Progress in the Development of Chemical Kinetics Databases for the Combustion of Real Fuels

Author(s):  
Wing Tsang

Modern Computational Fluid Dynamics codes have increasing capabilities for taking into account detailed chemical kinetics [1, 2]. This opens the possibility of simulating the combustion of real fuels in industrial devices. This will bring combustion technology in line with modern developments in cutting edge science. One could not design VLSI circuits without simulations. Similarly, the design of modern airplanes depends on simulations before final wind tunnel testing. A key to the proper simulation of the chemistry in combustion is the kinetics database. The aim of this paper is to describe the current situation in this area. We will begin by discussing the special problems posed by the nature of the fuel. We will then define the elements in a proper chemical kinetic database. Currently used databases for the simulation of combustion will be critically examined. The importance of a more fundamentally based database will be emphasized. Finally some recent work pertaining to the chemical kinetics of real liquid fuel molecules will be described.

2005 ◽  
Vol 6 (5) ◽  
pp. 497-512 ◽  
Author(s):  
A Babajimopoulos ◽  
D N Assanis ◽  
D L Flowers ◽  
S M Aceves ◽  
R P Hessel

Modelling the premixed charge compression ignition (PCCI) engine requires a balanced approach that captures both fluid motion as well as low- and high-temperature fuel oxidation. A fully integrated computational fluid dynamics (CFD) and chemistry scheme (i.e. detailed chemical kinetics solved in every cell of the CFD grid) would be the ideal PCCI modelling approach, but is computationally very expensive. As a result, modelling assumptions are required in order to develop tools that are computationally efficient, yet maintain an acceptable degree of accuracy. Multi-zone models have been previously shown accurately to capture geometry-dependent processes in homogeneous charge compression ignition (HCCI) engines. In the presented work, KIVA-3V is fully coupled with a multi-zone model with detailed chemical kinetics. Computational efficiency is achieved by utilizing a low-resolution discretization to solve detailed chemical kinetics in the multi-zone model compared with a relatively high-resolution CFD solution. The multi-zone model communicates with KIVA-3V at each computational timestep, as in the ideal fully integrated case. The composition of the cells, however, is mapped back and forth between KTVA-3V and the multi-zone model, introducing significant computational time savings. The methodology uses a novel re-mapping technique that can account for both temperature and composition non-uniformities in the cylinder. Validation cases were developed by solving the detailed chemistry in every cell of a KIVA-3V grid. The new methodology shows very good agreement with the detailed solutions in terms of ignition timing, burn duration, and emissions.


Author(s):  
Aron P. Dobos ◽  
Allan T. Kirkpatrick

This paper presents an efficient approach to diesel engine combustion simulation that integrates detailed chemical kinetics into a quasidimensional fuel spray model. The model combines a discrete spray parcel concept to calculate fuel-air mixing with a detailed primary reference fuel chemical kinetic mechanism to determine species concentrations and heat release in time. Comparison of predicted pressure, heat release, and emissions with data from diesel engine experiments reported in the literature shows good agreement overall, and suggests that spray combustion processes can be predictively modeled without calibration of empirical burn rate constants at a significantly lower computational cost than standard multidimensional (CFD) tools.


2013 ◽  
Vol 390 ◽  
pp. 320-326 ◽  
Author(s):  
Chen Cheng ◽  
Fu Ting Bao ◽  
Yu Zhao ◽  
Hao Xu

A model for Premixed Ammonium Perchlorate (AP)/Hydroxyl-terminated Polybutadiene (HTPB) combustion based on detailed chemical kinetics was established on two-dimensional cylindrical coordinates using the Vorticity-Velocity formulation, finite difference methods and several essential mathematical algorithms. This model includes both solid and condensed phase combustion mechanisms and the detailed chemical kinetics of the gas phase with 37 species and 127 reactions. Results obtained from the model, such as temperature and burning rate, match data from experiments. It is found that the model established in the current study is reliable and accurate, and the Vorticity-Velocity approach combined with finite difference methods is capable of and efficient in dealing with premixed AP/HTPB combustion.


Author(s):  
Marco Antonio Nascimento ◽  
Lucilene Oliveria Rodrigues ◽  
Fagner Luis Goulart Dias

Author(s):  
A. I. Lopato ◽  
◽  
A. G. Eremenko ◽  

Recently, we developed a numerical approach for the simulation of detonation waves on fully unstructured grids and applied it to the numerical study of the mechanisms of detonation initiation in multifocusing systems. Current work is devoted to further development of our numerical approach, namely, parallelization of the numerical scheme and introduction of more comprehensive detailed chemical kinetics scheme.


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