Micro-Combustors

Dear Colleagues,

The potential for small scale power sources based on microcombustors is great. Making use of high energy density hydrocarbon fuels (13 kWhr/kg) large scale combustion engines routinely achieve energy densities and power densities much greater than fuel cells or batteries. Combustion-based power sources can be quickly throttled to control power output. Moreover, the technologies of storing, transporting and burning liquid hydrocarbon fuels are well developed, at least on conventional scales. As attractive as these advantages are, producing small scale combustors that are robust, efficient and power dense has proven difficult. A great deal of work has been devoted to understanding the defining issues of small scale combustors and associated thermal conversion devices. However, the challenges are stiff. As combustor length scales shrink so do the residence times for fuel and oxidizer leading severe constraints on available combustion time. Likewise, reducing combustor size results in increased surface to volume ratios in micro combustors, creating difficulties with heat losses and leading to both thermal and chemical flame quenching. Finally, balance of plant issues, such as fuel storage, and delivery of fuel and combustion air become increasingly challenging as combustor size decreases. Meeting these challenges could open up many new opportunities in micropower systems.

Robert F. Richards
Guest Editor

• micro combustion
• micro power generation
• micro propulsion
• MEMS