Rotating Al2O3-H2O nanofluid flow and heat transfer with internal heating, velocity slip and different shapes of nanoparticles

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saeed Dinarvand ◽  
Mohammadreza Nademi Rostami
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Phase Analysis ◽  
Base Fluid ◽  
Velocity Slip ◽  
Analysis Method ◽  
Internal Heating ◽  
Two Phase ◽  
Content Type ◽  
Flow And Heat Transfer

PurposeThis research numerically investigates the steady laminar 3D forced convective flow and heat transfer of a rotating Al2O3/water nanofluid past a linearly stretching sheet with the help of a novel two-phase analysis method by considering different nanoparticle shapes as well as velocity slip boundary condition plus internal heating.Design/methodology/approachThe authors’ novel two-phase analysis method implements the Jang and Choi model for the effective thermal conductivity and incorporates it with Tiwari–Das mathematical model. Besides, the shape factors of the nanoparticles have also taken into account using the Timofeeva model for effective dynamic viscosity. The Prandtl number of the base fluid is kept constant at 6.2 and the temperature of the nanoparticles as well as the base fluid molecules is assumed to be 300 K. In short, after using the similarity transformation method, the obtained dimensionless nonlinear ODEs are numerically solved using the bvp4c built-in function from MATLAB. The governing parameters are solid volume concentration, rotation parameter, velocity slip parameter, heat generation or absorption parameter and Prandtl number of the base fluid.FindingsIt is argued that when the cylindrical shape for alumina is chosen, the maximum values for skin friction coefficients and local Nusselt number have been obtained among the other shapes. Further, the velocity slip enhancement in this problem will lead to a drastic reduction in the foregoing quantities of engineering interest.Originality/valueTo the best of the authors’ knowledge, this research is a novel attitude to two-phase nanofluid model.

scholarly journals Falkner-Skan Flow of a Maxwell Fluid with Heat Transfer and Magnetic Field

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. Qasim ◽  
S. Noreen
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Prandtl Number ◽  
Comparative Study ◽  
Homotopy Analysis Method ◽  
Maxwell Fluid ◽  
Deborah Number ◽  
Analysis Method ◽  
Flow And Heat Transfer ◽  
Homotopy Analysis

This investigation deals with the Falkner-Skan flow of a Maxwell fluid in the presence of nonuniform applied magnetic fi…eld with heat transfer. Governing problems of flow and heat transfer are solved analytically by employing the homotopy analysis method (HAM). Effects of the involved parameters, namely, the Deborah number, Hartman number, and the Prandtl number, are examined carefully. A comparative study is made with the known numerical solution in a limiting sense and an excellent agreement is noted.

Flow and Heat Transfer of Nanofluids Over a Rotating Porous Disk with Velocity Slip and Temperature Jump

2015 ◽  
Vol 70 (5) ◽  
pp. 351-358 ◽  
Author(s):  
Chenguang Yin ◽  
Liancun Zheng ◽  
Chaoli Zhang ◽  
Xinxin Zhang
Keyword(s):  
Heat Transfer ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Temperature Fields ◽  
Analysis Method ◽  
Governing Equations ◽  
Porous Disk ◽  
Flow And Heat Transfer ◽  
Homotopy Analysis ◽  
Good Agreement

AbstractIn this article, we discuss the flow and heat transfer of nanofluids over a rotating porous disk with velocity slip and temperature jump. Three types of nanoparticles – Cu, Al2O3, and CuO – are considered with water as the base fluid. The nonlinear governing equations are reduced into ordinary differential equations by Von Karman transformations and solved using homotopy analysis method (HAM), which is verified in good agreement with numerical ones. The effects of involved parameters such as porous parameter, velocity slip, temperature jump, as well as the types of nanofluids on velocity and temperature fields are presented graphically and analysed.

