Graham Dixon-Lewis. 1 July 1922 — 5 August 2010

2012 ◽  
Vol 58 ◽  
pp. 33-53
Author(s):  
Derek Bradley
Keyword(s):  
Mathematical Modelling ◽  
Chemical Kinetics ◽  
Input Data ◽  
Laminar Flame ◽  
Hydrogen Oxidation ◽  
Turbulent Flames ◽  
Flame Structures ◽  
Kinetics Of ◽  
The Way

Graham Dixon-Lewis was a physical chemist who pioneered both experimental and mathematical studies that revealed the nature of flames. His researches, based on what was known of the chemical kinetics of hydrogen oxidation, also showed the way forward for the mathematical modelling of laminar flame structures for other fuels. These models have proved invaluable in providing the input data also for the mathematical modelling of practical turbulent flames.

Laminar flame characteristics and chemical kinetics of 2-methyltetrahydrofuran and the effect of blending with isooctane

2018 ◽  
Vol 191 ◽  
pp. 213-225 ◽  
Author(s):  
Xibin Wang ◽  
Xiangshan Fan ◽  
Kangkang Yang ◽  
Jingshan Wang ◽  
Ximing Jiao ◽  
...  
Keyword(s):  
Chemical Kinetics ◽  
Laminar Flame ◽  
Kinetics Of

scholarly journals A Neural Network-Inspired Matrix Formulation of Chemical Kinetics for Acceleration on GPUs

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2710
Author(s):  
Shivam Barwey ◽  
Venkat Raman
Keyword(s):  
Neural Network ◽  
Chemical Kinetics ◽  
Graphics Processing Units ◽  
Source Term ◽  
Turbulent Flames ◽  
Peak Performance ◽  
Computational Time ◽  
Detailed Chemical Kinetics ◽  
The Matrix ◽  
Artificial Neural

High-fidelity simulations of turbulent flames are computationally expensive when using detailed chemical kinetics. For practical fuels and flow configurations, chemical kinetics can account for the vast majority of the computational time due to the highly non-linear nature of multi-step chemistry mechanisms and the inherent stiffness of combustion chemistry. While reducing this cost has been a key focus area in combustion modeling, the recent growth in graphics processing units (GPUs) that offer very fast arithmetic processing, combined with the development of highly optimized libraries for artificial neural networks used in machine learning, provides a unique pathway for acceleration. The goal of this paper is to recast Arrhenius kinetics as a neural network using matrix-based formulations. Unlike ANNs that rely on data, this formulation does not require training and exactly represents the chemistry mechanism. More specifically, connections between the exact matrix equations for kinetics and traditional artificial neural network layers are used to enable the usage of GPU-optimized linear algebra libraries without the need for modeling. Regarding GPU performance, speedup and saturation behaviors are assessed for several chemical mechanisms of varying complexity. The performance analysis is based on trends for absolute compute times and throughput for the various arithmetic operations encountered during the source term computation. The goals are ultimately to provide insights into how the source term calculations scale with the reaction mechanism complexity, which types of reactions benefit the GPU formulations most, and how to exploit the matrix-based formulations to provide optimal speedup for large mechanisms by using sparsity properties. Overall, the GPU performance for the species source term evaluations reveals many informative trends with regards to the effect of cell number on device saturation and speedup. Most importantly, it is shown that the matrix-based method enables highly efficient GPU performance across the board, achieving near-peak performance in saturated regimes.

Atomic-level insight into reasonable design of metal-based catalysts for hydrogen oxidation in alkaline electrolytes

2021 ◽  
Author(s):  
Lulu An ◽  
Xu Zhao ◽  
Tonghui Zhao ◽  
Deli Wang
Keyword(s):  
Fuel Cell ◽  
Anion Exchange ◽  
Hydrogen Oxidation ◽  
Anion Exchange Membrane ◽  
Atomic Level ◽  
Alkaline Electrolytes ◽  
Exchange Membrane ◽  
Kinetics Of ◽  
Insight Into ◽  
Hydrogen Utilization

Anion exchange membrane fuel cell (AEMFC) is becoming highly attractive for hydrogen utilization owing to the advantages of employing economic catalysts in alkaline electrolytes. Nevertheless, the kinetics of anodic hydrogen...

