Understanding Breakthrough of the Chemical Kinetics for Plasma in Liquid: Reaction Mechanism of Ethanol Reforming in Microwave Discharge

2021 ◽  
Author(s):  
Jing-Lin Liu ◽  
Tong-Hui Zhu ◽  
Bing Sun
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Microwave Discharge ◽  
Ethanol Reforming ◽  
Liquid Reaction ◽  
Plasma In Liquid

Computationally Efficient Simulation of Multi-Component Fuel Combustion Using a Sparse Analytical Jacobian Chemistry Solver and High-Dimensional Clustering

2013 ◽  
Author(s):  
Federico Perini ◽  
Anand Krishnasamy ◽  
Youngchul Ra ◽  
Rolf D. Reitz
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Point Of View ◽  
High Dimensional ◽  
Computational Point ◽  
Fuel Surrogates

The need for more efficient and environmentally sustainable internal combustion engines is driving research towards the need to consider more realistic models for both fuel physics and chemistry. As far as compression ignition engines are concerned, phenomenological or lumped fuel models are unreliable to capture spray and combustion strategies outside of their validation domains — typically, high-pressure injection and high-temperature combustion. Furthermore, the development of variable-reactivity combustion strategies also creates the need to model comprehensively different hydrocarbon families even in single fuel surrogates. From the computational point of view, challenges to achieving practical simulation times arise from the dimensions of the reaction mechanism, that can be of hundreds species even if hydrocarbon families are lumped into representative compounds, and thus modeled with non-elementary, skeletal reaction pathways. In this case, it is also impossible to pursue further mechanism reductions to lower dimensions. CPU times for integrating chemical kinetics in internal combustion engine simulations ultimately scale with the number of cells in the grid, and with the cube number of species in the reaction mechanism. In the present work, two approaches to reduce the demands of engine simulations with detailed chemistry are presented. The first one addresses the demands due to the solution of the chemistry ODE system, and features the adoption of SpeedCHEM, a newly developed chemistry package that solves chemical kinetics using sparse analytical Jacobians. The second one aims to reduce the number of chemistry calculations by binning the CFD cells of the engine grid into a subset of clusters, where chemistry is solved and then mapped back to the original domain. In particular, a high-dimensional representation of the chemical state space is adopted for keeping track of the different fuel components, and a newly developed bounding-box-constrained k-means algorithm is used to subdivide the cells into reactively homogeneous clusters. The approaches have been tested on a number of simulations featuring multi-component diesel fuel surrogates, and different engine grids. The results show that significant CPU time reductions, of about one order of magnitude, can be achieved without loss of accuracy in both engine performance and emissions predictions, prompting for their applicability to more refined or full-sized engine grids.

scholarly journals Hydrogen Production from Ethanol Reforming by a Microwave Discharge Using Air as a Working Gas

ACS Omega ◽  
2021 ◽  
Author(s):  
Wei Guo ◽  
XianFeng Zheng ◽  
ZhengBo Qin ◽  
QiJia Guo ◽  
Lei Liu
Keyword(s):  
Hydrogen Production ◽  
Microwave Discharge ◽  
Ethanol Reforming

scholarly journals Intersections and coincidences in chemical kinetics: Linear two-step reversible–irreversible reaction mechanism

2013 ◽  
Vol 65 (10) ◽  
pp. 1614-1624 ◽  
Author(s):  
D. Constales ◽  
G.S. Yablonsky ◽  
G.B. Marin
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Irreversible Reaction

In-situ FTIR study of reaction mechanism and chemical kinetics of a Xundian lignite during non-isothermal low temperature pyrolysis

2016 ◽  
Vol 124 ◽  
pp. 180-188 ◽  
Author(s):  
Zhiyuan Niu ◽  
Guijian Liu ◽  
Hao Yin ◽  
Chuncai Zhou ◽  
Dun Wu ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Low Temperature ◽  
Chemical Kinetics ◽  
In Situ Ftir ◽  
Ftir Study ◽  
Low Temperature Pyrolysis ◽  
Kinetics Of

Computationally Efficient Simulation of Multicomponent Fuel Combustion Using a Sparse Analytical Jacobian Chemistry Solver and High-Dimensional Clustering

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Federico Perini ◽  
Anand Krishnasamy ◽  
Youngchul Ra ◽  
Rolf D. Reitz
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
High Dimensional ◽  
Processing Unit ◽  
Computational Point ◽  
Central Processing ◽  
Fuel Surrogates

