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提出了在相变悬浮液中添加TiO2纳米颗粒以提高其热导率的概念,并使用旋转流变仪和热物性仪测量了这种新型悬浮液流变特性和热导率。研究结果表明,对于体积浓度为10%的相变悬浮液,当加入的纳米颗粒质量浓度不超过5%(体积浓度1.18%)时,低剪切率下悬浮液表现出非牛顿流体的特性,高剪切率下仍可视为牛顿流体。相变悬浮液的黏性随纳米颗粒浓度增加而增加,当纳米颗粒质量浓度为5%时,相变悬浮液的黏性提高约23%。相变悬浮液的热导率随着纳米颗粒浓度的增加而增加,当纳米颗粒质量浓度为5%时,相变悬浮液热导率提高约7.3%。
The concept of adding TiO2 nanoparticles to the phase change suspension to improve its thermal conductivity was proposed. The rheological properties and thermal conductivity of the new suspension were measured by using a rotating rheometer and a thermophysical analyzer. The results show that the suspensions show the characteristics of non-Newtonian fluid at low shear rate when the mass concentration of nanoparticles added is not more than 5% (volume concentration 1.18%), High shear rate can still be regarded as Newtonian fluid. The viscosities of the phase-change suspension increase with the increase of nanoparticle concentration. When the concentration of nanoparticles is 5%, the viscosity of the phase-change suspension increases by about 23%. The thermal conductivity of phase change suspension increases with the concentration of nanoparticles, and the thermal conductivity of phase change suspension increases by about 7.3% when the concentration of nanoparticles is 5%.