Numerical Simulation of the Ram Accelerator Using a New Chemical Kinetics Mechanism

2002 ◽  
Vol 18 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Michael J. Nusca
Keyword(s):  
Numerical Simulation ◽  
Chemical Kinetics ◽  
Ram Accelerator

WET BURNING – THE MODERN TREND IN ENVIRONMENTAL BENIGN FUEL COMBUSTION AND IN SOLUTION TO THE PROBLEM OF SUSTAINABLE DEVELOPMENT OF THE POWER GENERATION

2018 ◽  
pp. 96-117 ◽  
Author(s):  
B. S. Soroka
Keyword(s):  
Numerical Simulation ◽  
Nitrogen Oxides ◽  
Chemical Kinetics ◽  
Fuel Combustion ◽  
Transport Processes ◽  
Cfd Modeling ◽  
Furnace Chamber ◽  
Modern Trend ◽  
Atmospheric Air ◽  
No Formation

The article considers the role and place of water and water vapor in combustion processes with the purpose of reduction the effluents of nitrogen oxides and carbon oxide. We have carried out the complex of theoretical and computational researches on reduction of harmful nitrogen and carbon oxides by gas fuel combustion in dependence on humidity of atmospheric air by two approaches: CFD modeling with attraction of DRM 19 chemical kinetics mechanism of combustion for 19 components along with Bowman’s mechanism used as “postprocessor” to determine the [NO] concentration; different thermodynamic models of predicting the nitrogen oxides NO formation. The numerical simulation of the transport processes for momentum, mass and heat being solved simultaneously in the united equations’ system with the chemical kinetics equations in frame of GRI methane combustion mechanism and NO formation calculated afterwards as “postprocessor” allow calculating the absolute actual [CO] and [NO] concentrations in dependence on combustion operative conditions and on design of furnace facilities. Prediction in frame of thermodynamic equilibrium state for combustion products ensures only evaluation of the relative value of [NO] concentration by wet combustion the gas with humid air regarding that in case of dry air – oxidant. We have developed the methodology and have revealed the results of numerical simulation of impact of the relative humidity of atmospheric air on harmful gases formation. Range of relative air humidity under calculations of atmospheric air under impact on [NO] and [CO] concentrations at the furnace chamber exit makes φ = 0 – 100%. The results of CFD modeling have been verified both by author’s experimental data and due comparing with the trends stated in world literature. We have carried out the complex of the experimental investigations regarding atmospheric air humidification impact on flame structure and environmental characteristics at natural gas combustion with premixed flame formation in open air. The article also proposes the methodology for evaluation of the nitrogen oxides formation in dependence on moisture content of burning mixture. The results of measurements have been used for verification the calculation data. Coincidence of relative change the NO (NOx) yield due humidification the combustion air revealed by means of CFD prediction has confirmed the qualitative and the quantitative correspondence of physical and chemical kinetics mechanisms and the CFD modeling procedures with the processes to be studied. A sharp, more than an order of reduction in NO emissions and simultaneously approximately a two-fold decrease in the CO concentration during combustion of the methane-air mixture under conditions of humidification of the combustion air to a saturation state at a temperature of 325 K.

scholarly journals A modification of the CABARET scheme for numerical simulation of one-dimensional detonation flows using a one-stage irreversible model of chemical kinetics

2017 ◽  
pp. 1-10
Author(s):  
А.В. Данилин ◽  
А.В. Соловьев ◽  
А.М. Зайцев
Keyword(s):  
Numerical Simulation ◽  
Chemical Kinetics ◽  
Order Of Approximation ◽  
Governing Equations ◽  
Physical Processes ◽  
Cabaret Scheme ◽  
One Dimensional ◽  
One Stage ◽  
The Right ◽  
Made In

Представлен алгоритм для численного моделирования задач одномерной детонации с использованием одностадийной необратимой модели химической кинетики. Дискретизация уравнений движения произведена согласно балансно-характеристической методике ``кабаре''. Аппроксимация источниковых членов выполнена без расщепления по физическим процессам с использованием неявного подхода с регулируемым порядком аппроксимации. Показано точное согласование параметров моделируемой детонации Чепмена--Жуге с аналитическим решением. Для неустойчивой детонации продемонстрирована зависимость результатов расчета от порядка аппроксимации правых частей. An algorithm for numerical simulation of one-dimensional detonation using a one-stage irreversible model of chemical kinetics is proposed. The discretization of the convective parts of governing equations is made in accordance with the balance-characteristic CABARET (Compact Accurately Boundary Adjusting-REsolution Technique) approach. The approximation of source terms is performed implicitly without splitting into physical processes with a regulated order of approximation. It is shown that the numerically obtained Chapman-Jouget detonation parameters are in exact agreement with the analytical solution. It is also shown that, in the case of unstable detonation, the numerical results are dependent on the order of approximation chosen for the right-hand sides of the governing equations.

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