二甲醚射流雾化的不稳定性研究

Research on Atomization Instability of Dimethyl Ether Jet

利用线形稳定性理论,推导出可用来描述粘性射流表面扰动发展所满足的色散方程,并进行了无量纲化处理,利用该色散方程对二甲醚射流在正常条件和闪急沸腾条件下的不稳定性进行了研究。结果表明,在正常喷射条件下,提高射流速度和减小液体粘度可促进二甲醚射流的雾化效果,而表面张力和环境气体密度对射流不稳定性的影响则相对复杂;在闪急沸腾喷射条件下,闪急沸腾效应越明显,二甲醚射流越不稳定。

Based on the theory of linear stability analysis, a dispersion equation which describes the relation between disturbance growth rate and its wave number was derived, and the dimensionless form and solution procedure of the dispersion equation were obtained. In order to improve the understanding of atomization mechanism of dimethyl ether （DME） jet, the instability of DME jet under normal and superheated conditions were analyzed. Some valuable conclusions are obtained as follows： under normal condition, increasing the relative velocity and decreasing the liquid viscosity are able to improve the atomization of DME jet, while the influence of surface tension and surrounding air density on the DME jet instability are relatively complicated; the effect of flashing boiling is capable of improving the instability of DME jet under superheated condition.