Natural Convection from Heated Surface-Mounted Circular Cylinder H. Malah, Y. S. Chumakov, and S. Ramzani Movafagh 1 Introduction In recent years, there are more efforts on natural convection heat transfer from a hori- zontal cylinder, because of its practical applications. However, unconfined cylinder is well studied; the effect of introducing end-walls on the heat transfer rate of cylinder is considerably less investigated [1]. By development of computers and enhancement of advanced computational techniques, many studies of flow over a bluff body relevant to solid wall have been performed numerically [2], although experimental studies keep their place among researchers’ efforts because of their advantages [3]. All numerical and experimental studies confirmed the expected arise on the heat transfer rate in the upstream region of the cylinder. However, the flow configuration, bluff body geometry and applied conditions on solid walls affect the arising flow [4, 5]. In this study, a numerical model of a heated horizontal circular cylinder mounted on vertical isothermal plate is employed to evaluate the natural convection heat transfer. To quantify the effect of vertical plate on the heat transfer from the cylinder surface, the aspect ratio of the cylinder (H /D) is selected equal to 0.6, in order to immerse in the arisen boundary layer on the vertical plate entirely. This geometrical configuration is evaluated on the vertical plate at fixed Grashof number equals 3 × 10 8 that represents laminar Grashof number. As a result, we describe the three-dimensional characteris- tics of natural convection heat transfer, which affect flow around the circular cylinder mounted on vertical heated plate. The results proved the significant effect of height of cylinder on the heat transfer rate from circular cylinder surface in the case of H. Malah (B ) · Y. S. Chumakov Institute of Applied Mathematics and Mechanics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg 195251, Russian Federation e-mail: hamid.malah@gmail.com S. Ramzani Movafagh Department of Environmental Engineering, Faculty of Engineering and Technology, Saint-Petersburg State Institute of Technology, St. Petersburg 190013, Russian Federation © Springer Nature Singapore Pte Ltd. 2021 C. Wen and Y. Yan (eds.), Advances in Heat Transfer and Thermal Engineering , https://doi.org/10.1007/978-981-33-4765-6_1 3