Online, spatiotemporally resolved characterization of aluminum atom puffing during the ignition of micron-sized aluminum wire

This paper presents the first online, in-situ experimental evidence of the puffing behavior of aluminium (Al) atoms during the ignition of a micron-sized Al wire. As the protective alumina (Al 2 O 3 ) layer ruptures, spatially resolved laser absorption measurements reveal the outward puffing of Al atoms from the molten Al wire core. These Al atoms then react with the surrounding oxidizers, leading to the formation of the visible Al 2 O 3 particle condensation layer. Moreover, these Al atoms exhibit an expanding velocity that surpasses that of the impinging bulk gases, allowing them to distribute beyond the Al 2 O 3 particle condensation layer under fuel rich conditions.