Abstract
In “KIBO” of the International Space Station, microgravity combustion experiments of a fuel droplet array were performed to investigate the interaction between flame-spread and droplet motion. The fuel droplet array consisted of 2-4 fixed droplets and movable droplets (up to 16 droplets) and was suspended on a straight SiC fiber, which enabled the movable droplets to move in the fiber direction. The initial droplet diameter of a droplet array was 1.0 mm for all tests. As a liquid fuel, n decane was employed. The first fixed-droplet was ignited by a hot wire to initiate flame-spread along a fuel droplet array. Sequential direct images and backlit images of the spreading flame and the droplet array were taken alternatively during flame-spread. A movable droplet was accelerated by the spreading flame and moved away from the neighboring burning droplet. Termination of flame-spread due to droplet motion and droplet coalescence was observed. Flame spread behavior was categorized into four typical patterns. Parameters which determine flame-spread pattern was discussed.
