Thermal Engineering: Principles, Evolution, and Comparative Analysis with Classical Approaches

Abstract

Thermal engineering is the study of heat transfer, thermodynamics and energy conversion systems. However, through the years it has progressed from classical theories, which relied on empirical correlations, to enhanced computed and nanotechnology based approaches. This paper highlights the principles of thermal engineering, its important systems and latest developments of thermal engineering and provides extensive comparisons between the classical (traditional) methods and the most recent developments or innovations such as nanofluids, optimised heat transfer system etc. The study identifies areas of improvements, presents the shortcomings of previous models, and suggests areas for future study. The basic concepts of thermodynamic systems, such as closed system, open system and isolated system, system properties, equilibrium, thermodynamic processes and cycles, are also discussed. The Rankine cycle, heat exchanger and refrigeration cycles are some other classical thermal systems are also important applications of Traditional thermal systems Principles. The drawbacks of the classical approaches, e.g. low fidelity of the phenomena, assumed constancy of material properties, and overlook of micro scale phenomena, are discussed. Recent innovations in computational fluid dynamics (CFD), finite element analysis (FEA), microchannel heat sinks, improved convection and phase change materials are also covered. A special focus on nanofluids and hybrid nanofluid application is due to their potential in increasing the thermal conductivity and the heat transfer performance as compared to the conventional working fluids. A comparative study of classical and modern methods shows that the advanced methods have several benefits, such as higher accuracy of the models, more efficient use of heat and the possibility of connecting them to micro and nano scales. But the issues lie with nanofluid stability, high viscosity of nanofluid, pressure drop, high computational cost, and differences in experimental results. Finally, the paper outlines future prospects in the direction of optimal thermal system design with the aid of artificial intelligence, the development of smart heat exchangers, the implementation of sustainable refrigerants and integration with renewable energies. In conclusion, the advancements in thermal engineering underscore the need to blend the timeless wisdom of classical principles with contemporary innovations in computational tools and materials to create efficient and sustainable thermal solutions.