Volume Fraction Effect on Heat Transfer Performance of an Oscillating Heat Pipe

摘要

It has been demonstrated that nanofluids can enhance the heat transfer performance of an oscillating heat pipe, which largely depends on the volume fraction of the nanofluid. The optimum volume fraction reported by investigators is very different, ranging from 100 ppm to 1%. In the current investigation, the effect of the volume fraction of nanoparticles on the heat transfer performance of oscillating heat pipes was investigated experimentally. Water was used as the base fluid for the oscillating heat pipe. Two types of alumina nanoparticles with sizes of 80 (cylinder-like) and 40 nm(brick-like), respectively, were used to study the volume fraction effect The experimental results demonstrate that the alumina particles added in the oscillating heat pipe affect the heat transfer performance depending on the volume fraction. Although the alumina nanofluid with a very low volume fraction of 1 ppm can enhance the oscillating heat pipe heat transfer performance, the alumina nanofluid with a high volume fraction may not enhance heat transfer. In addition, multi-optimum values of the volume fraction exist for the oscillating heat pipe investigated in this study.