The need for more efficient and environmentally sustainable internal combustion engines is driving research towards the need to consider more realistic models for both fuel physics and chemistry. As far as compression ignition engines are concerned, phenomenological or lumped fuel models are unreliable to capture spray and combustion strategies outside of their validation domains—typically, high-pressure injection and high-temperature combustion. Furthermore, the development of variable-reactivity combustion strategies also creates the need to model comprehensively different hydrocarbon families even in single fuel surrogates. From the computational point of view, challenges to achieving practical simulation times arise from the dimensions of the reaction mechanism, which can be of hundreds species even if hydrocarbon families are lumped into representative compounds and, thus, modeled with nonelementary, skeletal reaction pathways. In this case, it is also impossible to pursue further mechanism reductions to lower dimensions. central processing unit (CPU) times for integrating chemical kinetics in internal combustion engine simulations ultimately scale with the number of cells in the grid and with the cube number of species in the reaction mechanism. In the present work, two approaches to reduce the demands of engine simulations with detailed chemistry are presented. The first one addresses the demands due to the solution of the chemistry ordinary differential equation (ODE) system, and features the adoption of SpeedCHEM, a newly developed chemistry package that solves chemical kinetics using sparse analytical Jacobians. The second one aims to reduce the number of chemistry calculations by binning the computational fluid dynamics (CFD) cells of the engine grid into a subset of clusters, where chemistry is solved and then mapped back to the original domain. In particular, a high-dimensional representation of the chemical state space is adopted for keeping track of the different fuel components, and a newly developed bounding-box- constrained k-means algorithm is used to subdivide the cells into reactively homogeneous clusters. The approaches have been tested on a number of simulations featuring multicomponent diesel fuel surrogates and different engine grids. The results show that significant CPU time reductions, of about 1 order of magnitude, can be achieved without loss of accuracy in both engine performance and emissions predictions, prompting for their applicability to more refined or full-sized engine grids.

The electric oxygen-iodine laser: chemical kinetics of O 2 (a1Δ) production and I(2P 1/2 ) excitation in microwave discharge systems

2006 ◽  
Author(s):  
W. T. Rawlins ◽  
S. Lee ◽  
W. J. Kessler ◽  
D. B. Oakes ◽  
L. G. Piper ◽  
...  
Keyword(s):  
Chemical Kinetics ◽  
Microwave Discharge ◽  
Iodine Laser ◽  
Kinetics Of

Degradation of Methylene Blue by Microwave Discharge Plasma in Liquid

2013 ◽  
Vol 53 (9) ◽  
pp. 697-702 ◽  
Author(s):  
Bo Wang ◽  
Bing Sun ◽  
Xiaomei Zhu ◽  
Zhiyu Yan ◽  
Yongjun Liu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Discharge Plasma ◽  
Microwave Discharge ◽  
Plasma In Liquid

Introduction

2006 ◽  
Author(s):  
John Ross ◽  
Igor Schreiber ◽  
Marcel O. Vlad
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Chemical Engineering ◽  
Reaction Pathway ◽  
Reaction System ◽  
Chemical Species ◽  
Pulse Method ◽  
Elementary Reaction ◽  
Elementary Reactions ◽  
Arbitrary Strength

Chemical kinetics as a science has existed for more than a century. It deals with the rates of reactions and the details of how a given reaction proceeds from reactants to products. In a chemical system with many chemical species, there are several questions to be asked: What species react with what other species? In what temporal order? With what catalysts? And with what results? The answers constitute the macroscopic reaction mechanism. The process can be described macroscopically by listing the reactants, intermediates, products, and all the elementary reactions and catalysts in the reaction system. The present book is a treatise and text on the determination of complex reaction mechanisms in chemistry and in chemical reaction systems that occur in chemical engineering, biochemistry, biology, biotechnology, and genomics. A basic knowledge of chemical kinetics is assumed. Several approaches are suggested for the deduction of information on the causal chemical connectivity of the species, on the elementary reactions among the species, and on the sequence of the elementary reactions that constitute the reaction pathway and the reaction mechanism. Chemical reactions occur by the collisions of molecules, and such an event is called an elementary reaction for specified reactant and product molecules. A balanced stoichiometric equation for an elementary reaction yields the number of each type of molecule according to conservation of atoms, mass, and charge. Figure 1.1 shows a relatively simple reaction mechanism for the decomposition of ozone by light, postulated to occur in a series of three elementary steps. (The details of collisions of molecules and bond rearrangements are not discussed.) All approaches are based on the measurements of the concentrations of chemical species in the whole reaction system, not on parts, as has been the practice. One approach is called the pulse method, in which a pulse of concentration of one or more species of arbitrary strength is applied to a reacting system and the responses of as many species as possible are measured. From these responses causal chemical connectivities may be inferred. The basic theory is explained, demonstrated on a model mechanism, and tested in an experiment on a part of glycolysis.

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