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MPSalsa: A Finite Element Computer Program For Reacting Flow Problems Part 2  User's Guide
, 1996
"... Follows 1. This document can be downloaded from: http://www.cs.sandia.gov/CRF/mpsalsa.html 2. This work was partially funded by Department of Energy, Mathematical, Information, and Computational Sciences Division, and was carried out at Sandia National Laboratories, operated for the US Department ..."
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Cited by 20 (12 self)
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Follows 1. This document can be downloaded from: http://www.cs.sandia.gov/CRF/mpsalsa.html 2. This work was partially funded by Department of Energy, Mathematical, Information, and Computational Sciences Division, and was carried out at Sandia National Laboratories, operated for the US Department of Energy under contract no. DEACO494AL85000. 3. Parallel Computational Sciences Department (org. 9221). 4. Parallel Computing Sciences Department (org. 9226). 5. Chemical Processing Science Department (org. 1126). Acknowledgments We would like to thank Professor Michael Jensen for preparing a number of the fluid mechanics examples and for urging the development of the output routines, and Aaron Thomas for benchmarking an early version of the code. We would also like to thank Ed Boucheron for identifying many instances of undesirable functionality so that we could remove them from the code. Finally, we would like to thank Rod Schmidt for his careful reading of this document. Ab...
Ammonia conversion and NOx formation in laminar coflowing nonpremixed methaneair flames
 Combust. Flame
"... DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employ ..."
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DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, or
Integrated Multiscale Process Simulation
, 2002
"... We su"#LE) two approaches to integrated muegrated processsimusELL (IMPS),particu;qL# relevant to integrated circuE (IC) fabrication, in which models forequqV' (m) andfeatu` (lm) scales are solvedsimuEVLVqLE)Lq The first approachuro reguch grids, and is applied tolowpressu` chemical v ..."
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Cited by 3 (1 self)
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We su"#LE) two approaches to integrated muegrated processsimusELL (IMPS),particu;qL# relevant to integrated circuE (IC) fabrication, in which models forequqV' (m) andfeatu` (lm) scales are solvedsimuEVLVqLE)Lq The first approachuro reguch grids, and is applied tolowpressu` chemical vapor deposition (LPCVD) of silicon dioxide from tetraethoxysilane (T OS). The second approachupr uroachEq;`# meshes, and is applied to electrochemical deposition ( CD) of copper. The goal is to develop approaches to estimate "loading" in these processes; i.e., the e#ects of pattern density and topography on local deposition rates. This is accomplished by resolving pattern (mesoscopic, mm) scales, which are betweenequeenEq (0.11 m) andfeatu# scales 0:11 lm). In this work, wefocu on steadystatesimustat resus We close with a fewthouxx# on extending IMPS to the grain scale, and the conversion of discrete atomistic representations tocontinuE representations of islandsduand deposition. # 2002 Elsevier Science B.V. All rights reserved.
Optimization Framework for the Synthesis of Chemical Reactor Networks
, 1998
"... The reactor network synthesis problem involves determining the type, size, and interconnections of the reactor units, optimal concentration and temperature profiles, and the heat load requirements of the process. A general framework is presented for the synthesis of optimal chemical reactor networks ..."
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Cited by 2 (1 self)
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The reactor network synthesis problem involves determining the type, size, and interconnections of the reactor units, optimal concentration and temperature profiles, and the heat load requirements of the process. A general framework is presented for the synthesis of optimal chemical reactor networks via an optimization approach. The possible design alternatives are represented via a process superstructure which includes continuous stirred tank reactors and cross flow reactors along with mixers and splitters that connect the units. The superstructure is mathematically modeled using differential and algebraic constraints and the resulting problem is formulated as an optimal control problem. The solution methodology for addressing the optimal control formulation involves the application of a control parameterization approach where the selected control variables are discretized in terms of time invariant parameters. The dynamic system is decoupled from the optimization and solved as a func...
www.elsevier.com/locate/combustflame An adaptive reduction scheme to model reactive flow
, 2005
"... Detailed simulation of reactive flow systems using complex kinetic mechanisms consisting of hundreds of species is a computationally demanding task. In practice, to alleviate the computational complexity, the reactive flow models use a skeletal kinetic model instead of the detailed mechanism. Howeve ..."