Two-Phase Study of Fluid Flow and Heat Transfer in Gas-Solid Flows (Nanofluids)

2011 ◽  
Vol 110-116 ◽  
pp. 3878-3882 ◽  
Author(s):  
Hossein Afshar ◽  
Mehrzad Shams ◽  
Seyed Mojtba Mousavi Nainian ◽  
Goodarz Ahmadi
Keyword(s):  
Heat Transfer ◽  
Transfer Rate ◽  
Base Fluid ◽  
Volume Fraction ◽  
Maxwell Model ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Gravity Forces ◽  
Phase Study ◽  
Two Phase Heat Transfer

In this paper, two phase heat transfer of a mixture of nanopaticles in air flow as a type of nanofluid is studied. Volume fraction of the dispersed phase is very low (less than 1%). Nanoparticles travel in the base fluid due to drag, brownian and gravity forces and are tracked according to lagrangian approach. Effect of reduced specific heat of nanofluid on heat transfer is considered. The results show an increase in heat transfer rate which is very much more than that predicted by the Maxwell model.

Boundary layer flow and heat transfer of a non-Newtonian nanofluid over a non-linearly stretching sheet

2016 ◽  
Vol 26 (7) ◽  
pp. 2198-2217 ◽  
Author(s):  
Macha Madhu ◽  
Naikoti Kishan ◽  
A. Chamkha
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Sherwood Number ◽  
Stretching Sheet ◽  
Lewis Number ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Layer Flow ◽  
Local Sherwood Number

Purpose The purpose of this paper is to study the boundary layer flow and heat transfer of a power-law non-Newtonian nanofluid over a non-linearly stretching sheet. Design/methodology/approach The governing equations describing the problem are transformed into a nonlinear ordinary differential equations by suitable similarity transformations. The resulting equations for this investigation are solved numerically by using the variational finite element method. Findings It was found that the local Nusselt number increases by increasing the Prandtl number, stretching sheet parameter and decreases by increasing the power-law index, thermophoresis parameter and Lewis number. Increases in the stretching sheet parameter, Prandtl number and thermophoresis parameter decrease the local Sherwood number values. The effects of Brownian motion and Lewis number lead to increases in the local Sherwood number values. Originality/value The work is relatively original as very little work has been reported on non-Newtonian nanofluids.

Fluid flow and heat transfer for a particle-laden gas modeled as a two-phase turbulent flow

2018 ◽  
Vol 28 (8) ◽  
pp. 1866-1891 ◽  
Author(s):  
John Gorman ◽  
Eph Sparrow
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Turbulent Flow ◽  
Particle Interactions ◽  
Two Phase ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Impingement Plate ◽  
Axis Switching ◽  
Jet Axis

Purpose The purpose of this study is to examine the physical processes experienced by a particle-laden gas due to various types of collisions, different heat transfer modalities and jet axis switching. Here, attention is focused on a particle-laden gas subjected to jet axis switching while experiencing fluid flow and heat transfer. Design/methodology/approach The methodology used to model and solve these complex problems is numerical simulation treated here as a two-phase turbulent flow in which the gas and the particles keep their separate identities. For the turbulent flow model, validation was achieved by comparisons with appropriate experimental data. The considered interactions between the fluid and the particles include one-way fluid–particle interactions, two-way fluid–particle interactions and particle–particle interactions. Findings For the fluid flow portion of the work, emphasis was placed on the particle collection efficiency and on independent variables that affect this quantity and the trajectories of the fluid and of the particles as they traverse the space between the jet orifice and the impingement plate. The extent of the effect depended on four factors: particle size, particle density, number of particles and the velocity of the fluid flow. The major effect on the heat transferred to the impingement plate occurred when direct heat transfer between the impinging particles and the plate was taken into account. Originality/value This paper deals with issues never before dealt with in the published literature: the effect of jet axis switching on the fluid mechanics of gas-particle flows without heat transfer and the effect of jet axis switching and the presence of particles on jet impingement heat transfer. The overall focus of the work is on the impact of jet axis switching on particle-laden fluid flow and heat transfer.

Nanotechnology as Effective Passive Technique for Heat Transfer Augmentation

2018 ◽  
pp. 1-49
Keyword(s):  
Heat Transfer ◽  
Base Fluid ◽  
Single Phase ◽  
Particle Dispersion ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Fluid Properties ◽  
And Behaviors ◽  
Passive Technique ◽  
Definition Of

Nanofluids are fluids containing the solid nanometer-sized particle dispersion. Two main methods are introduced in this chapter, namely single-phase and two-phase modeling. In first method, the combination of nanoparticle and base fluid is considered as a single-phase mixture with steady properties, and in the second method, the nanoparticle properties and behaviors are considered separately from the base fluid properties and behaviors. Moreover, nanofluid flow and heat transfer can be studied in the presence of thermal radiation, electric field, magnetic field, and porous media. In this chapter, a definition of nanofluid and its applications have been presented.

