scholarly journals The non-Newtonian maxwell nanofluid flow between two parallel rotating disks under the effects of magnetic field

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ali Ahmadian ◽  
Muhammad Bilal ◽  
Muhammad Altaf Khan ◽  
Muhammad Imran Asjad
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Brownian Motion ◽  
Flow Behavior ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Axial Direction ◽  
Rotating Disks ◽  
Physical Constraints ◽  
Fourth Order Method

Abstract The main feature of the present numerical model is to explore the behavior of Maxwell nanoliquid moving within two horizontal rotating disks. The disks are stretchable and subjected to a magnetic field in axial direction. The time dependent characteristics of thermal conductivity have been considered to scrutinize the heat transfer phenomena. The thermophoresis and Brownian motion features of nanoliquid are studied with Buongiorno model. The lower and upper disk's rotation for both the cases, same direction as well as opposite direction of rotation is investigated. The subsequent arrangement of the three dimensional Navier Stoke’s equations along with energy, mass and Maxwell equations are diminished to a dimensionless system of equations through the Von Karman’s similarity framework. The comparative numerical arrangement of modeled equations is further set up by built-in numerical scheme “boundary value solver” (Bvp4c) and Runge Kutta fourth order method (RK4). The various physical constraints, such as Prandtl number, thermal conductivity, magnetic field, thermal radiation, time relaxation, Brownian motion and thermophoresis parameters and their impact are presented and discussed briefly for velocity, temperature, concentration and magnetic strength profiles. In the present analysis, some vital characteristics such as Nusselt and Sherwood numbers are considered for physical and numerical investigation. The outcomes concluded that the disk stretching action opposing the flow behavior. With the increases of magnetic field parameter $$M$$ M the fluid velocity decreases, while improving its temperature. We show a good agreement of the present work by comparing with those published in literature.

Magneto convective flow of casson nanofluid due to Stefan blowing in the presence of bio-active mixers

2021 ◽  
pp. 239779142110166
Author(s):  
Venkatesh Puneeth ◽  
Sarpabhushana Manjunatha ◽  
Bijjanal Jayanna Gireesha ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Magnetic Field ◽  
Brownian Motion ◽  
Convective Flow ◽  
Three Dimensional ◽  
Induced Magnetic Field ◽  
Density Profiles ◽  
Casson Nanofluid ◽  
And Brownian Motion ◽  
Similarity Transformations ◽  
The Mathematical Model

The induced magnetic field for three-dimensional bio-convective flow of Casson nanofluid containing gyrotactic microorganisms along a vertical stretching sheet is investigated. The movement of these microorganisms cause bioconvection and they act as bio-active mixers that help in stabilising the nanoparticles in the suspension. The two forces, Thermophoresis and Brownian motion are incorporated in the Mathematical model along with Stefan blowing. The resulting model is transformed to ordinary differential equations using similarity transformations and are solved using [Formula: see text] method. The Velocity, Induced Magnetic field, Temperature, Concentration of Nanoparticles, and Motile density profiles are interpreted graphically. It is observed that the Casson parameter decreases the flow velocity and enhances the temperature, concentration, and motile density profiles and also it is noticed that the blowing enhances the nanofluid profiles whereas, suction diminishes the nanofluid profiles. On the other hand, it is perceived that the rate of heat conduction is enhanced with Thermophoresis and Brownian motion.

scholarly journals Significance of Nonsimilar Numerical Simulations in Forced Convection from Stretching Cylinder Subjected to External Magnetized Flow of Sisko Fluid

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jifeng Cui ◽  
Umer Farooq ◽  
Ahmed Jan ◽  
Murtada K. Elbashir ◽  
Waseem Asghar Khan ◽  
...  
Keyword(s):  
Circular Cylinder ◽  
Frictional Heating ◽  
Fluid Velocity ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Axial Direction ◽  
High Viscosity ◽  
Heat Equations ◽  
Dimensionless Numbers ◽  
Sisko Fluid

