Nusselt Number Research Papers - Academia.edu (original) (raw)

This article investigates the Hall and ion‐slip impacts on the mixed convection flow of a Maxwell nanofluid over an expanding surface in a permeable medium. The impacts of Brownian movement and thermophoresis parameters, Soret, Dufour, viscous dissipation, chemical reaction, and suction parameters, are, moreover, considered. Using the similitude changes, the partial differential equations with regard to the momentum, energy, and concentration equations are transformed to an arrangement of nonlinear ordinary differential equations, which are handled numerically utilizing a spectral relaxation method (SRM). The impacts of noteworthy physical parameters on the velocities, thermal, and concentration distributions are investigated graphically. Moreover, the numerical values of skin‐friction coefficients, local Nusselt number, and Sherwood number for different values of the mixed convection parameter Deborah number Hall parameter ion‐slip parameter Dufour number (Du), and Soret number are...

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- Materials Science, Mechanics, Convection, Heat Transfer

In this article, the Hall and ion-slip effects on a mixed convection flow of an electrically conducting nanofluid over a stretching sheet in a permeable medium have been discussed. Using the similarity transformations, the partial differential equations corresponding to the momentum, energy, and concentration equations are transformed to a system of nonlinear ordinary differential equations which are solved numerically using a spectral relaxation method (SRM). The effects of significant parameters on the velocities, temperature, and concentration profiles are analyzed graphically. Moreover, the results of the skin friction coefficients, local Nusselt number, and Sherwood number are determined numerically. The results of the analysis showed that the velocity profile in the flow direction increases with an increase in mixed convection parameter λ, Hall parameter βh, and ion-slip parameter βi, and it decreases with an increase in the magnetic parameter M. Furthermore, temperature and c...

- by Temesgen Anbessa
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- Mathematics, Nanofluid, Buoyancy, Nusselt Number

The intention of the present study is to scrutinize the three-dimensional MHD mixed convection flow of Casson nanofluid over an exponentially stretching sheet using the impacts of Hall and ion slip currents. Moreover, the impacts of thermal radiation and heat source are considered in this study. The governing partial differential equations are transformed into a system of joined nonlinear ordinary differential equations using similarity transformations, and they are solved numerically employing a spectral relaxation method (SRM). The obtained results are contrasted with existing specific cases, and a reasonable harmony is established. The impacts of noteworthy physical parameters on the velocities, thermal and concentration distributions, skin friction coefficients, local Nusselt number, and local Sherwood number are investigated graphically. It is found that the rise in Casson fluid and magnetic field parameters reduce the velocity profiles along bothx−andy−directions while the rev...

- by Temesgen Anbessa
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- Engineering, Materials Science, Magnetohydrodynamics, Mathematical Sciences
- by zeev dagan
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- Engineering, Physics, Materials Science, Mechanics
- by Nidhal Ben Khedher
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- Materials Science, Mechanics, Heat Transfer, Nusselt Number

This article deals with the impact of including transverse ribs within the absorber tube of the concentrated linear Fresnel collector (CLFRC) system with a secondary compound parabolic collector (CPC) on thermal and flow performance coefficients. The enhancement rates of heat transfer due to varying governing parameters were compared and analyzed parametrically at Reynolds numbers in the range 5,000–13,000, employing water as the heat transfer fluid. Simulations were performed to solve the governing equations using the finite volume method (FVM) under various boundary conditions. For all Reynolds numbers, the average Nusselt number in the circular tube in the CLFRC system with ribs was found to be larger than that of the plain absorber tube. Also, the inclusion of transverse ribs inside the absorber tube increases the average Nusselt number by approximately 115% at Re = 5,000 and 175% at Re = 13,000. For all Reynolds numbers, the skin friction coefficient of the circular tube with r...

