Vertical Parallel Research Articles

The Influence of Inclined Magnetic Field and Heat Transfer on the MHD Convective Flow in a Vertical Channel Filled Partly with Porous Medium

An analyticstudy has been madeof a laminar fully developed MHD flow bounded by infinite vertical parallel plates with effect of inclined magnetic fieldpartly filled with fluid and partly with porous matrix. The motions of the plates are in the opposite direction and are maintained at distinct temperatures. The perturbation method has been chosen to derive the expression for velocity flow and temperaturedistributionand the effect on flow velocity and temperature due to magnetic field and Darcy number has been illustrated for the fluid and porous region with the helpof graph.

Secondary Convection Regimes in a Fluid with a Temperature-Dependent Viscosity in a Plane Vertical Layer

In this work, secondary convection regimes in a. fluid with a. viscosity linearly dependent on temperature, enclosed between two vertical parallel planes heated to different temperatures, are studied. The boundaries of the layer were considered hard and perfectly heat-conducting. The problem was solved numerically by the finite difference method. Calculations were carried out for Prandtl numbers equal to one and twenty. In the first case, in a. fluid with constant viscosity, the loss of stability of the main flow is related to the development of hydrodynamic perturbations, which comprise motionless vortices at the boundary of the counter flows. In the second case, the instability of the main flow is caused by oscillatory perturbations, which comprise thermal waves. Dependences of the Nus-selt number on the Grashof number and data on the structure of the secondary flows are obtained. It is found that, if the Prandtl number is equal to unity, the Nusselt number monotonically increases with the Grashof number and, near the instability threshold of the main flow, it increases according to the root law; i.e., the secondary flow arises softly. The secondary structures look like drifting vortices at the boundary of counter flows, which, after a. transient process, leads to the establishment of steady oscillations of the heat flux. At a. Prandtl number of twenty, the relationship of the Nusselt number with the Grashof number is nonmonotonic; the curve contains sections in which the Nusselt number is equal to unity and sections in which the Nusselt number increases/decreases with increasing Grashof number. This behavior is explained by the fact that, for the Prandtl number equal to twenty, there are two instability modes; oscillatory and monotonic, and the region of increasing oscillatory perturbations with a. fixed wavenumber is bounded both above and below.

RELAP5-3D Three-Dimensional Analysis Based on PHÉNIX Dissymmetric Transient Test

Abstract Before the final shutdown of the PHÉNIX fast reactor, the CEA carried out a final set of experimental tests to gather data and additional knowledge on relevant sodium fast reactors (SFR) operation and safety aspects. One of these experiments conducted was the dissymmetrical configuration test, which was selected as benchmark transient within the H2020 SESAME project. ENEA and Sapienza University of Rome are participating in the benchmark using the RELAP5-3D© code. The thermal hydraulic analysis focuses on adequate core cooling prediction in accidental scenario. With the goal of investigating asymmetric thermal hydraulic behavior inside of the reactor pool, two different nodalization approaches have been applied for the RELAP5-3D model, which adopt the same geometrical scheme for the primary flow path, with the exception of the hot and cold pools and the core bypass. The first scheme has been developed using vertical parallel pipes with cross junctions for the hot and cold pools and an equivalent pipe to reproduce the core bypass. The second model includes a multidimensional (MULTID) component, which simulates the pools and provides a detailed nodalization of the core bypass. This study aims at assessing whether the two modeling approaches are equally capable to predict the asymmetrical temperature evolution over the test, caused by the azimuthal asymmetry of the boundary conditions. Blind calculation results are presented and discussed. The paper will be a first step toward the RELAP5-3D code assessment against the experimental results collected as part of the PHÉNIX dissymmetric test.

Mixed Convective Flow of a Visco Elastic Fluid Between Two Porous Parellel Plates

A diagnostic answer for the problem of sincerely grew loose convective circulation between two vertical parallel plates has been inspected in this paper. The trademark highlights of various parameters were talked about in element. it's miles considered that to be the Grashoff huge variety declines, the profiles are more and more illustrative in nature. Likewise, due to the fact the Grashoff range reductions the charge of the liquid medium increments. it is found that, the pinnacle pace is type of organized at a median separation most of the circulate geometry. similarly, as the Grashoff amount reductions, the imply essential thrust gives off an influence of being step by step main as impact of which the liquid movements quicker within the middle locale. Likewise, it is visible that, the speed increments because the Prandtl quantity discounts. in addition, it is considered that to be the Prandtl variety expands the mass transition diminishes. The mass transition is absolutely constrained thru the parameters, for instance, Reynolds range and Prandtl amount. The flow into supporter in each the instances does no longer differs lots. All above said outcomes and delineations accommodate with the outcomes built up by manner of M. Sajid, I. Pop, T. Hayat