The practice of flowing effort is participating in various industries especially in nutrition productions all around the world. These fluids practices are utilized extensively in nutrition handling productions by making use of sticky liquids to produce valuable food manufactured goods in bulk. Nevertheless, such productions ought to guarantee that involved equipment such as pipelines are maintained clean as well as are cleared out for the efficient movement of fluids. The nonsimilar characteristics of involuntary convection from circular cylinder stretching in the axial direction subjected to an external flow of Sisko fluid characterized by the freely growing boundary layers (BL) are presented in this research. A circular cylinder is submerged in a stationary fluid. The axial stretching of the cylinder causes external fluid flow. The magnetic force of strength ″ B 0 ″ is enforced in the transverse direction. Because of the fluid's high viscosity, frictional heating due to viscous dissipation is quite significant. The flow is three dimensional but with no circumferential variations. The governing equations for axisymmetric flow that include the mass balance, x -momentum, and heat equation are modeled through conservation laws. The dimensionless system is developed by employing appropriate nonsimilar transformations. The numerical analyses are presented by adapting local nonsimilarity via finite-difference (FDM)-based MATLAB algorithm bvp4c. The characteristics of dimensionless numbers are determined by graphs that are plotted on momentum and heat equations. The nonsimilar simulations have been compared with the existing local similar solutions. Fluid velocity is increased as the material and curvature parameters are increased, resulting in improved heat transfer. The deviation in skin friction and local Nusselt number against the various dimensionless numbers is also analyzed.

Comparison of Two-Dimensional and Three-Dimensional Carbon Electrode Geometries Affecting Bidirectional Electroosmotic Pumping

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Matías Vázquez-Piñón ◽  
Hyundoo Hwang ◽  
Marc J. Madou ◽  
Lawrence Kulinsky ◽  
Sergio O. Martínez-Chapa
Keyword(s):  
Flow Behavior ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Electrode System ◽  
Flow Reversal ◽  
Peak Voltage ◽  
Velocity Magnitude ◽  
Electroosmotic Pumping ◽  
Coplanar Electrodes ◽  
Asymmetric Electrodes

This study compares fluid velocity magnitude and direction for three different glassy carbon (GC) electrode systems effecting alternating current (AC) electroosmotic pumping. The flow behavior is analyzed for electroosmotic pumping performed with asymmetric coplanar electrodes. Subsequently, effects of adding microposts array of two different heights (40 μm and 80 μm) are studied. Experimental results demonstrate that as peak-to-peak voltage is increased above 10 V peak-to-peak, the flow reversal is achieved for planar electrodes. Utilization of microposts-enhanced asymmetric electrodes blocks the flow reversal and alters the magnitude of the fluid velocity at the application of larger voltages (above 10 V peak-to-peak). Understanding of the consequences of three-dimensional geometry of asymmetric electrodes would allow designing the electrode system for AC electroosmotic pumping and mixing, as well as bidirectional fluid driving with equal forward and backward flow velocities.

scholarly journals An optimal analysis for Darcy–Forchheimer three-dimensional Williamson nanofluid flow over a stretching surface with convective conditions

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983351 ◽  
Author(s):  
Abdullah Dawar ◽  
Zahir Shah ◽  
Saeed Islam ◽  
Waris Khan ◽  
Muhammad Idrees
Keyword(s):  
Heat Transfer ◽  
Brownian Motion ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Flow Behavior ◽  
Three Dimensional ◽  
And Brownian Motion ◽  
Homotopy Analysis ◽  
Motion Parameters ◽  
The Impact

The augmented thermal conductivity is significant in betterment of heat transfer behavior of fluids. A number of other physical quantities such as density, viscosity, and specific heat play the key role in fluid flow behavior. Investigators have shown that the nanofluids have not only superior heat conductivity but also have better convective heat transfer capability than the base fluids. In this article, the analysis of three-dimensional Williamson fluid has been carried out under investigation. The fluid flow is taken over a linear porous stretching sheet under the influence of thermal radiation. The transformed system of equations has been solved by homotopy analysis method. The impact of embedded parameters on the fluid flow has shown graphically. The velocity profile in x-direction is decreased with the augmented stretching, Williamson, coefficient of inertia, and porosity parameters. The velocity profile in y-direction is increased with the enlarged stretching parameter, while reduced with the augmented Williamson, coefficient of inertia, and porosity parameters. The temperature profile is increased with the enlarged stretching, radiation, thermophoresis, parameter and Brownian motion parameters, and Biot number while decreased with the increased Prandtl number. The concentration profile is increased with the increased thermophoresis parameter and Biot numbers, while decreased with the enlarged stretching and Brownian motion parameters.