- by Nidhal Ben Khedher
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- Materials Science, Mechanics, Heat Transfer, Nusselt Number
- by trushar gohil
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- Mechanical Engineering, Applied Mathematics, Physics, Mechanics

The influence of Lorentz force on the heat propagation in the conjugate cavity with various Rayleigh number (Ra) and Hartmann number (Ha) is explored in this study. The conjugate thermal and electromagnetic coupling is considered for the fluid-wall interface in the present analysis and includes the wall thickness within the computational domain. The computation of electric potential field and conduction heat transfer is enabled in the wall domain. The numerical code for conjugate buoyancy-driven convective flow with magnetohydrodynamics principle is developed on the open source platform OpenFOAM. The developed solver is capable to simulate steady and unsteady flows on complex geometry. The influence of thermal Rayleigh number (Ra) on the fluid flow is also investigated in this study for different Ra range. The outer vertically opposite side walls are kept isothermal and remaining outer walls are maintained as thermally insulated. The inner vertically opposite walls are kept thermall...

- by trushar gohil
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- Engineering, Physics, Materials Science, Mechanics
- by trushar gohil
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- Mechanical Engineering, Applied Mathematics, Physics, Mechanics
- by Sirak Tsegaye Yimer
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- Mathematics, Physics, Materials Science, Mechanics

This paper explores the potential of a cylindrical enclosure with vent holes to create and maintain the desired thermal environment for indoor farming. Different thermal zones can be made in a single room when such enclosures are used in multiple numbers in a single room. A comparative analysis of twelve different air cooling/heating configurations was conducted. Each cylindrical enclosure is air-filled, with two heat sinks facing each other and vent holes in the top and bottom surfaces. Six configurations had heat sinks oriented vertically, and the other six had heat sinks inclined at 45°. These configurations (vertical and inclined heat sinks) have been studied for different heat sink temperatures and sidewall heat flux conditions. The numerical simulations were conducted using ANSYS-Fluent. The studies have shown that different thermal environments can be created inside the enclosure, and cooling can be achieved with sufficient air exchange through vent holes. The instabilities due to buoyancy-driven flow are found to be necessary for air exchange through vent holes. Validation studies have shown that the heat flux from the sidewall should be considered, even if it is an excellent thermal insulator.

- by Hanxing Zhu
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- Engineering, Mechanical Engineering, Materials Science, Thermal Resistance
- by Susan Mantell
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- Mechanical Engineering, Chemical Engineering, Materials Science, Mechanics

The effects of fluctuating temperature on Darcy-Forchheimer flow of oil-based nanofluid with activation energy and velocity slip has been analyzed. Similarity transformation was used to transform the governing partial differential equations into coupled nonlinear ordinary differential equations and solved numerically with the aid of the fourth order Runge-Kutta algorithm with a shooting technique. Results for the embedded parameters controlling the flow dynamics have been tabulated and illustrated graphically. The slip velocity parameter was found to enhance the Nusselt number but depleted both the skin friction coefficient and Sherwood number while the local inertial was noted to increase both the skin friction coefficient and Sherwood number but diminishes the Nusselt number. These results indicate that the velocity slip parameter and local inertial coefficient can be used to control flow characteristics in industrial and engineering systems.

- by Rabiu Musah
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- Mechanics, Nanofluid, PARTIAL DIFFERENTIAL EQUATION, Nusselt Number

In this current paper, an investigation has been conducted on the magnetohydrodynamic boundary layer flow of non-Newtonian Casson fluids on magnetized sheet with an exponentially stretching sheet. The similarity approach has been used to transform the governing models for Casson fluid to ordinary differential equations. We presented numerical results for momentum, energy and concentration equation parameters. Effects of the magnetized sheet and varying all the emerged parameters on the flow of Casson fluid with respect to the friction between the fluid and the surface, temperature and concentration are presented in tables. As a result of the induced magnetization of the sheet, the thickness of the thermal boundary layer has been enhanced. This behaviour brings a considerable reduction to the heat transfer. The induced magnetized sheet has a similar influence on the skin friction, Nusselt number and the Sherwood number. We however proposed incorporation of magnetized surfaces in MHD ...

