A review of employed flame stabilization techniques in development of micro/mesoscale combustion-based direct energy conversion systems

This review explores advancements in flame stabilization techniques within micro/mesoscale combustion and their application in developing thermoelectric (TE) and thermophotovoltaic (TPV) systems. Micro/mesoscale combustion-driven power generation presents a viable alternative to conventional batteries for small devices, exploiting the substantially higher energy content of hydrocarbon fuels and hydrogen-almost 100 times that of modern lithium batteries. Recent shifts toward micro/mesoscale combustion-based thermoelectric (TE) and thermophotovoltaic (TPV) systems illustrate a growing preference for solid-state power conversion methods that directly transform combustion heat into electricity. These systems offer advantages over traditional technologies like micro-turbines, which suffer from mechanical and fluid-related losses. Despite promising developments, challenges remain in achieving reliable and stable micro/mesoscale combustors, crucial for efficient TE and TPV systems. Significant progress has been made in flame stabilization and combustion efficiency, critical for enhancing performance. The review discusses a range of flame stabilization strategies, from individual approaches that improve thermal and flow management within combustors to integrative techniques that combine multiple methods for synergistic benefits. Notably, use of catalyst and hydrogen blending enhance combustor stability and performance, while flow management techniques such as steps, cavities, and swirling flows increase energy conversion efficiency by ensuring more uniform heat distribution. Beyond these individual strategies, the combination of these techniques has become increasingly prevalent, offering synergistic enhancements in flame stabilization and thermal performance. Covering literature from 2000 to 2024, this paper synthesizes the current state of technology and proposes directions for future research, aiming to drive further advancements in micro/ mesoscale combustion-based power systems. This progression is aimed to support the development of nextgeneration technologies for micro-scale energy conversion.