水下超声速燃气射流动力学特性研究

Research on dynamic characteristics of underwater superasonic gas jets

该文研究水下超声速喷管燃气射流动力学特性。采用基于均质平衡流的mixture多相流模型和标准k？ε湍流模式,运用有限体积法和SIMPLE算法,求解了不同工况下的二维水下燃气射流的湍流流动。考虑了流体的可压缩性、黏性、重力作用、气水掺混效应和能量交换等复杂因素。通过对不同扩张比、不同水深和不同来流情况下喷管射流流场的数值计算结果的比较与分析,发现在环境背压较大的情况下,大扩张比喷管燃气射流会产生颈缩、断裂和回击现象;而小扩张比喷管和有来流情况下,喷管燃气射流形态较稳定。

Through comparing 30 years planned economy with 30 years market economy, the progress before reform and opening up and the enormous social and economic benefits since reform and opening up are described. It is considered that the gradual implementation of market economy is a necessary choice for reform and opening up. However, China＇s reform and opening-up has encountered new situations, new contradictions and new problems. Authors express the confidence to socialist markets economy.