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The entropic lattice Boltzmann (LB) method has recently been extended to include energy conservation in order to simulate weakly compressible flows. One of the limitations of this method when using the BGK collision model is the fixed Prandtl number. In this paper a new simple method is proposed and validated in order to simulate fluids of arbitrary Prandtl number.

An improved lattice Boltzmann model is proposed for thermal flows in which the viscous heat dissipation and compression work by the pressure can be neglected. In the improved model, the whole complicated gradient term in the internal energy density distribution function model is correctly discarded by modifying the velocity moments' condition. The corresponding macroscopic energy equation is exactly derived through Chapman–Enskog expansion. In particular, based on the improved thermal model, a double-distribution-function lattice BGK model is developed for two-dimensional Boussinesq flow, which is a typical flow with negligible viscous heat dissipation and compression work. A two-dimensional plane flow and the natural convection of air in a square cavity with various Rayleigh numbers are simulated by using the double-distribution-function lattice BGK model. It is found that there is excellent agreement between the present results with the analytical or benchmark solutions.

The Average Phase Space Density (APSD) of very high energy nuclear collisions at the total "freeze-out" temperature offers an indirect but convenient tool to assess the merit and worth of the pionisation models. We have attempted to apply here a specific multiple production model with a view to estimating the APSD of pions for a set of sulphur-induced ultrarelativistic heavy-ion collisions in a unified manner, to compare them finally with the experiment-based results of NA35 and NA44-groups at CERN and also with the calculational results based on the thermal model. The specific implications of the present approach have also been pointed out in the end.

Midrapidity results on multiplicity density $dN∕dy$ and transverse momentum distributions $E\frac{d^{3}N}{d^{3}p}$ of pions, kaons and protons in Au + Au collisions at $\sqrt{s_{NN}}=9.2\mathrm{\text{GeV}}$ are reproduced by using our earlier proposed Unified Statistical Thermal Freeze-out Model (USTFM). The calculated results are found to be in fairly good agreement with the experimental data points taken from STAR experiment. Freeze-out conditions in terms of a transverse flow velocity parameter and the thermal freeze-out temperature are extracted from the fits of transverse momentum spectra of the particles at different collision centralities. A large value of midrapidity chemical potential reveals the effects of almost complete stopping in the center-of-mass frame of the system produced. The resonance decay contributions are found to have a negligible effect on the transverse momentum spectra of the particles while these are found to be significant for determining the shape of the rapidity spectra.

We present an improved dynamical thermal model and the corresponding experimental efforts to determine thermal profiles of thin metallic films deposited on thick substrates (bimaterial system) as are usually used in microelectronics. A dynamical thermal model to characterize the Joule heating of a metallic film/substrate system, as a function of the applied energy and the thickness is discussed. Good agreement between theoretical and measured thermal profiles on different bimaterial systems support the theoretical model obtained by solving a harmonic oscillator equation. By combining the thermal model and the experimental results it is possible to determine the convective coefficient of the room conditions, the diffusive time constant, and to quantify the different mechanisms of heat loss as a function of the physical properties and the geometrical parameters. The improved thermal model can be useful to rapidly predict a thermal behavior of film/substrate systems that are used for microelectronics.

The temperature field due to laser-induced discharge surface strengthening (LIDSS) has significant influence on the microstructure transformation and also the formation quality of discharge pit. A transient axisymmetric thermal model is developed to estimate the temperature distribution during LIDSS based on Fourier heat conduction equation. In the model, a Gaussian heat input distribution is assumed; temperature-dependent material properties are applied and the latent heat of fusion and vaporization is calculated on an enthalpy method. As an application, we use this model to compute the temperature field during the process of tungsten tool electrode machining 1045 steel workpiece and find that the computational results are well consistent with the experimental data.

In this paper, a theoretical model of an electrochemical battery connected with three diode model of a photovoltaic module is presented. To calculate selected parameters of the electrochemical battery model an iteration-approximation method has been employed. Then there are presented chosen curves of LiFePO4 batteries obtained from the experimental research and simulation of the thermal-electrochemical model well known as a combined model. Moreover, by using a combined model, the heat generation of the battery has been calculated. The model was prepared to analyze the influence of selected thermodynamic and electrochemical parameters including the shunt resistance value, series resistance value, solar radiation power density on the photovoltaic module power value for winter and summer season. As a result of the performed simulations with photovoltaic (PV) module and without PV module in the specific daily cycle, the curves of battery state of charge (SOC) have been shown. The presented results inform about the dynamic operation of the simulated LiFePO4 batteries which are integrated with PV module in hybrid micro-installation.