Modeling Multi-scale Phenomena in Combustion Studies
Under certain conditions, collections of finely dispersed particles (i.e., dust clouds) can ignite and pose explosion hazards. This is a serious concern in chemical refineries, coal mines, grain elevators, and other processing facilities. A better understanding of the dynamics involved could help guide risk-reduction practices to prevent such explosions. There is also interest in harnessing the high-energy release of metals and using them as additives in solid propellants. Many combustion applications, including diesel and rocket engines and turbojets, use fuel in the form of liquid or particle spray. Understanding how these sprays combust is vital to the design and efficiency of such combustors.
Methods used to analyze spray combustion lag compared with those used to explore flame propagation in gaseous media. This is primarily due to the large number of particles involved and disparate length-scales that range from the size of the grains to the length of the combustor. During his Center appointment Professor Matalon will follow a multiscale methodology to address this complex problem. Starting with continuum equations for the separate phases, he will study the physico-chemical phenomena associated with the individual particles and then use these in the macroscopic equations to model the exchange of mass, momentum, and energy between the phases.
The project’s immediate goal is to derive models that (a) incorporate the fundamental characteristics of spray combustion and (b) can be analyzed in simple configurations. The models will describe predictive combustion properties, such as flame propagation speed, flame temperature, flammability limits, and burnout time, that can be compared to existing experimental data. The models will also elucidate much of the underlying physics essential for a complete understanding of spray combustion.