摘要
温度变化对纳米流体粘度的影响是很明显的。结果表明:含有表面活性剂的纳米流体的黏度在温度低于60℃时,黏度随温度的升高而降低,超过此温度后,纳米流体的黏度随温度的升高而升高。只含有纳米粒子的纳米流体黏度随温度的升高而降低,高温时黏度随温度升高而减小的幅度减小,而使用表面活性剂后黏度与温度的关系出现异常,高温时黏度随温度的增加而增加。随着温度的升高,纳米粒子的布朗运动加强,粒子的无序运动增加流体流动的阻力,虽然表面活性剂的使用提高了纳米流体的稳定性,但大分子结构的表面活性剂吸附在粒子周围,致使粒子作布朗运动时大大增加液体的粘性,以至高温时纳米流体黏度随温度的升高而升高。本研究还对Cu-water、ZrO2-water纳米流体的黏度与温度的关系式进行拟合,拟合公式与实验数据吻合,误差小于0.5%,拟合公式中纳米流体的黏度与温度、粒子体积分数和基液有关。
The temperature showed significant effect on the viscosity of nanofluids. The results found that the shear viscosity of nanofluids with surfactant decreased with the increasing of the temperature below a threshold of 60℃. While the viscosity of nanofluids increased with the increasing of the temperature above 60℃. The viscosity of the nanofluids without any surfactant decreased with the increasing of temperature, the tendency of deereasing became slow as the increasing of temperature. The Brownian movement was enhanced due to the increasing of the temperature,so the flow resistance was increased with unordered movement of the nanoparticles. But the viscosity of nanofluids increased with the increasing of temperature after the surfactant added. The surfactant not only improved the stability of nanofluids but also increased the viscosity of nanofliuds owing to its macromolecular structure. The relational expression was fitting between the viscosity of Cu-water and ZrO2-water nanofluids and the temperature. The expression was fitted well to the experimental data,and the error was not exceeded 5%. The temperature, volume fraction of nanoparticle and the base-fluid had the influence of nanofluid＇s viscosity in the expression.
出处
《化工新型材料》
CAS
CSCD
北大核心
2014年第8期79-81,共3页
New Chemical Materials
基金
国家自然科学基金(11102074)
江苏省自然科学基金面上项目(BK2011463)
关键词
纳米流体
黏度
温度
表面活性剂
nanofluid, viscosity, temperature, surfactant
