Our research work is currently focused on centimeter scale combustors, usually referred to as meso-scale combustors, and delivering about 100 W of thermal power. When compared to macroscale systems the micro devices operate at lower Reynolds. Under this condition the turbulent contribution to mixing processes could be scarce or even totally absent, on the other side at the millimiter scale pure diffusive processes could be too slow to be effective. When scaling down conventional combustors the conversion of chemical energy into thermal can be severely limited by the reduction in the residence time, and in the worst case it can be totally prevented. The size reduction will imply also larger heat losses, with two main consequences: a decline in the overall combustion efficiency and a reduction of the reaction temperatures. The latter effect narrows the stability limits of the combustor by increasing the kinetic reaction times. Therefore a proper management and understanding of the thermo chemical issues connected to size reduction are mandatory in order to realize operational and efficient meso-combustors.
Experimental investigation of a mesoscale combustor
COGHE, ALDO SEBASTIANO;COZZI, FABIO;OLIVANI, ANDREA;
2006-01-01
Abstract
Our research work is currently focused on centimeter scale combustors, usually referred to as meso-scale combustors, and delivering about 100 W of thermal power. When compared to macroscale systems the micro devices operate at lower Reynolds. Under this condition the turbulent contribution to mixing processes could be scarce or even totally absent, on the other side at the millimiter scale pure diffusive processes could be too slow to be effective. When scaling down conventional combustors the conversion of chemical energy into thermal can be severely limited by the reduction in the residence time, and in the worst case it can be totally prevented. The size reduction will imply also larger heat losses, with two main consequences: a decline in the overall combustion efficiency and a reduction of the reaction temperatures. The latter effect narrows the stability limits of the combustor by increasing the kinetic reaction times. Therefore a proper management and understanding of the thermo chemical issues connected to size reduction are mandatory in order to realize operational and efficient meso-combustors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
