Microcombustion
Investigator: Jakub Gmurczyk


Overview

Microcombustion is a promising new field aimed at developing systems capable of propelling micro-rockets or micro-robots of the future.  Once issues of thermal quenching, mixing and heat recirculation on the “small” scale and low Reynolds numbers are well understood, smaller and more efficient devices can be developed.  Some of the methods of improving flame stability and combustion efficiency include the use of swirl and heat recirculation.
With the use of hydrocarbon fuels, energy densities orders of magnitude larger than those of modern batteries can be achieved.  Therefore a microcombustor could also be used to power portable electronics or military equipment for longer periods of time while reducing weight and increasing the power output.



Experimental Facility

A regenerative microcombustor was manufactured out of stainless steel to study the effect of heat recirculation on a premixed hydrogen flame.  The use of a quartz cap allows for optical access.  Thermocouples are used to measure the temperature of the device and of the exhaust gases. 

Results

It was observed that a relatively small number of inlet/exhaust channel windings can have a significant effect on reaction rates and flame stability.  An average flame speed of 9.1 m/s was achieved in the combustion chamber, which corresponds to roughly three times the conventional flame speed.  Stable, self-sustained combustion was achieved for long durations.
Liquid fuelled microcombustor is being developed for microthruster application.

 

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Last Edited: May 15, 2006