- by Rabiu Musah
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- Materials Science, Mechanics, Magnetohydrodynamics, Heat Transfer
- by eric serre
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- Mechanical Engineering, Aerospace Engineering, Physics, Mechanics

This article presents a numerical methodology for predicting the overall heat transfer, the number of thermal units and the efficiency map of an engine radiator. Correlations to predict the air and water side heat transfer coefficients and friction factors as a function of the Reynolds number and geometric variables of the radiator are applied. The presented methodology for thermal analysis of heat engine radiator is based on the Kays and London theory. Nonlinear regressions are found to compute air-side Nusselt number, as well as water side heat transfer and friction factors.

- by Carlos romero
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- Engineering, Mechanics, Heat Transfer, Thermal
- by Yassir Makkawi
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- Physics, Materials Science, Mechanics, Heat Transfer
- by Amel Alaidrous
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- Materials Science, Mechanics, Heat Transfer, Medicine

The aim of this work is to discuss the effect of mth-order reactions on the magnetic flow of hyperbolic tangent nanofluid through extending surface in a porous material with thermal radiation, several slips, Joule heating, and viscous dissipation. In order to convert non-linear partial differential governing equations into ordinary ones, a technique of similarity transformations has been implemented and then solved using the OHAM (optimal homotopy analytical method). The outcomes of novel effective parameters on the non-dimensional interesting physical quantities are established utilizing the tabular and pictorial outlines. After a comparison with previous literature studies, the results were finely compliant. The study explores that the reduced Nusselt number is diminished for the escalating values of radiation, porosity, and source (sink) parameters. It is found that the order of the chemical reaction m = 2 is dominant in concentration as well as mass transfer in both destructive ...

- by Amel Alaidrous
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- Materials Science, Mechanics, Heat Transfer, Medicine
- by Demetrios Papageorgiou
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- Engineering, Mechanical Engineering, Chemical Engineering, Physics
- by Sadrul Islam
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- Materials Science, Thermodynamics, Heat Transfer, Nanofluid
- by Nald Erusiafe
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- Physics, Mechanics, Thermal Radiation, Boundary Layer

An Earth air heat exchanger(EAHE) usesnbsp the earth as the thermal source and sink for economical, energy efficient, space heating and cooling. The temperature of earth at a certain depth about 4m thenbsp temperaturenbsp ofnbsp groundnbsp remains nearly constant throughout the year.Thisnbsp constant temperature is called the undisturbed temperature of earthnbsp whichnbsp remainsnbsp higher than the outside temperature nbspinnbsp winternbsp andnbsp lowernbsp thannbsp thenbsp outside temperature in summer.When air is passing throught buried pipes it will become hot in winter and cold in summer as compared to outside temperature.EAHE generally uses for passive heating or cooling.This paper presents effect of temperature drop or rise due to fins in horizontal arrangement. In this paper comparsion of COP v/s Reynolds number,temp difference v/s Reynolds number and Nusselt number v/snbsp Reynolds number will be done.

- by Rahul Rahul rathee
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- Materials Science, Mechanics, Heat Exchanger, Thermal
- by Faisal Shah
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- Computer Science, Materials Science, Mechanics, Thermodynamics

In this work, convective heat transfer flow over a stretching / shrinking vertical sheet is
studied in relation to hazardous reactions, concentrations, and temperatures using nanoparticles. The
objective is to use MATLAB software's Bvp4c approach to transform the control linear ordinary
differential equations (PDEs) into an ordinary differential equations (ODEs) set for statistical
analysis. It is required to examine the interactions between a number of factors, including the Lewis
number, other bioconvection-related limitations, the concentration-thermal-buoyancy connection, the
chemical change constants and Prandtl numerals, and the rate of return between microorganisms and
thermal buoyancy. The bioconvection flow profiles, temperature, concentration, and velocity
numerical data are shown.

- by Dally Maria Evangeline A
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- Fuzzy Logic, Optimization techniques, Nano Fluids
- by joel Sommeria
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- Physics, Magnetohydrodynamics, Convection, Turbulence
- by joel Sommeria
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- Physics, Mechanics, Complex System, Mathematical Sciences

On considere une etude numerique tridimensionnelle de la convection naturelle bidiffusive dans une enceinte rectangulaire soumise a des gradients de temperature et de concentration horizontaux. L'ecoulement est entraine par les forces des poussees thermique et solutale. Les resultats obtenus montrent le caractere tri directionnel de l'ecoulement pres des paroisv isothermes et le caractere tridimensionnel de l'ecoulement pres des parois verticales adiabatiques. La variation du nombre de Grashof solutal a permis l’obtention de plusieurs types d’ecoulements et plusieurs bifurcations entre ces ecoulements. La convection transitoire et aperiodique se manifeste dans un intervalle de Grashof solutal entre 3×105 et 5×105.