scholarly journals Three-dimensional heat transfer effects in external layers of a magnetized neutron star

2020 ◽  
Vol 497 (3) ◽  
pp. 2883-2892
Author(s):  
Ilya A Kondratyev ◽  
Sergey G Moiseenko ◽  
Gennady S Bisnovatyi-Kogan ◽  
Maria V Glushikhina
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Thermal Conductivity ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Three Dimensional ◽  
Light Curves ◽  
Quadrupole Component ◽  
Thermal Light ◽  
Quadrupole Magnetic Field

ABSTRACT Determination of a magnetic field structure on a neutron star (NS) surface is an important problem of a modern astrophysics. In a presence of strong magnetic fields, a thermal conductivity of a degenerate matter is anisotropic. In this paper, we present 3D anisotropic heat transfer simulations in outer layers of magnetized NSs, and construct synthetic thermal light curves. We have used a different from previous works tensorial thermal conductivity coefficient of electrons, derived from the analytical solution of the Boltzmann equation by the Chapman–Enskog method. We have obtained an NS surface temperature distribution in presence of dipole-plus-quadrupole magnetic fields. We consider a case, in which magnetic axes of a dipole and quadrupole components of the magnetic field are not aligned. To examine observational manifestations of such fields, we have generated thermal light curves for the obtained temperature distributions using a composite blackbody model. It is shown that the simplest (only zero-order spherical function in quadrupole component) non-coaxial dipole-plus-quadrupole magnetic field distribution can significantly affect the thermal light curves, making pulse profiles non-symmetric and amplifying pulsations in comparison to the pure-dipolar field.

Direct fluid–structure coupling analysis of reciprocating series seals in hydropneumatic suspension

2019 ◽  
Vol 234 (6) ◽  
pp. 932-946
Author(s):  
Shouyuan Zhang
Keyword(s):  
Friction Force ◽  
High Efficiency ◽  
Hydrodynamic Lubrication ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Axial Direction ◽  
Coupling Model ◽  
Element Discretization ◽  
Fluid Structure ◽  
Sealing Performance

The reciprocating piston seals are crucial parts in hydraulic system, which are widely used in aerospace and military industry. A direct fluid–structure coupling method with high efficiency is proposed for solving the transient Elaso-Hydrodynamic-Lubrication problem in float piston series seal system of hydropneumatic suspension. The method is validated by theory solution of a simple pad-bearing film model. Detailed three-dimensional fluid–structure coupling model of the seal system is built using finite element discretization. Rubber material tests are carried out to obtain parameters of the third-order Ogden constitutive model for the O-ring seal. The sealing performance and friction force of the complicated series seal system are analyzed with direct fluid–structure dynamic coupling simulation in high pressure and high speeds conditions. The critical speed from mixed lubrication to full film lubrication is obtained. The fluid velocity and pressure distribution in the sealing gap along axial direction is compared. The outlet volume flux leakage in different piston speeds and inlet pressures is calculated to evaluate the sealing performance. The friction force experiment for the float piston system is carried out in various speeds. The friction force from direct fluid–structure interface simulation coincides well with the test result.

Secondary Flows Associated With Slowly Oscillating and Rotating Disks

1967 ◽  
Vol 89 (2) ◽  
pp. 177-184 ◽  
Author(s):  
R. J. Hanold ◽  
J. R. Moszynski
Keyword(s):  
Reynolds Number ◽  
Secondary Flow ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Secondary Flows ◽  
Qualitative Description ◽  
Toroidal Vortex ◽  
Rotating Disks ◽  
Damping Rate

This investigation concerns the application of a flow visualization technique to obtain a quantitative and qualitative description of the secondary flow associated with a slowly oscillating disk. Included in the description is a systematic study of the flow behavior as a function of the Reynolds number. The three-dimensional character of the flow is verified and the development of a toroidal vortex both above and below the oscillating disk is illustrated. The experiments are performed in a vessel similar in design to a typical oscillating body viscometer. The effect of the Reynolds number on the damping rate of the disk is investigated. The influence of natural convective flows on the magnitude and reproducibility of the damping rate is obtained. The development of a secondary flow in the form of a toroidal vortex for both the rotating disk and rotating sphere is also illustrated.

