Seyfolah Saedodin

Semnan University · Department of Mechanical Engineering

The thermal behavior of flooded lead-acid batteries with different distances between their electrodes, in which there takes place a temperature rise, was investigated at different rates of charging and discharging of these batteries with the use of the PIV method. It was established that, in the case of small rates of charging and discharging of su...

In this study, the rheological behavior and tribological properties of a nano-lubricant containing SiO2 nanoparticles in SAE40 engine oil are experimentally investigated. Nano-lubricant has been prepared with two-step method using an ultrasonic homogenizer. The rheological behavior of nano-lubricant checked out in all studied temperatures (ranging...

In the Flooded Lead_Acid Batteries (FLAB), gas bubbles are initially formed on the surface of the electrodes, which are produced by electrochemical reactions, and then released into the electrolyte. In the present investigation, the effect of surface characterization of electrodes of FLAB on the gas bubble dynamic parameters in the electrolyte flow...

One of the leading challenges for researchers is meeting the industry's need for fast charging-discharging and high capacity batteries, increasing the Charge-discharge rate (C-rate) always followed by high temperatures due to thermo-electrochemical reactions and a drastic reduction in the capacity of batteries. Flooded Lead_ Acid Batteries (FLAB) a...

Improving the flooded-electrolyte batteries performance in fast charging and discharging processes has attracted many researchers. Due to electrochemical reactions during charging and discharging process in these batteries, many insoluble gas bubbles are produced within the electrolyte. These bubbles have a major effect on the performance of the el...

This article investigates the thermal performance of convective-radiative annular fins with a step reduction in local cross section (SRC). The thermal conductivity of the fin’s material is assumed to be a linear function of temperature, and heat transfer coefficient is assumed to be a power-law function of surface temperature. Moreover, nonzero con...

In the present work the efficiency of a solar parabolic trough has been investigated experimentally. Parabolic trough solar collectors constitute a proven source of thermal energy for industrial process heat and power generation. The impact of using the partially porous media in the absorber on the efficiency of PTC (parabolic trough collector) has...

In the present work the efficiency of a solar parabolic trough has been investigated experimentally. Parabolic trough solar collectors constitute a proven source of thermal energy for industrial process heat and power generation. The impact of using the partially porous media in the absorber on the efficiency of PTC (parabolic trough collector) has...

Weld geometry is a critical factor for determining the quality of Ti6Al4V welded joints. The size of the weld cross section profile has been quantitatively investigated through experimental and numerical analysis. Due to the difficulties in temperature measuring of the molten pool region, the temperature distribution through numerical simulation wa...

In this study, the forced convective in a tube filled with porous media is investigated analytically based on the perturbation methods. Thermal conductivity of the medium is assumed to be a linear function of radius. The Brinkman–Forchheimer-extended Darcy and local thermal equilibrium models are applied for momentum and energy equations. Analytica...

The application of new methods to solution of non-Fourier heat transfer problems has always been one of the interesting topics among thermal science researchers. In this paper, the effect of laser, as a heat source, on a thin film was studied. The Dual Phase Lagging (DPL) non-Fourier heat conduction model was used for thermal analysis. The thermal...

An experimental research has been conducted on low concentration of silver-water nanofluids through a straight tube for turbulent flow condition. This study aims at showing the impact of nanoparticle existence and/or volume concentration on thermal conductivity, dynamic viscosity, convective heat transfer characteristics, and pressure drop in turbu...

The effect of laser, as a heat source, on a one-dimensional finite body was studied in this paper. The Cattaneo-Vernotte non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature-dependent which resulted in a non-linear equation. The obtained equations were solved using the approximate-analyti...

Heat transfer phenomenon within a one-dimensional finite fin subjected to the action of a constant heat source was studied in this paper. The Catt aneo-Vernott e non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature-dependent which resulted in a nonlinear equation. The obtained equations w...

In this paper, the non-Fourier heat conduction in a semi-infinite body was examined. The heat wave non-Fourier heat conduction model was used for thermal analysis. Thermal conductivity was assumed temperature-dependent which resulted in a non-linear equation. The heat source was also considered temperature-dependent which resulted in a non-homogene...