- by Smail Benissaad
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- Physics, Grashof number

Steady, laminar, natural convection flow in a square enclosure with partially active vertical wall is considered. The enclosure is filled with air and subjected to horizontal temperature gradient. Finite volume method is used to solve the dimensionless governing equations. The physical problem depends on three parameters: Rayleigh number (Ra =103-106), Prandtl number (Pr=0.71), and the aspect ratio of the enclosure (A=1). The active location takes two positions in the left wall: top (T) and middle (M). The main focus of the study is on examining the effect of Rayleigh number on fluid flow and heat transfer rate. The results including the streamlines, isotherm patterns, flow velocity and the average Nusselt number for different values of Ra. The obtained results show that the increase of Ra leads to enhance heat transfer rate. The fluid particles move with greater velocity for higher thermal Rayleigh number. Also by moving the active location from the top to the middle on the left ve...

- by Smail Benissaad
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- Geology, Mechanics, Heat Transfer, Natural Convection

Steady, laminar, natural convection flow in porous square enclosure with inclination angle is considered. The enclosure is filled with air and subjected to horizontal temperature gradient. Darcy- Brinkman-Forchheimer model is considered. Finite volume method is used to solve the dimensionless governing equations. The physical problem depends on five parameters: Rayleigh number (Ra =103-106), Prandtl number (Pr=0.71), Darcy number (Da=0.01), inclination angle φ=(0°-227°), porosity of the medium (ε=0.7) and the aspect ratio of the enclosure (A=1). The main focus of the study is on examining the effect of Rayleigh number on fluid flow and heat transfer rates. The effect of inclination angle is also considered. The results including streamlines, isotherm patterns, flow velocity and the average Nusselt number for different values of Ra and φ. The obtained results show that the increase of Ra leads to enhance heat transfer rate. The fluid particles move with greater velocity for higher th...

- by Smail Benissaad
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- Materials Science, Mechanics, Heat Transfer, Natural Convection
- by Smail Benissaad
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- Materials Science, Mechanics, Heat Transfer, Magnetic field
- by Smail Benissaad
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- Engineering, Materials Science, Mechanics, Chemistry
- by Smail Benissaad
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- Engineering, Mechanics, Thermodynamics, Chemistry

The heat transfer ratio plays an important role in the industrial and engineering sectors; in this model, the authors used the hybrid nanofluid because the heat transfer ratio of the hybrid nanofluid is more than that of the base fluid. The key objective of this research work is to boost up the heat transfer ratio, for example, not only the accomplishment of energy is enough but is also expected to regulate the feeding of energy, and this is possible only to approve the development of heat transmission liquids to the mechanism of the expenditures of energy and improvement. The current research study investigates the influence of Marangoni convection, solar radiation, and viscous dissipation on the bioconvection couple stress flow of the hybrid nanofluid over a shrinking surface. This type of flow has some important application in the industrial and engineering sectors for the purpose of cooling and heating effect. To transform the non-dimensionless form of the differential equation ...

- by Ali Rehman
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- Materials Science, Mechanics, Nanofluid, Nusselt Number

The objective of this researcher paper is to study the analytical solution of unsteady hybrid nanofluid in the presences of magnetic field over a stretching surface. By using similarity transformation the major partial differential equation is converted to a set of nonlinear ordinary differential equation .the analytical method (OHAM) is used to find the approximate analytical solution of the nonlinear ordinary differential equation The BVPh 2.0 package function of MATHEMATICA is used to obtained the numerical results the result of important parameter such as, magnetic parameter, Prandtl number, Eckert number and surface convection parameter for both velocity and temperature profile are plotted and discuss. The BVPh 2.0 package is used to obtained the converges of the problem up to 25 iterations. The skin friction coefficient and Nusselt is explained in table form.

