Method comparison and measurement accuracy of thermal conductivity for several nanofluids

Nanofluid is a promising candidate to become the working fluid of pulsating heat pipes, the physical properties should be known before application. Several methods of measuring thermal conductivity of liquid are compared, especially for the single and double transient hot-wire methods. The obtained thermal conductivities by single Φ50μm and Φ20μm wire are close to those by double Φ50μm wire. The suspension characteristics of nanofluids are visualized. The evenly suspending state could be achieved in TiO₂/H₂O nanofluid by ultrasonic and pH value adjustment, however it is less effective for CuO/H₂O nanofluids. Also, the measurement setup is established and the thermal conductivities of four kinds of nanofluids are measured. The results show that the thermal conductivity will increase remarkably with the particle ratio for good suspension nanofluids TiO₂/H₂O. The measurement error could be less 3%.