摘要: |
含有剪切增稠液的振动控制装置在服役阶段涉及挤压过程,研究剪切增稠液的挤压力学性能有着重要的意义。采用石墨烯增强纯二氧化硅纳米颗粒剪切增稠液,并利用旋转流变仪开展了挤压流动实验,测试了不同剪切增稠液的流变性能和挤压流动力学性能,得到了黏度曲线以及不同挤压速度下法向应力和临界间隙的变化规律,分析了石墨烯对剪切增稠液流变性能和挤压流动力学性能的影响。结果表明,石墨烯增强的剪切增稠液的剪切增稠效应得到明显提高,其剪切增稠阶段的黏度峰值为599.42 Pa·s,与纯剪切增稠液相比提高了74%;同时在不同挤压工况下,随着石墨烯体积分数的增大,剪切增稠液的法向应力和临界间隙增大,其承载能力得到显著提高。在此基础上,基于流体润滑理论,讨论了石墨烯对剪切增稠液挤压流动力学性能的影响机理,将法向应力和临界间隙的增大归因于石墨烯能有效地阻碍纳米颗粒的滑动以及石墨烯与石墨烯之间、石墨烯与颗粒之间所存在的流体润滑力。本文的工作为设计挤压模式下的高性能剪切增稠液装置提供参考。 |
关键词: 剪切增稠液 流变性能 挤压流 黏度 石墨烯 |
DOI:10.11951/j.issn.1005-0299.20200050 |
分类号:TB381 |
文献标识码:A |
基金项目:国家自然科学基金资助项目(11672214). |
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Study on the influence of graphene on the squeeze flow mechanical properties of shear thickening fluid |
ZHOU Hao1,TAN Zhuhua2 [HJ0.98mm]
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(1. School of Science, Wuhan University of Technology, Wuhan 430070, China; 2. School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China)
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Abstract: |
Vibration control devices containing shear thickening fluids (STFs) are involved in squeezing processes during service period. Therefore, the study on squeeze mechanical properties of STFs is of great significances. Graphene were adopted to reinforce the pure SiO2 nanoparticle-based STF. The squeeze flow experiment was conducted by a rotary rheometer. The rheological properties and squeeze flow mechanical properties of different STFs were tested. The correlation between normal stress and critical gap under different squeeze speeds as well as the viscosity curve was obtained. The effects of graphene on the rheological properties and squeeze flow mechanical properties of STF were analyzed. The results showed that the graphene reinforced STF showed a significant increase in both viscosity and shear thickening efficiency. At the shear thickening stage, the maximum viscosity of the reinforced STF was 599.42 Pa·s, 74% higher than that of the pure STF. At the same time, under different squeeze conditions, with increasing the graphene volume fraction, both the normal stress and critical gap of STF increased, and the bearing capacity of STF was enhanced. Moreover, based on the hydrodynamic lubrication theory, the mechanism on how graphene affects the squeeze flow mechanical properties of STF was also discussed in this paper. It is concluded that the increase in the normal stress and critical gap can be attributed to the fact that graphene can effectively prevent the flow of nanoparticles and the existence of fluid lubrication force between graphene and graphene, graphene and particles. The results obtained in this paper can shed more insights into the design of high-performance STF devices under squeezing mode. |
Key words: shear thickening fluid rheological property squeeze flow viscosity graphene |