The conjugate heat transfer inside microchannels filled with porous media in the slip regime is analytically investigated based on the local thermal nonequilibrium model, i.e., assuming independent temperatures for the solid and fluid phases of the porous material. The internal heat generations within both the fluid and solid phases of the porous m...

The aim of this work was to investigate the effects of temperature and solid volume fraction on thermal conductivity of CNTs-Al2O3/water nanofluids. Both Al2O3 nanoparticles and CNTs are dispersed in the base fluid with equal solid volume. Experiments were conducted with various solid volume fractions of 0.02, 0.04, 0.1, 0.2, 0.4, 0.8 and 1.0 % and...

The conditions of occurring heat flux splitting (bifurcation) phenomenon in a micro-channel filled with a porous medium including internal heat generations within both the solid and fluid phases under the local thermal non-equilibrium (LTNE) condition is analytically studied in the slip regime. The channel walls are subjected to a constant heat flu...

The energy crisis has led humankind to drastically think about optimization of facilities which are in closed connection with energy resources. Therefore, optimization of thermal systems from heat transfer point of view, to decrease heat losses and therefore energy consumption, is an explicit goal in the field of thermal sciences. This work is abou...

In the current paper, heat transfer phenomenon within a living tissue subjected to a transient heat flux is studied. The Dual Phase Lagging (DPL) non-Fourier heat conduction model is used for thermal analysis. The thermal conductivity is assumed temperature-dependent which results in a non-linear equation. The obtained equations are solved by using...

This paper focuses on designing an artificial neural network which can predict thermal conductivity and dynamic viscosity of ferromagnetic nanofluids from input experimental data including temperature, diameter of particles, and solid volume fraction. The experimental data were extracted and they were used as learning dataset to train the neural ne...

Combined conduction-convection-radiation heat transfer is investigated numerically in a micro-channel filled with a saturated cellular porous medium, with the channel walls held at a constant heat flux. Invoking the velocity slip and temperature jump, the thermal behaviour of the porous-fluid system are studied by considering hydrodynamically fully...

A series of experiments have been carried out to determine the thermal conductivity and viscosity of a novel nanofluid, i.e., Mg(OH)2/ethylene glycol (EG). The thermal conductivity and viscosity of nanofluids with volume fractions by 2 % in the temperature range of 25-55 °C are measured. The results unfold that in the temperature of 35 °C, called c...

Energy consumption and its efficient utilization are two important factors of thermal systems. This work concerns with numerical and experimental studies about the surface radiation and natural convection effects on the heat transfer and flow field between two finite concentric cylinders, using one radiation shield between them. This study reveals...

Constrained fluid flow and conjugate heat transfer in microchannel heat sinks (MCHS) with converging channels are investigated using the finite volume method (FVM) in the laminar regime. The maximum pressure of the MCHS loop is assumed to be limited due to constructional or operational conditions. Results show that the Poiseuille number increases w...

In the present study, the thermal conductivity of the ZnO-EG nanofluid has been investigated experimentally. For this purpose, zinc oxide nanoparticles with nominal diameters of 18 nm have been dispersed in ethylene glychol at different volume fractions (0.000625, 0.00125, 0.005, 0.01, 0.015, 0.02, 0.03, 0.04, and 0.05) and temperatures (24-50 °C)....

In the present paper, the heat transfer phenomenon was studied inside pancreatic tissue under the influence of a constant heat flux of the laser beams. Various models of heat transfer were used in order to obtain a suitable model. In the case of temperature-dependent properties, nonlinear equations were derived. A finite difference numerical method...

This paper studies an analytical method which combines the superposition technique along with the solution structure theorem such that a closed-form solution of the hyperbolic heat conduction equation can be obtained by using the fundamental mathematics. In this paper, the non-Fourier heat conduction in a slab at whose a left boundary there is a co...

In the present study, the dynamic viscosity of the Mg(OH)2-ethylene glycol(EG) nanofluid is investigated. The studied nanofluid in different solid volume fractions of 0.1%, 0.2%, 0.4%, 0.8%, 1%, 1.5% and 2% at the temperatures of 23 and 55⁰C with diameter particle size of 10 nanometer are measured. In addition, by investigating the shear rate of th...

In this paper, the efficiency of Fe/ethylene glycol nanofluids as coolants is investigated in both laminar and turbulent flow regimes. The effects of particle size, temperature and concentration of nanofluids on the efficiency are examined. To determine the efficiency of nanofluids, the thermal conductivity and viscosity of the nanofluids with conc...

