期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2020
卷号：4
期号：8
页码：54-65
DOI：10.15587/1729-4061.2020.208440
语种：English
出版社：PC Technology Center
摘要：Theoretically, the?combustion stability of solid fuel, which?during the combustion process?is decomposed according to the “solid phase – liquid phase –?gas” scheme, is investigated.?The physical and mathematical?models for the propagation of small perturbations?of combustion are?constructed.?The medium?in all areas of combustion and in combustion products is assumed to be incompressible, and the?viscosity of the fuel in the liquid phase is taken into account.?Thus,?perturbations of hydrodynamic parameters?are considered not only in?the two-phase?gasification zone, but also in the combustion products area and the?geometric perturbation of the instantaneous combustion front (flame), distorting the shape of its surface,?is also specified. That?is the characteristic feature of the presented physical model.?The mathematical?eigenvalue?problem is?set and solved. This problem is reduced to an algebraic?characteristic?equation for a dimensionless?complex?eigenvalue,?which positivity determines the instability.?It is proved that in the limiting case of the absence of a liquid phase, absolute instability takes place.?At the other limiting case – for perturbations?with infinite wavelength – a transition to stability takes place.?The latter fact indicates that the presence of a viscous liquid film and changes in the length of the gasification zone under the influence of perturbations have a significant stabilizing effect on solid fuel combustion. In the general case, a sufficient condition for the instability of the roots of the characteristic equation is analytically determined. The physical interpretation of the mathematical results explains the processes of autoturbulization of solid fuel combustion and the possible transition of combustion to deflagration explosion or detonation. The results of the study are in qualitative agreement with experimental data and can additionally be used for theoretical analysis of the stability of the liquid fuel combustion process in the combustion chamber.
