Copyright © 2026 Authors retain the copyright of this article. This article is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

@article{204841,
        author = {M.Santhi Kumari and M.S.Rao},
        title = {Experimental and Numerical Investigation of Natural Convective Heat Transfer on Nano-Coated Flat Plate and Effects of Material Selection and Geometric Orientation},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {13},
        number = {1},
        pages = {4959-4973},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=204841},
        abstract = {Natural convection heat transfer enhancement has become an important area of research in thermal engineering applications such as electronic cooling, solar thermal systems, heat exchangers, and thermal management devices. Nano-coating technology improves heat transfer characteristics due to enhanced thermal conductivity, increased surface roughness, and improved surface wettability. This study presents an experimental and numerical investigation of natural convective heat transfer over nano-coated flat plates with different substrate materials and geometric orientations. Stainless steel, aluminium, and copper plates of dimensions 600 × 50 × 6 mm were tested under steady-state natural convection conditions using a constant heat input of 50 W. The plate inclination angle was varied from 0° to 90° to evaluate the influence of geometric orientation on thermal performance. Surface temperatures were measured using calibrated K-type thermocouples, and the corresponding thermal parameters such as film temperature, Grashof number, Nusselt number, and convective heat transfer coefficient were determined. Numerical simulations were carried out using ANSYS Fluent with the Boussinesq approximation to model buoyancy-driven airflow and thermal boundary layer development around the heated plate. The results showed that increasing the inclination angle enhanced natural convection heat transfer due to stronger buoyancy effects and improved thermal plume formation. Among the tested materials, stainless steel exhibited the highest Nusselt number, while copper showed lower surface temperatures because of its superior thermal conductivity. Nano-coatings significantly improved thermal performance, with Nano-Graphene providing the maximum enhancement of approximately 25–26% in Nusselt number and heat transfer coefficient compared with bare surfaces. The numerical results showed good agreement with experimental observations, confirming the effectiveness of the CFD model in predicting natural convective heat transfer behaviour.},
        keywords = {},
        month = {June},
        }