Enhancing heat transfer performance of automotive radiator with H2O / activated carbon nanofluids

Abstract

The deionized (DI) water and activated carbon (AC) nanofluids were produced at different volume concentrations (VCs) such as 0.1, 0.25, and 0.4 %. ACNMs were produced through the pyrolysis process of deadly available Kigelia Africana leaves in a muffle oven at 500 °C. The structural properties of the activated carbon nanomaterials (ACNMs) were described through the usage of SEM, EDS, XRD, and FTIR analyzers. Thermal exchange properties that as density (ρ), thermal conductivity (TC), specific heat (SH), and viscosity (µ) of DI water - AC-based nanofluids were evaluated experimentally. The five various mass flow rates (MFRs) namely 20, 40, 60, 80, and 100 g/sec were applied with different VCs of DI water - AC nanofluids in this study. In addition, the hot fluid (nanofluid) inlet temperature was constantly maintained with the help of a hot DI water bath at 50, 60, and 70 °C, respectively. The highest thermal conductivity (TC) augmentation attains up to 9.134 % is detected at 0.4 vol% of ACNMs loading at 70 °C. The addition of ACNMs augments the specific heat (SH) of the nanofluids substantially, and this augmentation diminutions with an increase in the ACNMs concentration. The addition of ACNMs in the DI water augments the Nusselt number by 21.76 %, 24.71 %, and 32.47 % for 50, 60, and 70 °C respectively, at a VCs of 0.4 % and mass flow rate of 0.1 kg/sec in the car radiator. In addition, turn up a palpable reduction in Reynolds number for specified MFRs for all the ACNM nanofluids.