Generation of Frequent sensor epochs using efficient Parallel Distributed mining algorithm in large IOT

Numerous data mining algorithms are implemented using huge volume of sensor data to generate the frequent item sets that are useful in many aspects such as to predict the behavioural sensor patterns of future events and to detect the survival of sensors in large IOT . Traditional data mining algorithms transactional databases to produce the frequent patterns. Since the rate of input data arrival in large IOT varies, it becomes difficult to mine the dynamic sensor database. This work proposes an efficient algorithm known as Vertical Partitioning Parallel Distributed Algorithm(VPPDA) that uses MapReduce framework to mine sensor epochs to detect the survival of sensors using association rules formed by generated frequent patterns. The proposed VPPDA eliminates overhead of interprocess communication, by introducing overlapped window concept implemented in MapReduce framework combined with Vertical partitioning approach to get better progress in execution time and accurate results. Additionally pipelining processing has been implemented in MapReduce framework that still increases the performance and generates the frequent sensor epochs patterns. The concept of pipeline processing was introduced to minimize the execution time and also make the situation adaptable to any input rate of incoming sensor epochs.

Inclined Magnetic Field, Thermal Radiation, and Hall Current Effects on Mixed Convection Flow Between Vertical Parallel Plates

Abstract This analysis studies the impact of an inclined magnetic field, hall current, and thermal radiation on fully developed electrically conducting mixed convection flow through a channel. The governing equations are nondimensionalized. The resulting system of nonlinear ordinary differential equations is solved utilizing spectral quasi-linearization method. Impact of all the pertaining flow parameters of this study on all the dimensionless profiles was calculated and presented through plots. Also, the nature of the physical parameters was calculated and presented in table form. This study clearly exhibits that the inclined magnetic field influences the fluid flow remarkably.

Natural convection of bio-nanofluid between two vertical parallel plates with damped shear and thermal flux

In this article, we studied the nature (free) convection flow of bio-nanofluid between two vertical plates. We developed a fractional model in which the classical constitutive equations are generalized by using the constitutive shear stress equation and the generalized Fourier’s law. The solutions of fractional differential equations are found by means of integral transforms (Laplace and sine-Fourier transforms). Solutions are expressed in terms of generalized G-function of Lorenzo and Hartley and Mittag-Leffler function. We compare our results with numerical methods. The effects of fractional and physical parameters are graphically discussed.

A modified Dickson’s charge pump circuit with high output voltage and high pumping efficiency

A modified Dickson’s charge pump circuit with high output voltage and high pumping efficiency fabricated by IHP’s 130 nm SiGe BiCMOS process is proposed. Instead of traditional on-chip metal–insulator–metal capacitor, a modified vertical parallel plate capacitor is utilized as the pumping capacitor, which owns a breakdown voltage higher than 84 V and an improved capacitance density of 1.92 fF/μm2. Thus, the output voltage and chip size of charge pump circuit are not limited by the pumping capacitor. To further improve the voltage pumping efficiency and make the circuit suitable for low voltage operation, the threshold voltage and the body effect coefficient is eliminated by using a dynamic control to both the charge transfer switches and the MOSFETs body voltages. Simulated result of a 35-stage charge pump circuit with an output voltage higher than 100 V is demonstrated. A 7-stage charge pump circuit with an output voltage of 13.8 V and a pumping efficiency of 75%, higher than the traditional Dickson’s charge pump circuits, is fabricated and measured.

Hydromagnetic free convection flow of viscous fluid between vertical parallel plates with damped thermal and mass fluxes

In this article, hydromagnetic free convection flow of viscous fluid between two vertical plates is considered. The Caputo time-fractional derivative is used and the governing equations are fractionalized by means of generalized Fourier’s and Fick’s laws. Laplace transform coupled with the finite sine-Fourier transform which is suitable to problems with boundary conditions. Closed form general solutions are expressed in terms of Mittag-Leffler function. The effects of fractional parameters as well as physical parameters are plotted graphically.

