Comparison of combustion efficiency between micro combustors with single- and double-layered walls: A numerical study

In this study, a micro combustor with double-layered walls was proposed for micro energy and power systems. SiC and quartz were selected for the inner and outer layers of combustor walls, respectively. Numerical investigation demonstrates that the double-layered micro combustor can achieve a higher combustion efficiency at large inlet velocity than single-layered SiC and quartz micro combustors. It is revealed that the heat recirculation effect of double-layered micro combustor is greatly enhanced compared to quartz combustor; meanwhile, the heat loss rate is decreased to some extent compared to SiC combustor. Moreover, the negative stretch effect at flame tip is reduced in the double-layered combustor. Consequently, combustion process can be intensified and flame tip opening can be alleviated, leading to a higher combustion efficiency in the double-layered micro combustor.