本研究的主題在產製單核的氣-油複合液滴，觀察其燃燒特性，並與單質液滴的燃燒特性做比較。氣-油複合液滴之產製採用同心管，內管通氣體，外管通液體，而複合液柱的噴嘴設計有外凸型、齊平型與內縮型三種，其中外凸型的噴嘴設計之複合液柱最為穩定。當複合液柱的氣泡頻率與雷利不穩定性(Rayleigh instability)一致時可形成氣-油複合液滴。複合液滴的外徑約為噴嘴尺寸的1.8倍，且複合液滴的內外徑比是氣-油速度比的函數。複合液滴的燃燒可分為複合液滴的爆裂噴發與單質液滴燃燒兩部份。當複合液滴進入高溫環境後會迅速爆裂洩出氣體，並形成液體噴柱，液體噴柱會進一步斷裂成小液滴，每顆複合液滴僅爆裂一次，從爆裂到噴柱形成前的時間約 ，複合液滴的爆裂與噴發行為不受環境溫度與包覆氣體種類的影響。單質液滴燃燒的蒸發速率常數隨環境氧濃度的提高而增加，本研究中實驗蒸發速率常數與半經驗公式值相近。

In this study, a gas-in-oil compound drop was generated, and its burning characteristics were compared with those of a single-phase drop. Three types of coaxial nozzle were designed and investigated in this study, and we found that the nozzle with a protruding inner tube is the best design for the production of compound drops. The compound jet exhibited two modes: bubbling jet and compound drop. Compound drops were generated while the frequency of bubbles matched Rayleigh instability of the jet. The outer diameter of compound drop was about 1.8 times of the inner diameter of the outer tube, and the ratios of inner and outer diameter of the compound drop depended only on the core-to-shell velocity ratios. The burning of a gas-in-oil compound drop could be separated into two stages: rupturing of the compound drop and burning of single-phase drop. After entering high temperature surrounding, the compound drop would rupture and release the gas immediately just one time within . Rupturing of compound drop was independent of the surrounding temperature and the trapped gas. The evaporation rate constant of the burning single-phase drop increased with the fraction of oxygen in the surrounding, and the experimental evaporation rate constants matched the semi-theoretical results well.

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