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Combustion in hydraulically resisted flows.

Gregory I. Sivashinsky (2007)

RACSAM

The effects of hydraulic resistance on premixed gas combustion in tubes and inert porous beds are discussed on the basis of recent research. It is found that the hydraulic resistance causes a gradual precompression and preheating of the unburned gas adjacent to the advancing deflagration which may lead (after an extended induction period) to a localized thermal explosion triggering an abrupt transition from deglagrative to detonative combustion. The hydraulic resistance has a profound effect also...

Comportamiento asintótico de las ecuaciones de la termoelasticidad generalizada.

Alberto Falqués Serra (1982)

Stochastica

In this paper it is first shown that the linear evolution equations for a generalized thermoelastic solid generate a C0 semigroup. Next an analysis of the long time evolution behaviour yields the some results known for classical thermoelasticity: generically, the natural state is asymptotically stable.

Computation of bifurcated branches in a free boundary problem arising in combustion theory

Olivier Baconneau, Claude-Michel Brauner, Alessandra Lunardi (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

We consider a parabolic 2D Free Boundary Problem, with jump conditions at the interface. Its planar travelling-wave solutions are orbitally stable provided the bifurcation parameter u * does not exceed a critical value u * c . The latter is the limit of a decreasing sequence ( u * k ) of bifurcation points. The paper deals with the study of the 2D bifurcated branches from the planar branch, for small k. Our technique is based on the elimination of the unknown front, turning the problem into a fully nonlinear...

Computational approaches to some inverse problems from engineering practice

Vala, Jiří (2015)

Programs and Algorithms of Numerical Mathematics

Development of engineering structures and technologies frequently works with advanced materials, whose properties, because of their complicated microstructure, cannot be predicted from experience, unlike traditional materials. The quality of computational modelling of relevant physical processes, based mostly on the principles of classical thermomechanics, is conditioned by the reliability of constitutive relations, coming from simplified experiments. The paper demonstrates some possibilities of...

Computational approaches to the design of low-energy buildings

Jarošová, Petra (2015)

Programs and Algorithms of Numerical Mathematics

European and Czech directives and technical standards, approved in several last years, force substantial changes in thermal behaviour of all buildings, including new and reconstructed one- or more-family houses, block of fl ats, etc., especially radical decrease of their energy requirements. This stimulates the development of advanced materials, structures and technologies. Since no reliable experience with their design is available, robust and non-expensive computational simulation approaches,...

Computational design optimization of low-energy buildings

Vala, Jiří (2017)

Proceedings of Equadiff 14

European directives and related national technical standards force the substantial reduction of energy consumption of all types of buildings. This can be done thanks to the massive insulation and the improvement of quality of building enclosures, using the simple evaluation assuming the one-dimensional stationary heat conduction. However, recent applications of advanced materials, structures and technologies force the proper physical, mathematical and computational analysis coming from the thermodynamic...

Computational modelling of thermal consumption of buildings with controlled interior temperature

Vala, Jiří (2017)

Programs and Algorithms of Numerical Mathematics

New materials, structures and technologies used in civil engineering impeach traditional evaluations of the annual thermal consumption of buildings, based on the quasi-stationary estimate of the thermal resistance of the building envelope, or some operational parts of such building with the guaranteed temperature. The complete proper physical analysis, applying the principles of thermodynamics and appropriate constitutive relations for particular material layers and air in rooms, is not realistic...

Conservation schemes for convection-diffusion equations with Robin boundary conditions

Stéphane Flotron, Jacques Rappaz (2013)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

In this article, we present a numerical scheme based on a finite element method in order to solve a time-dependent convection-diffusion equation problem and satisfy some conservation properties. In particular, our scheme is able to conserve the total energy for a heat equation or the total mass of a solute in a fluid for a concentration equation, even if the approximation of the velocity field is not completely divergence-free. We establish a priori errror estimates for this scheme and we give some...

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