Combustion Science and Technology, Vol.185, No.10, 1464-1481, 2013
Miniature Fuel Film Combustor: Swirl Vane Design and Combustor Characterization
Previous research on fuel film combustors has shown their potential as portable power devices with high mass-specific and volume-specific power and energy. In this work, the addition of a swirl vane at the bottom of the film combustor, while retaining the original design of tangential fuel inlets, is presented. Two prototypes with different subcentimeter inner diameters were studied. The construction challenge of building small devices with complex geometry was met by taking advantage of rapid prototyping (three-dimensional printing techniques). The spatial resolution of the rapid prototyping technology created some limitations to the burner design. The swirl vanes were tested in subcentimeter burners, changing the metal of the chamber and investigating various chamber lengths. Operating limits and combustion stability were analyzed over a wide range of overall equivalence ratios. A general combustion assessment was completed by the measurement of flame plume length and by direct and Schlieren imaging. The effects of each swirl vane design on the combustion stability and on the air/fuel mixing behavior were studied, with the characterization of each swirl vane and combustion covering different aspects: pressure measurements, swirl number calculation and temperature profile of the wall and the flame. The results show that properly designed swirl vanes perform as effectively as tangential air injection for film combustor operation.