Analysis of Natural Convection Bionanofluid Between Two Vertical Parallel Plates

In this paper, natural convection flow of non-Newtonian bionanofluid flow between two vertical flat plates is considered. Sodium alginate (SA) is considered the base non-Newtonian fluid, and nanoparticles such as titania (TiO2) and alumina (Al2O3) were added to them. Analytical solutions for temperature and velocity field are determined by means of integral transform (Laplace transform) method. The influences of some physical parameters non-dimensional velocity and temperature profiles are graphically underlined.

Unsteady Free Convection Flow between Two Vertical Parallel Plates with Newtonian Heating

Free convection flow in a boundary layer region is a motion that results from the interaction of gravity with density differences within a fluid. These differences occur due to temperature or concentration gradients or due to their composition. Studies pertaining free convection flows of incompressible viscous fluids have received much attention in recent years both theoretically (exact or approximate solutions) and experimentally. The situation where the heat be transported to the convective fluid via a bounding surface having finite heat capacity is known as Newtonian heating (or conjugate convective flows). In this paper, the unsteady free convection flow of an incompressible viscous fluid between two parallel plates with Newtonian heating is studied. Appropriate non-dimensional variables are used to reduce the dimensional governing equations along with imposed initial and boundary conditions into dimensionless forms. The exact solutionsfor velocity and temperature are obtained using the Laplace transform technique. The corresponding expressions for skin friction and Nusselt number are also calculated. The graphical results are displayed to illustrate the influence of various embedded parameters such as Newtonian heating parameter and Grashof number. The results show that the effect of Newtonian heating parameter increases the Nusselt number but reduces the skin friction.

Shape Effect in Magnetohydrodynamic Free Convection Flow of Sodium Alginate-Ferrimagnetic Nanofluid

This article presents the generalization of the unsteady MHD free convection flow of non-Newtonian sodium alginate-ferrimagnetic nanofluid in two infinite vertical parallel plates. The different shape (blade, brick, cylinder, and platelet) ferrimagnetic nanoparticles are dissolved in the non-Newtonian sodium alginate (SA) as base fluid to form non-Newtonian nanofluids. The Jeffrey fluid model together with energy equation is considered to demonstrate the flow. The Atangana–Baleanu fractional operator is utilized for the generalization of mathematical model. The Laplace transform technique and Zakian's numerical algorithm are used to developed general solutions with a fractional order for the proposed model. The obtained results are computed numerically and presented graphically to understand the physics of pertinent flow parameters. It is noticed that the velocity and temperature profiles are significantly increased with the increasing values of the fractional parameter due to the variation in thermal and momentum boundary layers. In the case of the effect of different shapes of nanoparticles, density is a dominant factor as compared to thermal conductivity, which significantly affects the flow of non-Newtonian nanofluid.

Effect of Variable Viscosity on Natural Convection Flow Between Vertical Parallel Plates in the Presence of Heat Generation/Absorption

The present article was aimed at investigating the effects of variable viscosity on natural convection flow between vertical parallel plates in the presence of heat generation/absorption. The nonlinear differential equations governing the flow were solved using Homotopy perturbation method. The impacts of the several governing parameters on the velocity and temperature profiles are presented graphically and values of skin friction, rate of heat transfer, mass flux and mean temperature for various values of physical parameters are presented through tables. In the course of computation, it was revealed that viscosity ontributes to decrease velocity and hence reduced resistance to flow. It was also discovered that as the heat generation increases, fluid temperature and velocity increase, while it decrease with the increase in heat absorption. Finally, it was concluded that the skin friction on both plates increase as viscosity increases.

Free convection flow of nanofluids between two vertical plates with damped thermal flux

In this article, we consider the transient free convection flow of nanofluids between two vertical parallel plates in the presence of radiation and damped thermal flux. The generalized Fourier's law is considered in thermal flux constitutive equation with a weakly memory. The integral transform technique is used for finding the exact solutions of the fractional governing differential equations for fluid temperature and velocity field. The solutions are presented in the term of the time-fractional derivative of the Wright function and Robotnov and Hartley function. Solutions to the ordinary fluid, corresponding to the fractional parameter equal to unit, are obtained as a particular case of the fractional problem. Numerical calculations are carried out and results are presented in graphical illustrations. The influence of the memory parameter (the fractional order of the time-derivative) on the temperature and velocity fields is analyzed and a comparison between the fluid with thermal memory and the ordinary fluid is made.

