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Combustion of boron particles coated with an energetic polymer material
성홍계,손영구,신원규,Doohee Han,Yohan Park,Hyungsoo Hyun 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.10
Elemental boron has attracted considerable attention as a potential high energetic material for explosives and propellants. However, its use has been hindered by its high vaporization temperature and surface oxide layer. In this study, boron particles were coated with glycidyl azide polymer (GAP) to improve their combustion characteristics. The coated particles were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy. XPS performed before and after Ar+ ion sputtering confirmed that the azide (-N3) group of GAP was positioned at the proximity of the boron surface. In addition, B@GAP particles could be decorated with metallic Ag (~10 nm) nanoparticles. The combustion characteristics were examined using a newly designed pre-heated (1,800 K) drop tube furnace and a high speed camera. Two stages of combustion were observed for a dust cloud of GAP-coated boron particles. The burning time was estimated to be approximately 37.5msec.
성홍계,김성진,염효원,허준영 한국항공우주학회 2013 International Journal of Aeronautical and Space Sc Vol.14 No.4
An assessment of two-equation turbulence models, the low Reynolds k-ε and k-ω SST models, with the compressibilitycorrections proposed by Sarkar and Wilcox, has been performed. The compressibility models are evaluated by investigatingtransonic or supersonic flows, including the arc-bump, transonic diffuser, supersonic jet impingement, and unsteadysupersonic diffuser. A unified implicit finite volume scheme, consisting of mass, momentum, and energy conservationequations, is used, and the results are compared with experimental data. The model accuracy is found to depend strongly onthe flow separation behavior. An MPI (Message Passing Interface) parallel computing scheme is implemented.