Thermal explosion characteristics of a combustible gas containing fuel droplets

2021 ◽  
Vol 13 (2-3) ◽  
pp. 124-145
Author(s):  
Saad A. El-Sayed
Keyword(s):  
Thermal Explosion ◽  
Numerical Solutions ◽  
Exothermic Reaction ◽  
Single Step ◽  
Critical Conditions ◽  
Phase System ◽  
Characteristic Parameters ◽  
Fuel Droplets ◽  
Spray System ◽  
Combustible Gas

This paper investigated the critical ignition conditions of combustible gas containing liquid fuel droplets. The analysis is done based on the criteria of the thermal explosion theory. It includes analytical and numerical solutions of modeling equations of fuel droplets heating and evaporation by convection and radiation from the surrounding reactive hot gas. The exothermic reaction is usually modeled as a single-step reaction obeying an Arrhenius temperature dependence. The thermal conductivity of the fuel droplet is dependent on temperature. The analytical solution produced relations between the main critical characteristic parameters in all planes of the solution. The results obtained from investigating the effect of the characteristic parameters on the explosion behavior of gas and fuel droplets and the thermal radiation proved that both of them are significant. The study proved that the criticality definitions of the thermal explosion of a single-phase system can be used effectively and efficiently to determine the critical conditions of a multi-phase system. Finally, the application of the numerical solutions of the modeling equations was used to analyze the explosion characteristics of a diesel fuel spray system.

scholarly journals Studies on the Effects of Interphase Heat Exchange during Thermal Explosion in a Combustible Dusty Gas with General Arrhenius Reaction-Rate Laws

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
K. S. Adegbie ◽  
F. I. Alao
Keyword(s):  
Heat Exchange ◽  
Thermal Explosion ◽  
Reaction Rate ◽  
Numerical Solutions ◽  
Combustion Process ◽  
Solid Particles ◽  
Dusty Gas ◽  
Rate Laws ◽  
Fuel Droplets ◽  
Interphase Heat Exchange

A mathematical model for thermal explosion in a combustible dusty gas containing fuel droplets with general Arrhenius reaction-rate laws, convective and radiative heat losses, and interphase heat exchange between gas and inert solid particles is investigated. The objective of the study is to examine the effects of interphase heat exchange between the gas and solid particles on (i) ignition of reacting gas, (ii) accumulation of heat by the solid particles during combustion process (iii) evaporation of the liquid fuel droplets, and (iv) consumption of reacting gas concentration. The equations governing the physical model with realistic assumptions are stated and nondimensionalised leading to an intractable system of first-order coupled nonlinear differential equations, which is not amenable to exact methods of solution. Therefore, we present numerical solutions as well as different qualitative effects of varying interphase heat exchange parameter. Graphs and Table feature prominently to explain the results obtained.

Thermal explosion in a combustible gas containing fuel droplets

1998 ◽  
Vol 2 (2) ◽  
pp. 153-165 ◽  
Author(s):  
A C Mcintosh ◽  
V Gol'dshtein ◽  
I Goldfarb ◽  
A Zinoviev
Keyword(s):  
Thermal Explosion ◽  
Fuel Droplets ◽  
Combustible Gas

Dynamic Antiplane Interaction of Subsurface Circular Cavities in a Semi-Infinite Piezoelectric Medium

2009 ◽  
Author(s):  
Tianshu Song ◽  
Tamman Merhej ◽  
Qingna Shang ◽  
Dong Li
Keyword(s):  
Stress Concentration ◽  
Dynamic Stress ◽  
Numerical Solutions ◽  
Piezoelectric Medium ◽  
Dynamic Stress Concentration ◽  
Characteristic Parameters ◽  
Time Harmonic ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Piezoelectric Characteristic

In the present work, dynamic interaction is investigated theoretically between several circular cavities near the surface in a semi-infinite piezoelectric medium subjected to time-harmonic incident anti-plane shearing. The analyses are based upon the use of complex variable and multi coordinates. Dynamic stress concentration factors at the edges of the subsurface circular cavities are obtained by solving boundary value problems with the method of orthogonal function expansion. Some numerical solutions about two interacting subsurface circular cavities in a semi-infinite piezoelectric medium are plotted so as to show how the frequencies of incident wave, the piezoelectric characteristic parameters of the material and the structural geometries influence on the dynamic stress concentration factors.

