Numerical and Experimental Studies of Mixing Enhancement and Flame Stabilization in a Meso-Scale TPV Combustor With a Porous-Medium Injector and a Heat-Regeneration Reverse Tube

Abstract

Understanding the flow dynamics, chemical kinetics, and heat transfer mechanism within a miniature thermophotovoltaic (TPV) combustor is essential for the development of devices for combustion-based power microelectromechanical systems, which may have a much higher energy density than that of conventional batteries. In this study, methods for enhancing the intensity and uniformity of the combustion chamber wall (emitter) illumination through the design of combustion and thermal management of the combustor in a miniature TPV system are proposed, discussed, and demonstrated. The proposed miniature TPV system consists of a swirling combustor with the combustion chamber wall acting as the emitter, a heat-regeneration reverse tube, and mixing-enhancing porous-medium fuel injection, which improves the low nonuniform illumination or incomplete combustion problems associated with conventional miniature TPV systems. Experiments and numerical simulations are performed to analyze the details of the flame structure and flame stabilization mechanism inside the meso-scale combustor with and without a reverse tube. Results indicate that the proposed swirling combustor with a heat-regeneration reverse tube and porous medium can improve the intensity and uniformity of the combustion chamber (emitter) illumination and can increase the surface temperature of the chamber wall. From the systematic numerical and experimental analysis, suitable operational parameters for the meso-scale TPV combustor are suggested, which may be used as a guideline for meso-scale TPV combustor design.