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Detailed simulation of reactive flow systems using complex kinetic mechanisms consisting of hundreds of species is a computationally demanding task. In practice, to alleviate the computational complexity, the reactive flow models use a skeletal kinetic model instead of the detailed mechanism. However, the reduced chemistry models can accurately predict the detailed model only over a limited range of conditions. Since the reactive flow simulation encounters a broad range of conditions, using a single reduced model throughout the simulation incorporates inaccuracy into the predictive capacity of the flow model. In this paper, an adaptive scheme is presented, which aims at developing different reduced models to address the changing conditions of the flow simulation, thereby maintaining high accuracy throughout the simulation with relatively simple chemistry models. A new approach is developed for the analysis of the range of validity of the reduced model, which is highly nonconvex, for which the conventional techniques do not perform well. Finally, a procedure to implement the adaptive chemistry in different flow simulations is presented.
Stochastic algorithms for the analysis of numerical flame simulations
 J. Comput. Phys
"... Recent progress in simulation methodologies and highperformance parallel computers have made it is possible to perform detailed simulations of multidimensional reacting flow phenomena using comprehensive kinetics mechanisms. As simulations become larger and more complex, it becomes increasingly dif ..."
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Recent progress in simulation methodologies and highperformance parallel computers have made it is possible to perform detailed simulations of multidimensional reacting flow phenomena using comprehensive kinetics mechanisms. As simulations become larger and more complex, it becomes increasingly difficult to extract useful information from the numerical solution, particularly regarding the interactions of the chemical reaction and diffusion processes. In this paper we present a new diagnostic tool for analysis of numerical simulations of reacting flow. Our approach is based on recasting an Eulerian flow solution in a Lagrangian frame. Unlike a conventional Lagrangian viewpoint that follows 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 of a species that is transported through the domain by advection and diffusion. Reactions cause the atom to shift from one chemical host species to another and the subsequent transport of the atom is given by the movement of the new species. We represent these processes using a stochastic particle formulation that treats advection deterministically and models diffusion and chemistry as stochastic processes. In this
Parallel Reacting Flow Calculations for Chemical Vapor Deposition Reactor Design
 in: Proceedings of the International Conference on Computational Engineering Science
"... The MPSalsa reacting flow code has been developed at Sandia National Laboratories to compute coupled threedimensional fluid flow and detailed reaction chemistry for modeling reacting flow systems, such as Chemical Vapor Deposition (CVD) reactors. MPSalsa has been developed to take advantage of the ..."
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The MPSalsa reacting flow code has been developed at Sandia National Laboratories to compute coupled threedimensional fluid flow and detailed reaction chemistry for modeling reacting flow systems, such as Chemical Vapor Deposition (CVD) reactors. MPSalsa has been developed to take advantage of the tremendous computational speed, memory, and scalability of distributed memory parallel computers. An unstructured finite element discretization allows for the modeling of complex geometries. Complex physics for general mixtures of ideal gases, including thermal diffusion, mixture averaged and true multicomponent diffusion, variable physical properties and both gas and surface reactions can be modeled. In this brief manuscript we discuss the reacting flow model and numerical method and summarize representative calculations using MPSalsa for the CVD growth of Gallium Arsenide in a horizontal reactor with a tilted rotating substrate.
Scaling and Efficiency of PRISM in Adaptive Simulations of Turbulent Premixed Flames
"... The dominant computational cost in modeling turbulent combustion phenomena numerically with high fidelity chemical mechanisms is the time required to solve the ordinary differential equations associated with chemical kinetics. One approach to reducing that computational cost is to develop an inexpen ..."
