Nucleate pool boiling thermal management systems of hydrazine reduced graphene oxide (H-rGO) nanofluids with rough surface

• Published in: Energy sources. Part A, Recovery, utilization, and environmental effects Recovery, utilization, and environmental effects, 2023-08, Vol.45 (3), p.6994-7007
• Main Authors: Rajaram, Kamatchi, Raman, Mohan, Dhanapal, Kalaimegam, Muthusamy, Suresh, Ramamoorthi, Ponarun, Govindasamy, Murugesan, Mishra, Om Prava
• Format: Article
• Language: English
• Subjects: contact angle; nucleate boiling; Reduced graphene oxide; thermal management; surface roughness
• ISSN: 1556-7036; 1556-7230
• DOI: 10.1080/15567036.2023.2217110

Nucleate pool boiling of hydrazine-reduced graphene oxide (H-rGO) with rough surface is experimentally investigated. Using the created nucleate boiling setup, heat transfer coefficient (HTC) of nanofluids is investigated with rough surface. As compared with base fluid, HTC of nanofluids increases with concentrations. At maximum heat flux, HTC of higher concentration with rough surface is found as ~29.44 kW/m 2 K. A detailed study on surface roughness, contact angle, and microscopic image of boiled surface is conducted. Surface roughness of nanofluid boiled heat surface decreases with increasing concentrations. Contact angle on boiled surfaces exhibits hydrophobic nature and increases with concentrations. Hence, it is difficult to interpret the HTC of nanofluids with a single parameter. It is suggested that HTC of nanofluids depends on modification of heating surface due to nanodeposits (formation of pores), which aid for the enhancement. In addition, a semi-analytical model is employed to determine the nucleation sites on the surface and it matches well with experimental results of HTC.