I. Behunek

Properties and Numerical Modeling-Simulation of Phase Changes Material

There exists a domain of models that is principially classified into the linear and non-linear fields of modelling. In the field of non-linear modelling, significant progress has been made since the 1960s thanks to the widespread and regularly available computer technology. This dynamic development influenced a large number of problems including the description of physical behaviour of non-trivial tasks. Non-linear models are solved in the material, spatial, and time domains. However, certain non-linear model domains are not sufficiently developed or regularly used for analysis of the more simple tasks. This group includes task models using non-linear discontinuous characteristics of materials, which can be exemplified by the change of state of a material during heating or cooling. In this section, we would like to use several descriptive examples to expose the problem of thermal tasks solution utilizing applied materials with a phase change (PCM) (Gille, T.; at al. 2007, Volle, F. at al. 2010, Shi, L.P.; at al. 2006). These are mostly coupled tasks (Fiala,P. December 1998). Within the specification of different aspects of the solution process, emphasis will be placed on the final accuracy of the results of numerical analyses, and therefore (rather than focusing on a complete description of the model) the text will accentuate problematic spots within the solution of such tasks. The PCM characteristics are demonstrated on the task of designing a low-temperature accumulator, an efficient cooler of electronic components, and a separator of impurities in an industrial oil emulsion.

Numerical Model of Optimization Lead-Acid Accumulator Grids

This article deals with chemical processes during charging and discharging of the lead-acid accumulator. There are presented one shape of electrode grids in this work but we researched more variants. We prepared numerical models based on combined finite element method (FEM) and finite volume method (FVM) of those variants and computed current density distribution on the surface of electrodes. The model joins magnetic, electric and current field, flow field and chemical nonlinear ion model. Results were obtained by means of FEM/FVM as a main application in ANSYS software.

Numerical Model of Inductive Flowmeter

This article deals with physical and chemical processes during measurement with an inductive ∞owmeter. A theoretical model and an example of numerical solution are presented here. We prepared numerical models based on the combined flnite element method (FEM) and the flnite volume method (FVM) of one of the three variants and computed the output voltage of the ∞owmeter electrodes. The model joins the magnetic, the electric and the current flelds, the ∞ow fleld and a chemical nonlinear ion model. The results were obtained by means of the FEM/FVM as a main application in ANSYS software.

Properties and Numerical Simulation of CaCl2.6H2O Phase Change

This paper deals with the application of phase change materials (PCM) for thermal management of integrated circuits as a viable alternative to active forced convection cooling sys- tems. The paper presents an analytical description of melting and freezing process, an analytical solution of CaCl2.6H2O phase change in 1D and the results of a numerical model of phase change. The numerical model joins thermal fleld, air ∞ow with respects to material phase change. This numerical model was obtained by means combined of the flnite element method (FEM) and flnite volume method (FVM) applied as main method in ANSYS software.

Numerical Model of Optimization of the Lead-acid Accumulator Grids

This article deals with chemical processes during charging and discharging of the lead-acid accumulator. There is presented one shape of electrode grids in this work, but we researched more variants. We prepared numerical models based on the combined flnite element method (FEM) and flnite volume method (FVM) of those variants and computed current density distribution on the surface of electrodes. The model joins magnetic, electric and current flelds, ∞ow fleld and chemical nonlinear ion model. Results were obtained by means of the FEM/FVM as a main application in ANSYS software.

Turbulence Modeling of Air Flow in the Heat Accumulator Layer

The article deals with one layer of a heat accumulator which is suitable for solar systems. Here is presented numerical coupled model with turbulent ∞ow thermal fleld depends on time. There is a numerical model of the air turbulence, heat transfer, conduction and also phase change of CaCl2.6H2O which is used to increase the density of stored energy. The numerical solution was done by the help of flnite element method (FEM) in ANSYS software. DOI: 10.2529/PIERS060901083329