scholarly journals Propagation of combustion waves in the shell–core energetic materials with external heat losses

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160937
Author(s):  
V. V. Gubernov ◽  
V. N. Kudryumov ◽  
A. V. Kolobov ◽  
A. A. Polezhaev
Keyword(s):  
Solid Fuel ◽  
Energetic Materials ◽  
Energetic Material ◽  
Front Propagation ◽  
Heat Losses ◽  
Combustion Waves ◽  
One Dimensional ◽  
The One ◽  
Composite Solid ◽  
Linear Stability Problem

In this paper, the properties and stability of combustion waves propagating in the composite solid energetic material of the shell–core type are numerically investigated within the one-dimensional diffusive-thermal model with heat losses to the surroundings. The flame speed is calculated as a function of the parameters of the model. The boundaries of stability are determined in the space of parameters by solving the linear stability problem and direct integration of the governing non-stationary equations. The results are compared with the characteristics of the combustion waves in pure solid fuel. It is demonstrated that a stable travelling combustion wave solution can exist for the parameters of the model for which the flame front propagation is unstable in pure solid fuel and it can propagate several times faster even in the presence of significant heat losses.

Front propagation in the one-dimensional autocatalyticA+B→2Areaction with decay

1999 ◽  
Vol 59 (3) ◽  
pp. 2561-2565 ◽  
Author(s):  
V. N. Kuzovkov ◽  
J. Mai ◽  
I. M. Sokolov ◽  
A. Blumen
Keyword(s):  
Front Propagation ◽  
One Dimensional ◽  
The One

Analysis of Normal Combustion Waves in CH4-Air System

2014 ◽  
Vol 656 ◽  
pp. 101-109 ◽  
Author(s):  
Daniel Eugeniu Crunteanu ◽  
Dan Racoti ◽  
Corneliu Berbente
Keyword(s):  
Shock Waves ◽  
Algebraic Equation ◽  
Combustion Wave ◽  
Normal Shock ◽  
Combustion Waves ◽  
Conservation Equations ◽  
One Dimensional ◽  
Air System ◽  
The One

In this study one analyses the detonation and deflagration waves starting with Euler one-dimensional conservative equations. We present two methods of computing the normal combustion waves and normal shock waves parameters. The second one, called Cpm method, uses the one dimensional conservation equations system of mass, impulse and energy reduced to an quadratic algebraic equation. Combustion wave ,in CH4-air system is presented as an application.

Microcombustors Based on Controllable Solid Fuel Elements

2003 ◽  
Author(s):  
Brian E. English ◽  
Heather H. DiBiaso ◽  
Mark G. Allen
Keyword(s):  
Solid Fuel ◽  
Reaction Times ◽  
Heat Losses ◽  
Solid Fuels ◽  
Solid Propellants ◽  
Combustion Chambers ◽  
Gas Generation ◽  
Fuel Burn ◽  
Burn Rate ◽  
Composite Solid

This paper focuses on the control of solid-fuel burn rate by controlling the solid-fuel chemistry or by controlling heat losses. Laser cutting and lamination have been used to fabricate milli-scale test structures to characterize burn rates of composite solid fuel. The base ingredients for the solid fuels tested were phase-stabilized ammonium nitrate (PSAN), ammonium perchlorate (AP), and sodium azide (SA). These base ingredients were tested alone or mixed with hydroxyl-terminated poly-butadiene (HTPB) plus various accelerants. Several experiments were performed to test the controllability of composite solid fuels. Burn-rate tests at atmospheric pressure consisted of 250 to 500 micron deep square combustion chambers packed with fuel and resistively heated on the top surface until combustion was achieved. Experiments were also performed to increase burn rate through chamber pressurization. Reaction times for a set amount of fuel were observed to increase exponentially as nozzle diameter was decreased. Finally, combustion chamber geometry was altered to control reaction propagation by increasing localized heat losses. A 500 micron thick triangular chamber was fabricated and ignited at the larger end, allowing the reaction to propagate toward the triangle tip. These results indicate that controllable actuation of solid propellants on the microscale for non-thrust, gas generation actuator applications is feasible.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

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