In the text, we used equivalent shallow water model and truncated model method to analyse the stability of the jet, and pointed out the conditions of the appearing of instable wave.
本文应用等值浅水模式，采用截断模方法，分析了急流的稳定性，并给出急流上不稳定波出现的条件。
2
Jet flame of the ignition that is usually used in the work is calculated by the difference. And the analysis on the flame stability is given.
用差分法计算了工程上最常用的点火器的射流火焰，并给出火焰稳定性的分析。
3
Analyszed the stability and movement form of jet in the air by using the jet fragmentation theory, and studied the jet droplets broken way.