Comparative Theoretical and Experimental Studies of Breakup, Outgassing and Stress-Induced Cavitation of Newtonian and Polymerically Thickened Liquids

摘要CTS-0076648D。D·约瑟夫，明尼苏达大学建议研究液体在承受气流诱导应力或空化相关蒸汽态时的破碎过程。这些影响预计与高韦伯数或极低密度条件有关。对液体破碎机理的其他几个因素将进行研究，如形态、相对分子质量和粘弹性性质。特别是，激波管研究中已经被识别为瑞利-泰勒的不稳定性，现在将从开尔文·赫姆霍兹的观点来考虑，例如剥离液滴的侧面，从液滴中拉出的细丝的毛细不稳定，空化和放气。这部分研究的重点是解释高速电影和静态照片验证的最终液滴分布。此外，聚合物增稠液体在低压条件下的破碎已被证明非常依赖于增稠剂的浓度。建议研究这种工艺对聚合物类型、浓度和其他相关性质的依赖性。

AbstractCTS-0076648D. D. Joseph, University of MinnesotaIt is proposed to investigate the process of liquid fragmentation when submitted to gas flow induced stresses or to cavitation related vapor states. These effects are expected to be associated to high Weber number or very low-density conditions. Several additional contributing factors to the liquid breakup mechanism will be investigated, such as morphology, molecular weights and viscoelastic properties. In particular, the instabilities already identified as Rayleigh-Taylor in shock tube studies, will be now be considered from the Kelvin Helmhoz viewpoint, for such phenomena as stripping the side of the drop, the capillary instability of a filament pulled out of the drop, cavitation and outgassing. The focus of this part of the research is to explain the eventual droplet distribution as validated by high-speed movies and still photographs. Also, the breakup of polymer-thickened liquids under low-pressure conditions has been shown to be very dependent on thickener concentration. It is proposed to examined the dependence of such a process on polymer type, concentration and other related properties.