Scrutiny of Unsteady Flow and Heat Transfer in a Backward-Facing Step Under Pulsating Nanofluid Blowing Using the Eulerian-Eulerian Approach

2017 ◽  
Vol 35 (1) ◽  
pp. 93-105 ◽  
Author(s):  
I. Zahmatkesh ◽  
E. Torshizi
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Unsteady Flow ◽  
Water Flow ◽  
Base Fluid ◽  
Phase Model ◽  
Backward Facing Step ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Non Equilibrium

AbstractIn this paper, unsteady flow and heat transfer of water flow in a backward-facing step under pulsating nanofluid blowing are studied numerically. Attention is focused to examine the impact of this type of blowing and its pertinent parameters on the heat transfer performance and to detect possible non-equilibrium between the base fluid and the nanoparticles inside the flow field. To this aim, the Eulerian-Eulerian two-phase model is adopted. This approach consists of separate equation sets for the base fluid and the nanoparticles. So, it provides details of the flow field for each of the constituents, separately. Computations are undertaken for different cases and the consequences of the frequency, amplitude, and the mean velocity of the pulsating blowing as well as the type, diameter, and the volume fraction of the nanoparticles therein on the heat transfer characteristics are analyzed. It is found that in addition to thermal conductivity of the blown nanoparticles, their penetration into the water flow is an important trait that has a momentous role on the heat transfer rate. In the current Eulerian-Eulerian simulation, temperature distributions of the base fluid and the nanoparticles are similar but the corresponding velocity fields are quite distinct. This reveals a kind of non-equilibrium between the base fluid and the nanoparticles inside the flow that invalidates equilibrium approaches (e.g., the single-phase model or the two-phase mixture model) for the description of the problem.

Effects of moving wall on the flow of micropolar fluid inside a right angle triangular cavity

2018 ◽  
Vol 28 (10) ◽  
pp. 2404-2422 ◽  
Author(s):  
Mubbashar Nazeer ◽  
N. Ali ◽  
T. Javed
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Prandtl Number ◽  
Micropolar Fluid ◽  
Richardson Number ◽  
Average Nusselt Number ◽  
Content Type ◽  
Moving Wall ◽  
Flow And Heat Transfer

Purpose The main purpose of this study is to examine the effects of moving wall on the mixed convection flow and heat transfer in a right-angle triangular cavity filled with a micropolar fluid. Design/methodology/approach It is assumed that the bottom wall is uniformly heated and the right inclined wall is cold, whereas the vertical wall is adiabatic and moving with upward/downward velocity v0/−v0, respectively. The micropolar fluid is considered to satisfy the Boussinesq approximation. The governing equations and boundary conditions are solved using the Galerkin finite element method. The Penalty method is used to eliminate the pressure term from the momentum equations. To accomplish the consistent solution, the value of the penalty parameter is taken 107. The simulations are performed for a wide range of Richardson number, micropolar parameter, Prandtl number and Reynolds number. Findings The results are presented in the form of streamlines, isotherms and variations of average Nusselt number and fluid flow rate depending on the Richardson number, Prandtl number, micropolar parameter and direction of the moving wall. The flow field and temperature distribution in the cavity are affected by these parameters. An average Nusselt number into the cavity in both cases increase with increasing Prandtl and Richardson numbers and decreases with increasing micropolar parameter, and it has a maximum value when the lid is moving in the downward direction for all the physical parameters. Research limitations/implications The present investigation is conducted for the steady, two-dimensional mixed convective flow in a right-angle triangular cavity filled with micropolar fluid. An extension of the present study with the effects of cavity inclination, square cavity, rectangular, trapezoidal and wavy cavity will be the interest of future work. Originality/value This work studies the effects of moving wall, micropolar parameter, Richardson number, Prandtl number and Reynolds number parameter in a right-angle triangular cavity filled with a micropolar fluid on the fluid flow and heat transfer. This study might be useful to flows of biological fluids in thin vessels, polymeric suspensions, liquid crystals, slurries, colloidal suspensions, exotic lubricants, solar engineering for construction of triangular solar collector, construction of thermal insulation structure and geophysical fluid mechanics, etc.

