Comparative experimental analysis of fluid flow in a concentric tube exchanger having semi hollow cylindrical macro inserts with nanofluid and base fluid

Nanofluids represent a novel category of advanced heat transfer fluids composed of nanoparticles within a size range of 1-20 nm dispersed in a base fluid such as water. Contemporary research predominantly focuses on incorporating nanoparticles like Al2O3 and ZnO into the water at a 0.1% volume fraction to create nanofluids. Recent investigations aim to optimize thermal performance by introducing nanoparticles into the base fluids and inducing turbulence through various macro-inserts. Key factors influencing heat exchanger efficiency enhancement include geometric parameters, thermal conductivity and volume fraction. This study endeavours to analyse the thermal and fluid flow characteristics of a proposed nanofluid, augmenting thermal transfer through computational simulations and experimental validation, achieving an error margin of 3%-5%. The impact of rectangular micro inserts, with dimensions of 4 cm in height and longitudinal spacings of 5 cm and 11.5 cm, on the heat transfer rate is examined to enhance fluid flow turbulence. Results indicate that among different geometric profiles, the insert with a spacing of 11.5 cm demonstrates superior performance, yielding higher heat transfer rates and Nusselt numbers. This research holds significant implications for various industries including thermal, power, aviation, space and automotive sectors, particularly in the utilization of concentric tube heat exchangers across diverse applications. By exploring novel geometrical and fluid domains within heat exchangers, this study unveils promising avenues for enhancing the heat transfer efficiency compared to conventional methods, highlighting the potential for further investigation into alternative materials and configurations for heat elimination enhancement.

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[1] This research project is supported by Kumar Infratrade Pvt. Ltd. and infrastructure is provided by Shivalik College of Engineering, Dehradun.

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[2] Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025).