Numerical analysis of unsteady heat conduction in regular solid bodies comprising natural convection to nearby fluids

HEAT TRANSFER-ASIAN RESEARCH, vol.47, no.7, pp.887-906, 2018 (ESCI)

• Publication Type: Article / Article
• Volume: 47 Issue: 7
• Publication Date: 2018
• Doi Number: 10.1002/htj.21356
• Journal Name:
• Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
• Page Numbers: pp.887-906
• Keywords: finite difference method, horizontal cylinder, natural convection, numerical temperature distribution and numerical total heat transfer, sphere, unsteady unidirectional heat conduction, vertical plate, TURBULENT FREE-CONVECTION, CORRELATING EQUATIONS, LAMINAR
• Kocaeli University Affiliated: Yes

Abstract

The present paper addresses unsteady, unidirectional heat conduction in regular solid bodies (vertical plate, horizontal cylinder, and sphere) that exchange heat by natural convection with a neighboring fluid. From thermal physics, natural convection constitutes a worst-case scenario for forced convection cooling. Under the premises of natural convection heat transfer, the unsteady, 1-dimensional heat conduction equation consists in a linear parabolic partial differential equation with a dominant natural convection boundary condition represented by the mean convective coefficient that depends upon temperature. As expected, the nonlinear unsteady, unidirectional heat conduction problem is complex and does not admit an exact, analytical solution. Instead, the nonlinear unsteady, unidirectional heat conduction problem forcibly necessitates approximate numerical treatment with the finite difference method. The computed dimensionless center, surface, and mean temperatures varying with dimensionless time are obtained numerically and are graphed for 3 solids: iron, aluminum, copper exposed to 3 fluids: air, water, oil; the 6 media are used in numerous engineering applications.