纳米流体热导率试验

Experiments on thermal conductivity of nanofluids

采用自行设计的瞬态热线装置,测试了不同种类纳米流体的热导率,分析研究了粒子体积分数、粒径、温度、分散剂等因素对纳米流体热导率的影响.结果表明,低体积分数纳米流体的热导率比基液有较大幅度的提高,最大可达40%左右;纳米流体的热导率随着粒径的增大而减小,随着粒子体积分数的增大、温度的升高而增加,且分散效果越好的纳米流体热导率越大.试验热导率值大于常规固液混合物的H-C模型预测值,表明纳米流体具有不同于一般固液混合物的独特的优良导热特性.

Thermal conductivities of several nanofluids （NFs） were measured using transient hot-wire apparatus. Influences of volume fraction of particles, particle sizes, temperature and dispersants on thermal conductivities of nanofluids were analyzed. Experimental results showed that nanofluids have substantially greater thermal conductivities than those of base liquids, which increase by as large as about 40%, and that thermal conductivities of nanofluids decrease with the increase of particle dimension, while they increase with the increase of volume fraction of particles, temperature and suspension stability. Comparisons between experiments and the H-C model showed that the data of the former are generally larger than those of the latter, and that nanofluids have specific heat transfer behaviors compared with conventional solid-liquid mixtures.