Comparative Investigation of the Thermal Conductivity of Water-Based Nanofluids with and without the Combination of Alumina and Carbon Nanotubes

Abstract

In the present study, the thermal conductivity of two distinct water-based nanofluids of single-walled CNTs and Al2O3, as well as their hybrid solution, was investigated experimentally. The Al2O3 and CNTs nanoparticle concentrations are taken to be 2%v/v, while the hybrid solution contained 2%v/v of both Al2O3 and CNTs nanoparticles. A PSS (Polly styrene sulphonic acid) solution was used as a surfactant to increase the suspension time of the nanoparticles to avoid sedimentation. The dispersion and breaking of the particles of CNT and Al2O3 into nano size were performed employing a probe sonicator and bath sonicator. Moreover, a hot plate magnetic stirrer was used to obtain a consistent liquid mixture. The experiments are performed on the Computer Controlled Thermal Conductivity of Liquid and Gases (TCLGC) unit available in the heat transfer lab at GIKI. The results concluded that the thermal conductivity of water-based single-walled CNT nanofluids was higher compared to Al2O3 and their hybrid solution. Therefore, Al2O3 and a hybrid solution are less desirable for thermal conduction compared to CNTs.

Keywords

• thermal conductivity
• CNTs
• Al₂O₃
• hybrid solution
• nanofluids