This paper is a continuation of the authors' previous work on the thermophysical properties, heat transfer, and pressure drop of nanofluids [Experimental Thermal and Fluid Science 52 (2014) 68–78]. In this paper, an experimental study is carried out to study the turbulent flow of COOH-functionalized multi-walled carbon nanotubes/water nanofluid flo...

The application of nanofluids in energy systems is developing day by day. Before using a nanofluid in an energy system, it is necessary to measure the properties of nanofluids. In this paper, first the results of experiments on the thermal conductivity of MgO/ethylene glycol (EG) nanofluids in a temperature range of 25-55 A degrees C and volume con...

A considerable number of studies can be found on the thermal conductivity of nanofluids in which Al2O3 nanoparticles are used as additives. In the present study, the aim is to measure the thermal conductivity of very narrow Al2O3 nanoparticles with the size of 5 nm suspended in water. The thermal conductivity of nanofluids with concentrations up to...

In this paper, an experimental study is performed to assess the heat transfer characteristics and pressure drop of low concentrations of a new class of nanotubes, i.e. COOH-functionalized double-walled carbon nanotubes (DWCNTs) suspended in water under turbulent flow in a double tube heat exchanger. First, the thermal conductivity and viscosity of...

This paper presents an experimental investigation of the effect due to temperature and particle volume concentration on the dynamic viscosity of ZnO-EG nanofluid. The viscosity of Zinc Oxide nanoparticles with mean diameter of 18 nm dispersed in ethylene glycol was determined using a ‘Spindle-type’ Brookfield commercial viscometer for temperatures...

Thermal processing of metals may be moving, as in hot rolling, forging or extrusion, to shape materials in standard forms such as plates, sheets, rods, tubes and structural sections. The purpose of the present paper is to analyze the problem of convective–radiative heat transfer from a continuously moving plate with multiple nonlinearities. The the...

Rheological characteristics of Al2O3, CuO and TiO2 nano particles were investigated in oil as the base fluid at 1 and 2 wt.%. Constitutive relations for non-Newtonian fluid were discussed based on the power-law model. Measured viscosities of each nanofluid were used to evaluate the power-law index and consistency index. Results indicated that the n...

This study focuses analytically on the local thermal non-equilibrium (LTNE) effects in the developed region of forced convection in a saturated porous medium bounded by isothermal parallel-plates. The flow in the channel is described by the Brinkman–Forchheimer-extended Darcy equation and the LTNE effects are accounted by utilizing the two-equation...

The addition of nanoparticles to a base fluid is one of the significant issues to enhance heat transfer. In this study, different nanofluids were developed by mixing a water base fluid with magnetic nanoparticles. Thermophysical properties such as thermal conductivity and viscosity of the obtained nanofluid were investigated. The effect of differen...

In the present paper results of an experimental study on thermal conductivity, dynamic viscosity and Nusselt number of turbulent forced convection of Magnesium Oxide–water nanofluid in a circular straight pipe is presented. The considered pertinent parameters are Reynolds number, nanoparticles volume fraction and nanoparticles diameter. The pure wa...

Non-Fourier heat conduction in a slab with nonhomogeneous boundary conditions is investigated analytically. In this research, the solution structure theorems, along with the superposition technique, are applied to obtain a closed-form solution of the hyperbolic heat conduction (HHC) equation using fundamental mathematics. In this solution, a compli...

Forced and natural convection in porous fins with convective coefficient at the tips under radiation and convection effects are investigated in this paper. Aluminum and copper as fin materials are investigated. In forced and natural convection, air and water are applied as working fluids, respectively. In order to solve this nonlinear equation, Hom...

This paper develops a numerical study of the transient response of a radiation heat shield inserted between two plane, gray, parallel, rectangular surfaces of emissivities ${\varepsilon_1 }$ ε 1 and ${\varepsilon_2 }$ ε 2 . All radiating surfaces have identical dimensions. The radiation shield is assumed to have different emissivities on it...

In the present paper, mixed convection fluid flow and heat transfer in a ventilated square cavity containing two heated blocks has been investigated numerically. The cavity subjected to an external Al2O3–water nanofluid while temperature and nanoparticles concentration dependent on thermal conductivity and effective viscosity inside a square enclos...

