چكيده به لاتين
Abstract:
In this thesis, random combustion and flame propagation through organic and non-organic dust particles are studied. In this modeling two new analytical models have been have been presented. Thus, for the first time, the idea of random combustion of organic particles has been studied with conditions in which these particles sense a random temperature between ambient and flame temperature in the preheat zone. Also, in order to model random combustion in non-organic particles, it is assumed that the diameter of particles is variable and governing equations has been solved in the preheat and reaction zone. After obtaining the governing equations in each zone, then the needed boundary and matching conditions are applied in each zone. After that, these equations and the required boundary and matching conditions are simultaneously solved with the analytical model to obtain the burning and flame temperature. Thesis has been prepared in two parts. The first part (chapters 3 and 4) is devoted to model random combustion of organic particles, and the second part (chapter 5) deals with the random combustion of non-organic particles. The first chapter includes an introduction to physical and chemical properties of organic and non-organic particles, random combustion of particles and their combustion behavior. The second chapter consist of a review on literature in dust cloud combustion and random combustion in random media. The third chapter focused to model random combustion of organic particles. As shown in this chapter, the volume of evaporated particles is a function of the diameter, numerical density, and particle temperature. It is assumed that the particles vaporize first to yield a known chemical structure of gas phase. To solve the governing equations, it is considered that the flame structure consists of three zones titled the preheat-vaporization zone, the narrow reaction zone and finally the post flame zone. In the results section of this chapter, the important parameters in the propagation of flame between organic particles, including the velocity profile and flame temperature as a function of particle concentration, as well as the effect of particle diameter on burning rate and temperature have been investigated. In Chapter 4, heat loss, the heat recirculation, and the effects of non-dimensional parameters on the combustion process have been investigated. In Chapter 5, focused on modeling the random combustion of non-organic particles. As a comparison with previous studies, in this thesis a new mathematical random combustion model for organic and non-organic particles (Licopodium and Iron), also studying important parameters such as thermal resistance, Lewis's number, heat loss, and heat recirculation. The obtained results show a good compatibility with published experimental data.
Keywords: Random Combustion; Organic particles; Non-organic particles; Iron; lycopodium; Burning Velocity; Flame Temperature