Stagnation-point flow of an aqueous titania-copper hybrid nanofluid toward a wavy cylinder

2018 ◽  
Vol 28 (7) ◽  
pp. 1716-1735 ◽  
Author(s):  
Mohammad Yousefi ◽  
Saeed Dinarvand ◽  
Mohammad Eftekhari Yazdi ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Stagnation Point ◽  
Base Fluid ◽  
Stagnation Point Flow ◽  
Hybrid Nanofluid ◽  
Content Type ◽  
Analytic Modeling ◽  
Flow And Heat Transfer ◽  
Special Cases ◽  
Hybrid Nanofluids

Purpose The purpose of this paper is to investigate analytically the steady general three-dimensional stagnation-point flow of an aqueous titania-copper hybrid nanofluid past a circular cylinder that has a sinusoidal radius variation. Design/methodology/approach First, the analytic modeling of hybrid nanofluid is presented, and using appropriate similarity variables, the governing equations are transformed into nonlinear ordinary differential equations in the dimensionless stream function, which is solved by the well-known function bvp4c from MATLAB. Findings The current solution demonstrates good agreement with those of the previously published studies in the special cases of regular fluid and nanofluids. Graphical results are presented to investigate the influences of the titania and copper nanoparticle volume fractions and also the nodal/saddle indicative parameter on flow and heat transfer characteristics. Here, the thermal characteristics of hybrid nanofluid are found to be higher in comparison to the base fluid and fluid containing single nanoparticles. An important point to note is that the developed model can be used with great confidence to study the flow and heat transfer of hybrid nanofluids. Originality/value Analytic modeling of hybrid nanofluid is the important originality of present study. Hybrid nanofluids are potential fluids that offer better heat transfer performance and thermophysical properties than convectional heat transfer fluids (oil, water and ethylene glycol) and nanofluids with single nanoparticles. In this investigation, titania (TiO2, 50 nm), copper (Cu, 20 nm) and the hybrid of these two are separately dispersed into the water as the base fluid and analyzed.

Natural convection in a triangular cavity filled with a micropolar fluid

2017 ◽  
Vol 27 (2) ◽  
pp. 504-515 ◽  
Author(s):  
Mikhail Sheremet ◽  
Teodor Grosan ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Prandtl Number ◽  
Micropolar Fluid ◽  
Content Type ◽  
Viscosity Parameter ◽  
Flow And Heat Transfer ◽  
Wide Range

Purpose The purpose of this paper is to study steady natural convection flow and heat transfer in a triangular cavity filled with a micropolar fluid. Design/methodology/approach It is assumed that the left inclined wall is heated, whereas the other walls are cooled and maintained at constant temperatures. All four walls of the cavity are assumed to be rigid and impermeable. The micropolar fluid is considered to satisfy the Boussinesq approximation. The governing equations and boundary conditions are solved using the finite difference method of the second order accuracy over a wide range of the Rayleigh number, Prandtl number, vortex viscosity parameter and two values of micro-gyration parameter, namely, strong concentration (n = 0) and week concentration (n = 0.5). Findings The results are presented in the form of streamlines, isotherms, vorticity contours and variations of average Nusselt number and fluid flow rate depending on the Rayleigh number, Prandtl number, vortex viscosity parameter and micro-gyration parameter. The flow field and temperature distribution in the cavity are affected by these parameters. The heat transfer rate into the cavity is decreasing upon the raise of the vortex viscosity parameter. Originality/value This work studies the effects of vortex viscosity parameter and micro-gyration parameter in a triangular cavity filled with a micropolar fluid on the fluid flow and heat transfer. This study might be useful to flows of biological fluids in thin vessels, polymeric suspensions, liquid crystals, slurries, colloidal suspensions, exotic lubricants; for the design of solar collectors, room ventilation systems and electronic cooling systems; and so on.

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