling strategy proposed includes several unique features that are important for understanding and predicting the ignition of compressible multiphase flows. These effects include both heterogeneous and homogeneous particle reactions, particle compressibility, and a turbulence modeling approach that naturally includes effects of group combustion. The modeling will be housed into a new 3D supervisory simulation framework pioneered by REI for examining blast environments that includes support for complex geometries and a variety of explosives. It is anticipated that the final tool will be commercialized for both military and non-military customers to either design or better understand the blast loads from non-ideal explosives.