scholarly journals A Theoretical Tool to Predict the Effects of Chemical Kinetics on Sound Propagation Within High Temperature Hydrocarbon Combustion Products

1999 ◽  
Author(s):  
Zakirul Haque ◽  
John P. Barton
Keyword(s):  
Absorption Coefficient ◽  
Sound Speed ◽  
Molecular Diffusion ◽  
Sound Propagation ◽  
Combustion Products ◽  
Viscous Stress ◽  
One Dimensional ◽  
Hydrocarbon Combustion ◽  
Diffusion Effects ◽  
Chemically Reacting

This paper involves a theoretical analysis of the propagation of sound within chemically reacting hydrocarbon combustion products. A new procedure for determining the sound speed and absorption coefficient was developed. Using a similar approach can do analyses for other chemically reacting gas mixture. One-dimensional sound propagation was assumed. Molecular diffusion effects, such as viscous stress, heat conduction, and mass diffusion were appropriately neglected along with possible effects due to vibrational non-equilibrium. In this way only the effects of chemical reactions on sound propagation was considered. The expressions for sound speed and absorption coefficient were derived as a function of frequency.

A New Method to Improve Pyrometry Results

2001 ◽  
Author(s):  
Zakirul Haque ◽  
Ziaul Huque ◽  
Md. N. Jahingir
Keyword(s):  
High Temperature ◽  
Mathematical Models ◽  
Chemical Kinetics ◽  
Sound Speed ◽  
Sound Propagation ◽  
Combustion Products ◽  
New Method ◽  
Frequency Range ◽  
Hydrocarbon Combustion ◽  
Selection Of

Abstract The paper shows how appropriate selection of the expression of sound speed as a function of temperature can improve the results obtained using acoustic pyrometers. Sound propagation within high temperature hydrocarbon combustion products was considered. Three different mathematical models for calculating sound speed were discussed. Results obtained using all three methods were presented. The paper observed that, it is important to consider the effects of chemical kinetics for a certain frequency range to obtain better results.

Comparison of Sound Propagation Characteristic between Deep and Shallow Water

2014 ◽  
Vol 577 ◽  
pp. 1198-1201
Author(s):  
Zhang Liang ◽  
Chun Xia Meng ◽  
Hai Tao Xiao
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Sound Speed ◽  
Sound Propagation ◽  
Spherical Wave ◽  
Sound Field ◽  
Propagation Loss ◽  
Speed Profile ◽  
Sound Speed Profile ◽  
Propagation Law

The physical characteristics are compared between shallow and deep water, in physics and acoustics, respectively. There is a specific sound speed profile in deep water, which is different from which in shallow water, resulting in different sound propagation law between them. In this paper, the sound field distributions are simulated under respective typical sound speed profile. The color figures of sound intensity are obtained, in which the horizontal ordinate is distance, and the vertical ordinate is depth. Then we can get some important characteristics of sound propagation. The results show that the seabed boundary is an important influence on sound propagation in shallow water, and sound propagation loss in deep water convergent zone is visibly less than which in spherical wave spreading. We can realize the remote probing using the acoustic phenomenon.

Simulation of H2-Air Turbulent Diffusion Flame by the Partial Chemical Equilibrium Method

2007 ◽  
Author(s):  
Kazui Fukumoto ◽  
Yoshifumi Ogami
Keyword(s):  
Chemical Equilibrium ◽  
Molecular Diffusion ◽  
Burning Velocity ◽  
Chemical Species ◽  
Combustion Products ◽  
Turbulent Diffusion Flame ◽  
Combustion Gases ◽  
Equilibrium Method ◽  
Dissipation Model ◽  
Partial Chemical

This paper describes an application of the partial chemical equilibrium method considered chemical kinetics in computational fluid dynamics (CFD). In this method, fuels and oxidants are mixed at a turbulent rate so that a mixture gas of fuel and oxygen is generated. Next, the mixture gas of fuel and oxygen is burnt by molecular diffusion thereby resulting in combustion gases. The turbulent mixture rate is estimated by the eddy dissipation model and the burning velocity is evaluated by the Arrhenius equation. Finally, the combustion products are calculated by the chemical equilibrium method by using the combustion gases. One of the advantages of this method is its ability to calculate the combustion products without using chemical equations. The chemical equilibrium method requires only thermo-chemical functions (specific heat, standard enthalpy, etc). This method can be applied to incinerators or some complex combustion instruments and it can predict the intermediate chemical species of dioxins, etc.

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