- by Ali Rehman
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- Mathematics, Materials Science, Magnetic field, Mathematical Analysis

The heat transfer ratio has an important role in industry and the engineering sector; the heat transfer ratios of CNT nanofluids are high compared to other nanofluids. This paper examines the analytical investigation of the time-dependent stagnation point flow of a CNT nanofluid over a stretching surface. For the investigation of the various physical restrictions, single and multi-walled carbon nanotubes (SWCNTs, MWCNTs) were used and compared. The defined similarity transformation was used, to reduce the given nonlinear partial differential equations (PDEs) to nonlinear ordinary differential equations (ODEs). The model nonlinear ordinary differential equations were solved, with an approximate analytical (OHAM) optimal homotopy asymptotic method being used for the model problem. The impact of different parameters such as magnetic field parameter, unsteady parameter, dimensionless nanoparticles volume friction, Prandtl number, and Eckert number are interpreted using graphs, in the fo...

- by Ali Rehman
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- Materials Science, Mechanics, Heat Transfer, Nanomaterials
- by Hussein Al-Saaidi
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- Engineering, Materials Science, Thermodynamics, Heat and Mass Transfer

This paper copes with the numerical simulation for convective heat transfer in the stator disk of an axial flux permanent magnet (AFPM) electrical machine. Overheating is one of the main issues in the design of AFMPs, which mainly occurs in the stator disk, so that it needs to be prevented. A rotor-stator configuration with 16 magnets at the periphery of the rotor is considered. Air is allowed to flow through openings in the rotor disk and channels being formed between the magnets and in the gap region between the magnets and the stator surface. The rotating channels between the magnets act as a driving force for the air flow. The significant non-dimensional parameters are the rotational Reynolds number, the gap size ratio, the magnet thickness ratio, and the magnet angle ratio. The goal is to find correlations for the Nusselt number on the stator disk according to these non-dimensional numbers. Therefore, CFD simulations have been performed with the multiple reference frame (MRF) t...

- by Alireza Rasekh
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- Engineering, Materials Science, Mechanics, Heat Transfer
- by Alireza Rasekh
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- Materials Science, Mechanics, Heat Transfer, Technology and Engineering

In this study, the numerical conjugate heat transfer and hydraulic performance of nanofluids flow in a rectangular microchannel heat sink (RMCHS) with longitudinal vortex generators (LVGs) was investigated at different Reynolds numbers (200–1200). Three-dimensional simulations are performed on a microchannel heated by a constant temperature with five different configurations with different angles of attack for the LVGs under laminar flow conditions. The study uses five different nanofluid combinations of Al2O3 or CuO, containing low volume fractions in the range of 0.5% to 3.0% with various nanoparticle sizes that are dispersed in pure water, PAO (Polyalphaolefin) or ethylene glycol. The results show that for Reynolds number ranging from 100 to 1100, Al2O3–water has the best performance compared with CuO nanofluid with Nusselt number values between 7.67 and 14.7, with an associated increase in Fanning friction factor by values of 0.0219–0.095. For the case of different base fluids, ...

- by Hussein Abbas Mohammed
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- Engineering, Materials Science, Mechanics, Thermodynamics
- by Okey Onyejekwe
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- Mathematics, Applied Mathematics, Mechanics, Heat Transfer
- by Wan Nura'in Nabilah Noranuar
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- Materials Science, Mechanics, Nanofluid, Radiative Transfer
- by Wan Nura'in Nabilah Noranuar
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- Materials Science, Mechanics, Heat Transfer, Carbon Nanotube

The study analyzed the heat transfer of water-based carbon nanotubes in non-coaxial rotation flow affected by magnetohydrodynamics and porosity. Two types of CNTs have been considered; single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). Partial differential equations are used to model the problem subjected to the initial and moving boundary conditions. Employing dimensionless variables transformed the system of equations into ordinary differential equations form. The resulting dimensionless equations are analytically solved for the closed form of temperature and velocity distributions. The obtained solutions are expressed in terms of a complementary function error. The impacts of the embedded parameters are graphically plotted in different graphs and are discussed in detail. The Nusselt number and skin friction are also evaluated. The temperature and velocity profiles have been determined to meet the initial and boundary conditions. An augment in the ...