CHEMICAL KINETICS OF WEATHERING IN YOUNG ANDISOLS FROM NORTHEASTERN JAPAN USING SOIL AGE NORMALIZED TO 10°C

Soil Science ◽  
1993 ◽  
Vol 155 (1) ◽  
pp. 53-60 ◽  
Author(s):  
SADAO SHOJI ◽  
MASAMI NANZYO ◽  
YASUHITO SHIRATO ◽  
TOYOAKI ITO
Keyword(s):  
Chemical Kinetics ◽  
Northeastern Japan ◽  
Soil Age ◽  
Kinetics Of

The Influence of Singlet Oxygen and Ozone on the Combustion in Methane-Air Mixture

2013 ◽  
Vol 699 ◽  
pp. 111-118
Author(s):  
Rui Shi ◽  
Chang Hui Wang ◽  
Yan Nan Chang
Keyword(s):  
Singlet Oxygen ◽  
Chemical Kinetics ◽  
Mole Fraction ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Laminar Flame ◽  
Combustion Products ◽  
Flame Speed ◽  
Air Mixing

Based on GRI3.0, we study the main chemical kinetics process about reactions of singlet oxygen O2(a1Δg) and ozone O3 with methane-air combustion products, inherit and further develop research in chemical kinetics process with enhancement effects on methane-air mixed combustion by these two molecules. In addition, influence of these two molecules on ignition delay time and flame speed of laminar mixture are considered in our numerical simulation research. This study validates the calculation of this model which cotains these two active molecules by using experimental data of ignition delay time and the speed of laminar flame propagation. In CH4-air mixing laminar combustion under fuel-lean condition(ф=0.5), flame speed will be increased, and singlet oxygen with 10% of mole fraction increases it by 80.34%, while ozone with 10% mole fraction increase it by 127.96%. It mainly because active atoms and groups(O, H, OH, CH3, CH2O, CH3O, etc) will be increased a lot after adding active molecules in the initial stage, and chain reaction be reacted greatly, inducing shortening of reaction time and accelerating of flame speed. Under fuel rich(ф=1.5), accelerating of flame speed will be weakened slightly, singlet oxygen with 10% in molecular oxygen increase it by 48.93%, while ozone with 10% increase it by 70.25%.

Vulcanization of Elastomers. 23. The Chemical Kinetics of Vulcanization Reactions and The Physical Properties of The Vulcanizates. I

1960 ◽  
Vol 33 (2) ◽  
pp. 335-341
Author(s):  
Walter Scheele ◽  
Karl-Heinz Hillmer
Keyword(s):  
Activation Energy ◽  
Physical Properties ◽  
Chemical Kinetics ◽  
Kcal Mole ◽  
First Order ◽  
Equilibrium Swelling ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization ◽  
Limiting Value ◽  
Good Agreement

Abstract As a complement to earlier investigations, and in order to examine more closely the connection between the chemical kinetics and the changes with vulcanization time of the physical properties in the case of vulcanization reactions, we used thiuram vulcanizations as an example, and concerned ourselves with the dependence of stress values (moduli) at different degrees of elongation and different vulcanization temperatures. We found: 1. Stress values attain a limiting value, dependent on the degree of elongation, but independent of the vulcanization temperature at constant elongation. 2. The rise in stress values with the vulcanization time is characterized by an initial delay, which, however, is practically nonexistent at higher temperatures. 3. The kinetics of the increase in stress values with vulcanization time are both qualitatively and quantitatively in accord with the dependence of the reciprocal equilibrium swelling on the vulcanization time; both processes, after a retardation, go according to the first order law and at the same rate. 4. From the temperature dependence of the rate constants of reciprocal equilibrium swelling, as well as of the increase in stress, an activation energy of 22 kcal/mole can be calculated, in good agreement with the activation energy of dithiocarbamate formation in thiuram vulcanizations.

Sign in / Sign up

Export Citation Format

Share Document