This article presents a numerical investigation of turbulent flow in an axisymmetric separated and reattached flow over a longitudinal blunt circular cylinder. The governing equations were discretized by the finite-volume method and SIMPLER method was applied to solve the equations on a staggered grid. The turbulent flow was numerically simulated u...

In this paper, porous fin has been studied and its nonlinear ordinary differential equation has been solved through homotopy perturbation method. In this method, a homotopy is introduced to be constructed for the equation. The initial approximations can be freely chosen with possible unknown constants, which can be determined by imposing the bounda...

To study the mixed convection flows in a square double lid-driven cavity with various inclination angles, a numerical method based on the finite volume method is used. In this investigation Al2O3/water nanofluid with particle diameter of 47 nanometers in different solid volume fractions have been utilized. Flow is obtained by the top and bottom wal...

This work introduces a simple method of analysis to study the performance of porous and solid fins in a natural convection environment. The method is based on using energy balance and Darcy's model to formulate the heat transfer equation. This study is based on long fin tip. The porous fin allows the flow infiltrate through it. The theory section a...

This work introduces a simple method of exergy analysis in a typical circular porous fin. The entropy generation of any thermodynamic system provides a useful measure of the extent of irreversibility. The irreversibility causes the loss of useful work (exergy) in the system and hence the loss of exergy has to be minimized. Entropy generation is a p...

The radiation network method has been applied to calculate the net radiation heat transfer between two concentric hemispheres separated by two hemispherical radiation shields with temperature-dependent surface emissivities. Three different materials are chosen for radiation shields: aluminum oxide, silicon carbide, and tungsten. The reduction in he...

Reducing the pressure of natural gas in city gate station will cause cooling around pressure reducer valve and so this help to formation gas hydrate in pipeline. In fact low temperature, existing water in pipeline and the presence of hydrate ingredients such as methane, ethane, and carbon dioxide…cause this process. Gas hydrate in gas transmission...

Reducing the pressure of natural gas in city gate station will cause cooling around pressure reducer valve and so this help to formation gas hydrate in pipeline. In fact low temperature, existing water in pipeline and the presence of hydrate ingredients such as methane, ethane, and carbon dioxide…cause this process. Gas hydrate in gas transmission...

The present paper relates to a method of heating natural gas in preparation for reduction in its pressure. In a natural gas distribution system, the gas generally travels from the field at relatively high pressure and velocity. In Iran's City Gate Station, water bath heater equipped with burner is used for heating gas flow. These equipments have ad...

In this paper, a simplifying approach for calculating the radiant energy is achieved using the concept of net radiation heat transfer and provides an easy way for solving a variety of situations. This method has been applied to calculate the net radiation heat transfer between two long concentric semi-cylinders. Then this method used to calculate r...

Analytical solutions play a very important role in heat transfer. Ill this paper, the He's homotopy perturbation method has been applied to non-linear convective-radiative non-Fourier conduction heat transfer equation with variable specific heat coefficient. The concept of the He's homotopy perturbation method are introduced briefly for applying th...

In this article, a further investigation on the integral solution of the boundary layer momentum equation, which is originally concerned by von Karman and Pohlhausen, is done. According to various profiles that we suggest, an analysis on the errors in values of the boundary layer thickness, * and friction coefficient, C , is drawn. Although it is e...

The purpose of the present paper is to carry out the non-Fourier effect subjected to a special heat-flux boundary condition. The governing equation is expressed in cylindrical coordinates and is solved by deriving the analytical solution. The temperature layers and profiles of sample calculations are performed. It is found that, as much as the Vern...

Radiation is one of the most important modes of heat transfer. In this study, a simplifying approach for calculating the radiant energy is achieved using the concept of net radiation heat transfer and provides an easy way for solving a variety of situations. This method has been applied to calculate the net radiation heat transfer between two conce...

In this paper, a variational iteration method (VIM) has been applied to nonlinear non-Fourier conduction heat transfer equation with variable specific heat coefficient. The concept of the variational iteration method is introduced briefly for applying this method for problem solving. The proposed iterative scheme finds the solution without any disc...

