Numerical investigation of rectangular thermal energy storage units with multiple phase change materials

In this study, heat transfer though a porous fin with rectangular cross section is investigated. The Darcy model is utilized to simulate heat transfer in this porous media. It is assumed that the fin is one-dimensional, homogenous, the flow is laminar, and the generated heat is a linear function of temperature. In this research, three different analytical methods are used to obtain the temperature distribution after deriving the heat transfer equation. In order to validate the obtained solution the collocation method (CM) is compared with the results by a numerical method, in order to validate the solutions, homotopy perturbation method (HPM) and homotopy analysis method (HAM) are employed. This problem is solved for the general case, and the output is obtained as a relationship for one iteration. The effects of various parameters including convection (Nc), porosity (Sh), Rayleigh number (Ra) are examined in this research.

Thermal analysis of porous fins enclosure with the comparison of analytical and numerical methods

Thermo-structural fatigue and lifetime analysis of a heat exchanger as a feedwater heater in power plant

In this study, heat transfer through a porous fin with the rectangular cross section that is subjected to laminar flow in an isotropic homogeneous medium is investigated. The Darcy model is used to...

Numerical Validation Heat Transfer of Rectangular Cross-Section Porous Fins

The purpose of this paper is to investigate the heat transfer of laminar and turbulent pulsating Al203/water nanofluid flow in a two-dimensional channel. In the laminar flow range, with increasing Reynolds number (Re), the velocity gradient is increased. Also, the Nusselt number (Nu) is increased, which causes increase in the overall heat transfer rate. Additionally, in the change of flow regime from laminar to turbulent, average thermal flux and pulsation range are increased. Also, the effect of different percentage of Al2O3/water nanofluid is investigated. The results show that the addition of nanofluids improve thermal performance in channel, but the using of nanofluid causes a pressure drop in the channel.,The pulsatile flow and heat transfer in a two-dimensional channel were investigated.,The numerical results show that the Al2O3/Water nanofluid has a significant effect on the thermal properties of the different flows (laminar and turbulent) and the average thermal flux and pulsation ranges are increased in the change of flow regime from laminar to turbulent. Also, the addition of nanofluid improves thermal performance in channels.,The originality of this work lies in proposing a numerical analysis of heat transfer of pulsating Al2O3/Water nanofluid flow -with different percentages- in the two-dimensional channel while the flow regime change from laminar to turbulent.

Numerical investigation of heat transfer of laminar and turbulent pulsating Al2O3/water nanofluid flow

Thermal analysis of moving porous fin wetted by hybrid nanofluid with trapezoidal, concave parabolic and convex cross sections

In this paper, the flow of non-Newtonian blood fluid with nanoparticles inside a vessel with a porous wall in presence of a magnetic field have been investigated. This study aimed to investigate various parameters such as magnetic field and porosity on velocity, temperature, and concentration profiles. In this research, three different models (Vogel, Reynolds and Constant) for viscosity have been used as an innovation. The governing equations are solved by Akbari-Ganji's Method (AGM) analytical method and the Finite Element Method (FEM) is used to better represent the phenomena in the vessel. The results show that increasing the Gr number, porosity and negative pressure increase the blood velocity and increasing the magnetic field intensity decrease the blood velocity.

Hydrothermal analysis on non-Newtonian nanofluid flow of blood through porous vessels

This article investigates the effects of geometric parameters on a turbulent asymmetrical heat transfer in vertical channels with radiation and blowing from a wall. Hydrodynamic behaviour and heat transfer results are obtained by the solution of the complete Navier–Stokes and energy equations using a control volume finite element method. In this paper, commercial codes were used to solve the equations. The equations involved were numerically solved with three turbulent models including Spalart-Allmaras, R-N-G k-e with ‘standard wall function’ wall nearby model, R-N-G k-e with ‘enhanced wall treatment’ wall nearby model and ‘ray tracing’ radiation techniques. Turbulent flow with ‘low Reynolds Spalart-Allmaras turbulence model’ and radiation with ‘discrete transfer radiation method’ was modelled. The results were compared with experimental data and appropriate methods were selected for turbulent modelling. The problems of different Grashof number, Reynolds number, radiation parameters and Prandtl number were solved and the effects of geometric parameters on the fluid flow, radiation-convection-blowing heat transfer and the total efficiency were determined.Copyright © 2015 by ASME

Numerical Simulation for Thermal Design of a Gas Water Heater With Turbulent Combined Convection

Analytical solution of the axisymmetric two-dimensional non-Fourier temperature field within a hollow sphere is investigated considering Cattaneo-Vernotte constitutive equation with general time-dependent heat flux. The material is assumed to be homogeneous and isotropic with temperature-independent thermal properties. The method of solution is the standard separation of variables method. Duhamel integral is used for applying the time-dependent boundary conditions. The presented solution is applied to special case of harmonic heat flux on outer surface.

Solution of Non-Fourier Temperature Field in a Hollow Sphere under Harmonic Boundary Condition

A numerical investigation was conducted to analyze the flow field and heat transfer characteristics in a vertical channel with radiation and blowing from the wall. Hydrodynamic behaviour and heat transfer results are obtained by the solution of the complete Navier–Stokes and energy equations using a control volume finite element method. Turbulent flow with "Low Reynolds Spalart-Allmaras Turbulence Model" and radiation with "Discrete Transfer Radiation Method" had been modeled. In order to have a complete survey, this article has a wide range of study in different domains including velocity profiles at different locations, turbulent viscosity, shear stress, suctioned mass flow rate in different magnitude of the input Rayleigh number, blowing Reynolds number, radiation parameter, Prandtl number, the ratio of length to width and also ratio of opening thickness to width of the channel. In addition, effects of variation in any of the above non-dimensional numbers on parameters of the flow are clearly illustrated. At the end resultants had been compared with experimental data which demonstrated that in the present study, results have a great accuracy, relative errors are very small and the curve portraits are in a great agreement with real experiments.

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Siamak Hosseinzadeh

Papers

Thermal analysis of moving porous fin wetted by hybrid nanofluid with trapezoidal, concave parabolic and convex cross sections

Hydrothermal analysis on non-Newtonian nanofluid flow of blood through porous vessels

Numerical Simulation for Thermal Design of a Gas Water Heater With Turbulent Combined Convection

Solution of Non-Fourier Temperature Field in a Hollow Sphere under Harmonic Boundary Condition

Two-dimensional numerical simulation of the combined heat transfer in channel flow