Impact of nanoparticles loading to a novel hybrid TiO₂-CNTs/water nanofluid on thermal performance enhancement

Abstract

This present work investigated the thermal characteristics and hydrodynamics behavior of TiO₂-CNTs/water hybrid nanofluids for laminar and turbulent conditions. Assuming hybrid nanofluids as Newtonian fluids, simulation-based evaluation was conducted using a single-phase approach. Various nanoparticles loading and Reynolds number were employed to characterize the observed hybrid nanofluids’ convective heat transfer coefficient and friction factor. The ratio between heat transfer performance and pressure drop enhancement was analyzed to understand thermal performance. Constant heat flux of 6500 W/m² and low nanoparticle concentration from 0.10 to 0.20 vol.% were applied in this simulation. The results revealed that adding CNTs nanoparticles did not significantly affect friction factor enhancement at very low concentrations due to their good tribological properties. For the thermohydraulic characteristics, the observed hybrid nanofluids were better than those of water. The thermal performance factor magnitudes of hybrid nanofluids were above 1.0 even though they did not have significant magnitudes at very low concentrations, 1.01 and 1.07 for laminar and turbulent flow, respectively.

Keywords:

• Carbon nanotubes
• hybrid nanofluids
• simulation evaluation
• thermal performance factor
• titania

Additional information

Funding

This work was supported by LPPM (Lembaga Penelitian dan Pengabdian kepada Masyarakat) of Universitas Sebelas Maret, Surakarta, Indonesia in Fundamental Research scheme (PF-UNS) under Grant Number: 254/UN27.22/PT.01.03/2022.