燃油滴於熱流場之點火研究

The Study of Droplet Ignition in a Hot Convective Environment

賈澤民(J. M. Char) ； 林琦雄(C. Y. Lin) ； 邱慶龍(C. L. Chiu)

《中國航空太空學會學刊》 26卷4期 (1994/12) Pp. 347-355

https://doi.org/10.6124/TAASRC.199412_26(4).09

摘要

經由霧化噴嘴所噴出的油霧，含有各種不同直徑的油滴，這些油滴的生命期是決定燃燒室設計的重要因素。因此對單一油滴在高溫含氧的環境中之蒸發／燃燒情形的認識，成爲很重要的課題。實際的油滴燃燒行爲是處於一對流的高溫氧化環境下進行的，因而周圍氣體與油滴的交互作用使問題變成二維以上的問題。本研究是根據簡單的點火模式，藉著改變不同的條件，了解油滴本身與外界環境對點火延遲時問的影響。由所得的結果發現，在絕大多數情況下，小尺寸油滴較易點燃，但是在較高的環境溫度下，油滴尺寸對點火延遲時問的影響反而減少，另外並比較有無外流場的情況下油滴點火延遲時間的差異。

關鍵字

油滴點火 ； 油滴燃燒

並列摘要

The fuel droplets spout from an injector nozzle contains several different sizes of diameter, and the life time of these droplets is an important factor in combustion chamber and injector design. Therefore, it is necessary to understand the vaporization I combustion behavior of a single fuel droplet in a high temperature and oxidizing environment with external flow. In real fuel spray combustor, the combustion of fuel droplets occur in a convective, high temperature, oxidizing environment and the relative motion of neighboring air turns the problems into two dimensional or more. This research with simple ignition model is to understand the effects of the fuel droplets and of the extemal environment on the ignition delay. The results indicated the droplet in smaller dimension is easier to be ignited in most cases. But in higher temperature environment, the size of fuel droplet affects the delay times less. Besides, we compared the difference of ignition delay time between external flowfield and stationary flowfield.

並列關鍵字

Droplet Ignition ； Droplet Combustion