Formulation of a General Multiphase, Multicomponent Chemical Flood Model

1981 ◽  
Vol 21 (01) ◽  
pp. 63-76 ◽  
Author(s):  
Paul D. Fleming ◽  
Charles P. Thomas ◽  
William K. Winter
Keyword(s):  
Phase Equilibrium ◽  
Arbitrary Number ◽  
Numerical Solutions ◽  
Field Tests ◽  
Reservoir Rock ◽  
Phase System ◽  
Surfactant Flooding ◽  
Two Phase ◽  
Special Cases ◽  
Flood Model

Abstract A general multiphase, multicomponent chemical flood model has been formulated. The set of mass conservation laws for each component in an isothermal system is closed by assuming local thermodynamic (phase) equilibrium, Darcy's law for multiphase flow through porous media, and Fick's law of diffusion. For the special case of binary, two-phase flow of nonmixing incompressible fluids, the equations reduce to those of Buckley and Leverett. The Buckley-Leverett equations also may be obtained for significant fractions of both components in the phases if the two phases are sufficiently incompressible. To illustrate the usefulness of the approach, a simple chemical flood model for a ternary, two-phase system is obtained which can be applied to surfactant flooding, polymer flooding, caustic flooding, etc. Introduction Field tests of various forms of surfactant flooding currently are under way or planned at a number of locations throughout the country.1 The chemical systems used have become quite complicated, often containing up to six components (water, oil, surfactant, alcohol, salt, and polymer). The interactions of these components with each other and with the reservoir rock and fluids are complex and have been the subject of many laboratory investigations.2–22 To aid in organizing and understanding laboratory work, as well as providing a means of extrapolating laboratory results to field situations, a mathematical description of the process is needed. Although it seems certain that mathematical simulations of such processes are being performed, models aimed specifically at the process have been reported only recently in the literature.23–31 It is likely that many such simulations are being performed on variants of immiscible, miscible, and compositional models that do not account for all the facets of a micellar/polymer process. To help put the many factors of such a process in proper perspective, a generalized model has been formulated incorporating an arbitrary number of components and an arbitrary number of phases. The development assumes isothermal conditions and local phase equilibrium. Darcy's law32,33 is assumed to apply to the flow of separate phases, and Fick's law34 of diffusion is applied to components within a phase. The general development also provides for mass transfer of all components between phases, the adsorption of components by the porous medium, compressibility, gravity segregation effects, and pressure differences between phases. With the proper simplifying assumptions, the general model is shown to degenerate into more familiar special cases. Numerical solutions of special cases of interest are presented elsewhere.35

Critical Conditions of Thermal Explosion Considering Space-Temporal Nonlocality

2018 ◽  
Vol 61 (2) ◽  
pp. 252-256
Author(s):  
V. A. Kudinov ◽  
A. V. Eremin ◽  
I. V. Kudinov ◽  
V. V. Zhukov
Keyword(s):  
Thermal Explosion ◽  
Critical Conditions

Thermal radiation effect on thermal explosion in gas containing fuel droplets

1999 ◽  
Vol 3 (4) ◽  
pp. 769-787 ◽  
Author(s):  
Igor Goldfarb ◽  
Vladimir Gol'dshtein ◽  
Grigory Kuzmenko ◽  
Sergei Sazhin
Keyword(s):  
Thermal Radiation ◽  
Thermal Explosion ◽  
Radiation Effect ◽  
Fuel Droplets ◽  
Thermal Radiation Effect

Critical conditions of thermal explosion of a porous layer

2008 ◽  
Vol 44 (3) ◽  
pp. 291-299 ◽  
Author(s):  
R. S. Burkina ◽  
V. G. Prokof’ev
Keyword(s):  
Thermal Explosion ◽  
Porous Layer ◽  
Critical Conditions
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