- by Wan Nura'in Nabilah Noranuar
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- Materials Science, Mechanics, Heat Transfer, Carbon Nanotube

This study discusses the flow of hybrid nanofluid over an infinite disk in a Darcy–Forchheimer permeable medium with variable thermal conductivity and viscosity. The objective of the current theoretical investigation is to identify the thermal energy characteristics of the nanomaterial flow resulting from thermo-solutal Marangoni convection on a disc surface. By including the impacts of activation energy, heat source, thermophoretic particle deposition and microorganisms the proposed mathematical model becomes more novel. The Cattaneo-Christov mass and heat flux law is taken into account when examining the features of mass and heat transmission rather than the traditional Fourier and Fick heat and mass flux law. MoS2 and Ag nanoparticles are dispersed in the base fluid water to synthesize the hybrid nanofluid. PDEs are transformed to ODEs by using similarity transformations. The RKF-45th order shooting method is used to solve the equations. With the use of appropriate graphs, the ef...

- by Nargis Khan
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- Materials Science, Mechanics, Nanofluid, Nusselt Number

The aim of this current contribution is to examine the rheological significance of Maxwell fluid configured between two isothermal stretching disks. The energy equation is also extended by evaluating the heat source and sink features. The governing partial differential equations (PDEs) are converted into the ordinary differential equations (ODEs) by using appropriate variables. An analytically-based technique is adopted to compute the series solution of the dimensionless flow problem. The convergence of this series solution is carefully ensured. The physical interpretation of important physical parameters like the Hartmann number, Prandtl number, Archimedes number, Eckert number, heat source/sink parameter and the activation energy parameter are presented for velocity, pressure and temperature profiles. The numerical values of different involved parameters for skin friction coefficient and local Nusselt number are expressed in tabular and graphical forms. Moreover, the significance ...

- by Nargis Khan
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- Computer Science, Physics, Symmetry, PARTIAL DIFFERENTIAL EQUATION

The investigation of heat transfer analysis on steady MHD axi-symmetric flow between two infinite stretching disks in the presence of viscous dissipation and Joule heating is basic objective of this paper. Attention has been focused to acquire the similarity solutions of the equations governing the flow and thermal fields. The transformed boundary value problem is solved analytically using homotopy analysis method. The series solutions are developed and the convergence of these solutions is explicitly discussed. The analytical expressions for fluid velocity, pressure and temperature are constructed and analyzed for various set of parameter values. The numerical values for skin friction coefficient and the Nusselt number are presented in tabular form. Particular attention is given to the variations of Prandtl and Eckert numbers. We examined that the dimensionless temperature field is enhanced when we increase the values of Eckert number and Prandtl number.

- by Nargis Khan
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- Mechanics, Chemistry, Magnetohydrodynamics, Heat Transfer

Nowadays, liquid cooling channels are used for cooling of electronic equipment. These channels have to change the cross-section to pass over elements, so they undergo sudden contractions or expansions. These changes create areas that are unfavorable for heat transfer. Various methods have been proposed to improve heat transfer in these areas. In the present study, the possibility of using a nonuniform magnetic field to improve heat transfer in a millichannel including two sudden contractions has been discussed. In this study, it is assumed that a ferrofluid (EMG-805-a commercial brand) flows in the channel with a laminar regime, fully developed and steady state conditions. The walls of the channel are adiabatic, while the walls of the steps, which are in the vicinity of the electronic element, have a constant heat flux. The effects of different parameters, including locations of dipoles on the bottom and top walls, the number of dipoles, the Reynolds number, and the strength of the magnetic field on the improvement of heat transfer have been investigated. The obtained results show that the increase in Reynolds number and the strength of the magnetic field cause an increase in local Nusselt. The results show that applying a magnetic dipole on the bottom wall and just after the steps results in a significant increase in the local Nusselt number and an increase of 164.05% in the average Nusselt number compared to the case without a magnetic field.