STUDY AND VALIDATION OF MESHES IN TURBULENT ISOTHERMAL PROBLEMS OF NATURAL CONVECTION IN FLAT PLATES

The study of natural convection on flat plates is of great interest in the areas of Engineering, both for the simplicity of geometry and the wide variety of applications. In the study and definition of a numerical model, an ideal mesh configuration is the one that best represents physically, with minimal numerical influence and with the lowest computational cost, the problem addressed. The influence of two mesh configurations (non-uniform staggered and entirely uniform), at different refinement levels, was studied to evaluate natural convection heat transfer rates in flat plates of AR = 5; in isothermal conditions, in turbulent regime with the κ−ω SST RANS model and using free and open-source software OpenFOAM®. The physical-numerical methodology applied, and the numerical results obtained were validated from experimental results in the literature. The non-uniform staggered mesh configuration proved to be more adequate in precision, and computational cost to the problem situation studied. The entirely uniform mesh proved to be infeasible due to the high number of elements and computational cost demanded

DIMENSIONLESS PHYSICAL-MATHEMATICAL MODELING OF TURBULENT NATURAL CONVECTION

Natural convection heat transfer is present in the most diverse applications of Thermal Engineering, such as in electronic equipment, transmission lines, cooling coils, biological systems, etc. The correct physical-mathematical modeling of this phenomenon is crucial in the applied understanding of its fundamentals and the design of thermal systems and related technologies. Dimensionless analyses can be applied in the study of flows to reduce geometric and experimental dependence and facilitate the modeling process and understanding of the main influence physical parameters; besides being used in creating models and prototypes. This work presents a methodology for dimensionless physical-mathematical modeling of natural convection turbulent flows over isothermal plates, located in an “infinite” open environment. A consolidated dimensionless physical-mathematical model was defined for the studied problem situation. The physical influence of the dimensionless numbers of Grashof, Prandtl, and Turbulent Prandtl was demonstrated. The use of the Theory of Dimensional Analysis and Similarity and its application as a tool and numerical device in the process of building and simplifying CFD simulations were discussed

Toward greener supply chains: is there a role for the new ISO 50001 approach to energy and carbon management?

© 2016, The Author(s). Considering the increased interest of stakeholders in climate change and a low-carbon economy, this article has investigated and identified several contributions of the ISO 50001 in support of the adoption of green supply chain management (GSCM). In this context, energy efficiency and reduced CO 2 emissions are critical. Therefore, the proposal for and the requirements of ISO 50001 can generate useful insights on how to structure green and low-carbon supply chains, hence helping to address the challenges posed by climate change

EXPERIMENTAL METHODOLOGY FOR THE STUDY OF NATURAL CONVECTION ON FLAT AND CORRUGATED PLATES

Natural convection is present in the most different Thermal Engineering systems, such as solar collectors, electric furnaces, electronic equipment cooling, lubrication, thermal comfort projects in buildings, etc. In the last decade, the number of research on natural convection heat transfer has increased considerably, especially in the areas of physical-numerical modeling and validation, experimental construction and efficiency optimization of thermal systems, and related technologies. This work presents an experimental methodology for studying natural convection on flat and corrugated plates. The design and construction stages of the experimental apparatus, data processing and analysis, physical-mathematical modeling and uncertainty analysis were extensively explored. The applications and extensions of the proposed methodology were discussed in the numerical-experimental validation of physical-numerical modeling methodologies, design and optimization of the experimental apparatus and also of measuring instruments and, finally, in sensitivity analysis studies to reduce the propagation of uncertainties. The limitations of the proposed methodology were discussed, pointing out suggestions for future work