The purpose of the present paper is to carry out the non-Fourier effect subjected to heat flux boundary condition. The governing equation expressed in cylindrical coordinates. Equations are solved by deriving the analytical and the numerical solution. The temperature layers and profiles of sample calculations are performed. It is found from these c...

The purpose of the present paper is to investigate the hyperbolic heat conduction subjected to heat flux boundary conditions. The governing equation is expressed in cylindrical coordinates. Equations are solved by deriving the analytical and the numerical solutions. The temperature layers and profiles of sample calculations are presented. It is fou...

Reducing the pressure of natural gas in city gate station will cause cooling around pressure reducer valve and so this help to formation gas hydrate in pipeline. In fact low temperature, existing water in pipeline and the presence of hydrate ingredients such as methane, ethane, and carbon dioxide cause this process. Gas hydrate in gas transmission...

A simplifying approach for calculating the radiant energy is achieved using the concept of net radiation heat transfer and providing an easy way for solving a variety of situations. This method has been applied to calculate the net radiation heat transfer between two concentric cylinders with and without radiation shield between them. Moreover, usi...

In this study, heat transfer by natural convection in domestic freezer without ventilation was carried out. The freezer was analyzed in a loaded condition by product. Both experimental and numerical (CFD software) approaches were used. The following conditions were assumed: constant evaporator temperature, three-directional laminar air flow. CFD si...

This paper describes a Variable Structure Model Reference Adaptive Control (VS - MRAC) for active steering assistance of a two wheel steering vehicle. Its main goal is to avoid lane departures. The controller steers an equipped vehicle along a specially marked lane without cross-over lane markings. The stability of the system is checked by lyapunov...

This paper describes a Variable Structure Model Reference Adaptive Control (VS – MRAC) for active steering assistance of a four-wheel steering vehicle, that angle of the rear wheels are coefficient of angle of the front wheels. Its main goal is to avoid lane departures. The controller steers an equipped vehicle along a specially marked lane without...

Analytical solutions play a very important role in all modes of heat transfer. In this work a simplifying approach for calculating the radiant energy is achieved using the concept of net radiation transfer and provides an easy way for solving a variety of situations. To be more precise, the objective of this paper is to calculate the net radiation...

The main aim of this paper is to obtain some possibly explicit analytical solution of the (1+3)-dimensional hyperbolic heat conduction equation for given initial and boundary condition with the method of separation of variables. The temperature layers and profiles for various relaxation times in three different examples are calculated. Also, the re...

Nonisothermal crystallization kinetics of polypropylene (PP) nanocomposite reinforced with 0.5 wt. % single-walled carbon nanotubes (SWNT) was characterized by differential scanning calorimetry at five different cooling and heating rates. The Avrami, Ozawa, and Seo-Kim kinetic models were used to describe the nonisothermal crystallization of the po...

In this work, polypropylene (PP) matrix reinforced with several single-walled carbon nanotubes (SWNTs) concentrations were prepared by a melt-mixing method. The effect of SWNTs on the thermal degradation behavior of polypropylene was studied by thermal gravimetric analysis. The results revealed that adding the SWNTs into the PP can increase the dec...

In the present work, the effect of different acid treatment times of single-walled carbon nanotubes (SWNTs) on the mechanical and thermal properties of polypropylene (PP)/maleated polypropylene (PP-g-MA) nanocomposites was investigated. The acid treatment process was based on a mixture of concentrated sulphuric and nitric acids. The SWNTs were trea...

High frequency selective electrical discharge sintering (HFSEDS) is a new method of rapid prototyping (RP). In HFSEDS, by using a relatively inexpensive machine, physical and functional parts, tools and masters can be built. This paper presents two essential subjects in HFSEDS. At the first, a brief overview of innovation, development and research...

Heat transfer in coated powder particles used as raw material in selective electrical discharge sintering is investigated numerically through the finite-volume method during the binding stage. In this stage, the thermal energy of the plasma arc is distributed to all of the nodes of coated powder by conduction. Transient heat transfer analysis in sp...

In the last decades, several experiments have shown that the classical theory of heat conduction in solids based on Fourier's law may fail when unsteady pro-cesses are involved. Indeed, the parabolic heat im-plies an infinite propagation speed of the heat wave. In situations which include extremely high temper-ature gradients, extremely large heat...