Prototype development of a new self-aspirating liquid-fueled microcombustor

This paper reports the development of a novel self-aspirating liquid fuel-based microcombustor with an embedded passive fuel pumping mechanism for fuel delivery. Most of the microcombustion concepts reported in the literature require auxiliary electric power for the fuel and combustion air supply, thus reducing the overall system efficiency and portability. The present work reports the development of a new hydrostatic pressure-driven liquid fuel pumping mechanism to maintain a steady and continuous fuel supply for long durations. The supply of oxidant is ensured through the natural convection of air to support the long-duration operation of the microcombustor. This helped to eliminate the requirement of a power-driven pump. The present design allows a much higher combustion efficiency and a simpler micro-combustion system, beneficial for miniaturization. The experiments reported clean and efficient combustion with a 6-17 W thermal output and less than 500 ppm CO emissions. Remarkably, no fouling or NOx emissions were detected in the exhaust gas emissions. Experimental investigations were conducted to understand the influence of hydrostatic pressure head on the flame characteristics of ethanol micro-diffusion flame. The effect of capillary diameter on flame stability, size, shape, and temperature were investigated experimentally, and the flame stabilization mechanism is discussed in the present work.