Transient MHD Convective Flow of Fractional Nanofluid between Vertical Plates

Effects of the uniform transverse magnetic field on the transient free convective flows of a nanofluid with generalized thermal transport between two vertical parallel plates have been analyzed. The fluid temperature is described by a time-fractional differential equation with Caputo derivatives. Closed form of the temperature field is obtained by using the Laplace transform and fractional derivatives of the Wright’s functions. A semi-analytical solution for the velocity field is obtained by using the Laplace transform coupled with the numerical algorithms for the inverse Laplace transform elaborated by Stehfest and Tzou. Effects of the derivative fractional order and physical parameters on the nanofluid flow and heat transfer are graphically investigated.

G-JITTER INDUCED MIXED CONVECTION FLOW BETWEEN TWO PARALLEL PLATES WITH NEWTONIAN HEATING

This article deals with the mixed convection flow between two vertical parallel plates with the effect of g-jitter. Newtonian heating is considered on the left wall of the plate. The governing equations of heat and mass transfer are modelled in the Cartesian coordinate system with the effect of g-jitter. Non-dimensional variables are used to transform the governing equations together with the boundary layer condition. Separation of variables method are applied to provide the exact analytical solutions for the velocity, temperature and concentration profiles. The obtained solutions are computed to produce the graphical results. It is showed that due to an increasing value of wall temperature and thermal conjugate parameter, the fluid temperature increased. As wall concentration increases, the fluid concentration also increased. Meanwhile, the velocity increasing as mixed convection and thermal conjugate parameter increased. Contradict, the velocity decreasing as the value of buoyancy ratio and frequency increased.

Pulsed Flow in a Vertical Channel with Discrete Heat Sources

This work is a numerical simulation of pulsed flow in an adiabatic vertical parallel plate channel with four discrete heat sources on one wall of the channel and subjected to a sinusoidal profile velocity at the inlet. The finite volume method was used to solve governing equations using open source OpenFoam free code. The effects of certain topical parameters such as pulsation amplitude and frequency and Richardson number are studied. The results reveal the flow behaviour and temperature distribution are strongly affected by the pulsation of the velocity at the inlet and the rate of heat transfer during a pulsation cycle increases considerably by increasing the pulsation amplitude.

Free Convection MHD Couette Flow with Application of Periodic Temperature and Constant Heat Flux on Walls

Numerical analysis and analytical solution were performed to study the free convection in transient Couette flow of an electrically conducting fluid confined between two vertical parallel plates. Constant heat flux on the wall with uniform vertical motion in its own plane and periodic temperature on the stationary wall were applied. The dimensionless governing momentum and energy equations are solved numerically using a fully implicit finite difference method. An analytical solution using eigenfunction expansion method is carried out for temperature profile in case of constant plate temperature. Analytical and numerical results converge at a satisfactory degree. The effect of different physical parameters on the transient velocity and temperature, such as Grashof’s number (Gr), magnetic parameter (M), Prandtl number (Pr) and temperature frequency are also studied. It is found that the velocity increases with an increase in Gr and temperature frequency, while it decreases with an increase in Pr and M.

Natural convection of non-Newtonian nanofluid flow between two vertical parallel plates

PurposeThe purpose of this paper is to carry out a detailed investigation to study the natural convection of a non-Newtonian nanofluid flow between two vertical parallel plates. In this study, sodium alginate has been taken as a base fluid and nanoparticles that added to it are copper and silver. Maxwell–Garnetts and Brinkman models are used to calculate the effective thermal conductivity and viscosity of nanofluid, respectively.Design/methodology/approachThe authors used two methods in this study, namely, Galerkin’s method and homotopy perturbation method.FindingsThis paper investigates the velocity and temperature profile of nanofluid and the real fluid flow between two vertical parallel plates. The impacts of physical parameters such as nanofluid volume fraction and dimensionless non-Newtonian viscosity are discussed.Originality/valueCoupled non-linear differential equations are solved for velocity and temperature. A model is proposed in such a way that the authors may get the solution of real fluid from the nanofluid by neglecting the nano term. The authors do not require a further calculation for real fluid problem.

Temperature and Location of Hot Spots Variation with Spacing in a Vertical Parallel Plate Channel: Conjugate View

Temperature and Location of Hot Spots Variation with Spacing in a Vertical Parallel Plate Channel: Conjugate View