چكيده به لاتين
Abstract
The major part of the world's energy consumption is provided from fossil fuels which this energy conversion is done through direct burning of solid or heavy liquid fuels in air. The small particle size, increases the contact area of the fuel particls with air and as a result, each component reaches the gas phase with a less energy intake. Furthermore, taking the advantage of the significant potential of the energy release of metal particles combustion or in other words, the development of new energitic materials such as; metallic fuels in advanced propulsion systems to increase the combustion efficiency, all remark the importance of combustible metal particles like aluminum. Therefore, in this doctoral thesis, efforts have been made to emphasize the discrete combustion of aluminum dust particles.
This thesis has investigated the pulsating flame. This complicated phenomenon is not fully discovered. This investigation is based on a thermal modeling of the conduction and the radiation heat transfer in a dust combustion process. In this mathematical modeling, the burning particles are as the heat sources which effect their ambient by the conduction and the radiation heat transfer. The aim of this study is to present a comprehensive model for analyzing the processes involved in the discrete combustion of aluminum particles. At first, combustion of a single aluminum particle was studied.Then, modeling discrete combustion of aluminum dust particles is investigated with reasonable assumptions. Radiation is one of the most important factors that will be studied. Afterwards, with the consideration of random distribution of fuel particles in a reaction medium, the random combustion of aluminum dust cloud is researched. In the following, the quenching distance of aluminum dust flame in narrow channels is studied. Finally, combustion phenomena of aluminum dust cloud in a counterflow configuration with rational assumptions is investigated. In this analysis, dust flame’s dynamic parameters such as; Flame propagation speed, Minimum ignition energy, Quenching distance, Flame location and etc. are studied in a discrete combustion mechanisim.
Keywords: Discrete combustion, Quenching distance, Random combustion, Flame propagation Speed, Minimum Ignition Energy, Counterflow combustion, Metals ignition.