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The dominant computational cost in modeling turbulent combustion phenomena numerically with high fidelity chemical mechanisms is the time required to solve the ordinary differential equations associated with chemical kinetics. One approach to reducing that computational cost is to develop an inexpensive surrogate model that accurately represents evolution of chemical kinetics. One such approach, PRISM, develops a polynomial representation of the chemistry evolution in a local region of chemical composition space. This representation is then stored for later use. As the computation proceeds, the chemistry evolution for other points within the same region are computed by evaluating these polynomials instead of calling an ordinary differential equation solver. If initial data for advancing the chemistry is encountered that is not in any region for which a polynomial is defined, the methodology dynamically samples that region and constructs a new representation for that region. The utility of ...
Designing Adaptive Low Dissipative High Order Schemes for Longtime Integrations
"... Classical stability and convergence theory are based on linear and local linearized analysis as the time steps and grid spacings approach zero. This theory offers no guarantee for nonlinear stability and convergence to the correct solution of the nonlinear governing equations. The use of numerical d ..."
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Classical stability and convergence theory are based on linear and local linearized analysis as the time steps and grid spacings approach zero. This theory offers no guarantee for nonlinear stability and convergence to the correct solution of the nonlinear governing equations. The use of numerical dissipation has been the key mechanism in combating numerical instabilities. Aside from acting as a postprocessor step, most filters serve as some form of numerical dissipation. Without loss of generality, “numericaldissipation/filter ” is, hereafter, referred to as “numerical dissipation”. Proper control of the numerical dissipation to accurately resolve all relevant multiscales of complex flow problems while still maintaining nonlinear stability and efficiency for longtime numerical integrations poses a great challenge to the design of numerical methods. The required type and amount of numerical dissipation are not only physical problem dependent, but also vary from one flow region to another. This is particularly true for unsteady highspeed shock/shear/boundarylayer/turbulence/acoustics interactions and/or combustion problems since the dynamics of the nonlinear effect of these flows are not wellunderstood, while longtime integrations of these flows have already stretched the limit of the current available supercomputers and the existing numerical methods. It is of paramount importance to have proper control on the type and amount of numerical dissipation in regions where it is needed but nowhere else. Inappropriate type
Development of an adaptive chemistry model considering micromixing effects
, 2003
"... In numerical simulation ofcombustion models,solution of the chemical kinical isoften the mostexpen;J; part of thecalculation sinc accurate description ofkinbO; mechanOp inhanO large nrgep of speciesan reactionT leadin to a large set of coupled ODEs,often too complex to beconTOpRkT in theirenirpJz al ..."
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In numerical simulation ofcombustion models,solution of the chemical kinical isoften the mostexpen;J; part of thecalculation sinc accurate description ofkinbO; mechanOp inhanO large nrgep of speciesan reactionT leadin to a large set of coupled ODEs,often too complex to beconTOpRkT in theirenirpJz alon with a detailed flowsimulation Henu the nep forrepresenRkT the complex chemical reaction by simple reduced models, whichcan retain connTz;;pR accuracy whilerenepkkT computationk feasibility. Realistically,unal different conentic an at different poine in time, different reaction becomeimportan; which hasbeen exploited to developan adaptive scheme such that the reducedreaction model adapts itself to thechanb#; reactorconorpkT;zz methodology is developed in this paper to con;zpRk reduced mechanJHz bysolvin an optimization problem, where the objective is todetermin theran# of conOk;bpR alon thereaction trajectory over which a prespecified nresp ofreaction can predict the actual profilewithin an allowable toleranep Suchan adaptive reducedmechanpJ isthen coupled with the reactive flow algorithm, which selectsan appropriate mechanri depennr on reactorconorpJJ an inorpJJ thecorresponkbJ ODEs for the specified valid randp These ideas are demonstrated using the mechanzp of CO=H 2 combustion in air.