Fixed Grid Numerical Models for Solidification and Melting of Phase Change Materials (PCMs)
| Autor: | Massimo Garai, José Henrique Nazzi Ehms, Rejane De Césaro Oliveski, Luiz Alberto Oliveira Rocha, Cesare Biserni |
|---|---|
| Přispěvatelé: | José Henrique Nazzi Ehm, Rejane De Césaro Oliveski, Luiz Alberto Oliveira Rocha, Cesare Biserni, Massimo Garai |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
melting and solidification processes
Materials science 020209 energy computational performance 02 engineering and technology Computational fluid dynamics lcsh:Technology lcsh:Chemistry Viscosity Latent heat phase change materials (pcms) 0202 electrical engineering electronic engineering information engineering General Materials Science Boundary value problem Instrumentation lcsh:QH301-705.5 Fluid Flow and Transfer Processes melting and solidification processe business.industry lcsh:T Process Chemistry and Technology General Engineering Mechanics 021001 nanoscience & nanotechnology Grid Solar energy lcsh:QC1-999 Computer Science Applications lcsh:Biology (General) lcsh:QD1-999 lcsh:TA1-2040 computational fluid dynamics (cfd) 0210 nano-technology business lcsh:Engineering (General). Civil engineering (General) Thermal energy lcsh:Physics Efficient energy use |
| Zdroj: | Applied Sciences, Vol 9, Iss 20, p 4334 (2019) |
| ISSN: | 2076-3417 |
| Popis: | Phase change materials (PCMs) are classified according to their phase change process, temperature, and composition. The utilization of PCMs lies mainly in the field of solar energy and building applications as well as in industrial processes. The main advantage of such materials is the use of latent heat, which allows the storage of a large amount of thermal energy with small temperature variation, improving the energy efficiency of the system. The study of PCMs using computational fluid dynamics (CFD) is widespread and has been documented in several papers, following the tendency that CFD nowadays tends to become increasingly widespread. Numerical studies of solidification and melting processes use a combination of formulations to describe the physical phenomena related to such processes, these being mainly the latent heat and the velocity transition between the liquid and the solid phases. The methods used to describe the latent heat are divided into three main groups: source term methods (E-STM), enthalpy methods (E-EM), and temperature-transforming models (E-TTM). The description of the velocity transition is, in turn, divided into three main groups: switch-off methods (SOM), source term methods (STM), and variable viscosity methods (VVM). Since a full numerical model uses a combination of at least one of the methods for each phenomenon, several combinations are possible. The main objective of the present paper was to review the numerical approaches used to describe solidification and melting processes in fixed grid models. In the first part of the present review, we focus on the PCM classification and applications, as well as analyze the main features of solidification and melting processes in different container shapes and boundary conditions. Regarding numerical models adopted in phase-change processes, the review is focused on the fixed grid methods used to describe both latent heat and velocity transition between the phases. Additionally, we discuss the most common simplifications and boundary conditions used when studying solidification and melting processes, as well as the impact of such simplifications on computational cost. Afterwards, we compare the combinations of formulations used in numerical studies of solidification and melting processes, concluding that “enthalpy−porosity” is the most widespread numerical model used in PCM studies. Moreover, several combinations of formulations are barely explored. Regarding the simulation performance, we also show a new basic method that can be employed to evaluate the computing performance in transient numerical simulations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|