Development of Three-Dimensional Streamline Image Velocimetry Using Superimposed Delaunay Triangulation and Geometrical Fitting

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Elishai Ezra ◽  
Eliezer Keinan ◽  
Alex Liberzon ◽  
Yaakov Nahmias
Keyword(s):  
Delaunay Triangulation ◽  
Flow Behavior ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Finite Size ◽  
Velocity Fields ◽  
Particle Tracing ◽  
Image Velocimetry ◽  
Out Of Plane ◽  
Algorithmic Approaches

Flow behavior in complex three-dimensional (3D) microscale domains is the key in the development of microcirculatory pathologies and the design of 3D microfluidics. While numerical simulations are common practice for the derivation of velocity fields in such domains, they are limited to known geometries. Current experimental methods such as micron-scale particle tracing comprise of intricate algorithmic approaches for the accurate tracing of numerous particles in a dense moving liquid suspension and are fundamentally limited in resolution to the finite size of the interrogated steps. Here, we introduce 3D streamlines image velocimetry (3D-SIV), a method to derive fluid velocity fields in arbitrary resolution for fully developed laminar flow in 3D geometries. Our approach utilizes 3D geometrical fitting and superimposed Delaunay triangulation to reconstruct streamtubes and to trace their volumetric changes. Our algorithm has applications in out-of-plane velocimetries, which we demonstrate in a 3D dilated curved geometry and in an ascending aorta. The 3D-SIV can be applied for high-resolution derivation of velocity fields in microcirculatory pathologies and to 3D microfluidic circuits, extending the potential of out-of-plane velocimetries to complex geometries and arbitrary resolution.

On the fluid behavior and stability of Ti-6Al-4V titanium alloy GMAW molten pool: Effect of the longitudinal magnetic field

2021 ◽  
pp. 2150283
Author(s):  
Chenglong Wu ◽  
Shaohua Han ◽  
Dingqi Xue ◽  
Jianbin Zhan
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Molten Pool ◽  
Longitudinal Magnetic Field ◽  
Liquid Metals ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Surface Profile ◽  
Length Change ◽  
The Magnetic Field

By establishing a three-dimensional (3D) numerical simulation of the Ti-6Al-4V Gas Metal Argon Welding (GMAW) molten pool, the molten pool’s heat transfer and fluid flow behavior under a longitudinal magnetic field were investigated. The simulation results show that when the droplet enters the molten pool, the liquid metals on the molten pool’s surface symmetrically flow towards both sides of the molten pool from different angles. With the increase of the magnetic field strengthens, the temperature gradually decreases, and the fluid flow velocity increases continuously. Besides, the magnetic field strength is correlated positively with the molten pool’s size with a certain range of 0–0.03 T. However, when the magnetic field strengthens reach 0.04 T, the magnetic field is correlated negatively with the molten pool’s size. Because the Marangoni and buoyancy begin to weaken, the molten pool’s length change occurs before the width change. Simultaneously, a sizeable velocity region appears on the left side of the molten pool. Thus, the liquid metal gathers on the left side, resulting in the weld cross-section’s asymmetry. It can conclude that only when the magnetic strengthen keeps in the range of 0–0.03 T, the longitudinal magnetic field can make the molten pool’s surface profile smooth.

scholarly journals Magnetohydrodynamic Jeffrey nanoliquid flow with thermally radiative Newtonian heat and mass species

2018 ◽  
Vol 64 (6) ◽  
pp. 628 ◽  
Author(s):  
Sabir Ali Shehzad
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Liquid Flow ◽  
Three Dimensional ◽  
Numerical Data ◽  
Heat Absorption ◽  
Nanoparticle Concentration ◽  
Physical Constraints ◽  
Electrically Conducting ◽  
Mathematical Expressions

This study characterizes the properties of Newtonian heat and mass species conditions in three-dimensional Jeffrey nanoliquid flow generated by the movement of thermally radiative surface. The liquid flow is electrically conducting through the consideration of magnetic field. The aspects of heat absorption, generation and thermal radiation are considered in the equation of energy conservation. The boundary layer phenomenon is employed to obtain the mathematical expressions of considered physical model. These equations are solved via homotopic scheme. The convergence of homotopic solutions is validated by the numerical data. The importance of physical constraints on temperature and nanoparticle concentration of liquid is visualized by the graphical results.

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