Numerical investigations on thermal performance and flame stability of hydrogen-fueled micro tube combustor with injector for thermophotovoltaic applications.

In order to design a micro tube combustor with good thermal performance and flame stability for thermophotovoltaic applications, in this work, thermal performance and flame stability of hydrogen-fueled micro tube combustors with backward facing step and with injector are compared. It is found that the decrease of diameter ratio d 2 / d 1 leading to expansion of the symmetrical recirculation zone, which is helpful for fluid and heat circulation, and higher flame locations, which is not helpful for flame stabilization. Furthermore, effects of diameter ratio d 2 / d 1 on thermal performance and flame stability are analyzed and discussed. Results suggest that when the diameter ratio d 2 / d 1 is decreased from 0.9 to 0.8, positive effects of injector on thermal performance are enhanced and flame stability is improved under lower hydrogen/air equivalence ratio. Finally, the applications conditions of the micro tube combustor with injector are achieved. This work will provides us significant reference for designing micro tube combustor with injector. [Display omitted] • Thermal performance and flame stability of micro tube combustor with injector is investigated. • Effects of diameter ratio on the thermal performance and flame stability are revealed. • Conditions of thermal performance and flame stability enhancement are obtained. [ABSTRACT FROM AUTHOR]