scholarly journals Hall and ion-slip effects on MHD fluid flow in a rotating curved duct with aspect ratio 3

AIP Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 015302
Author(s):  
Md. Rafiqul Islam ◽  
Md. Abdus Samad ◽  
Md. Mahmud Alam
Keyword(s):  
Fluid Flow ◽  
Aspect Ratio ◽  
Curved Duct ◽  
Slip Effects ◽  
Ion Slip

scholarly journals A computational modeling on transient heat and fluid flow through a curved duct of large aspect ratio with centrifugal instability

2021 ◽  
Vol 136 (4) ◽  
Author(s):  
Shamsun Naher Dolon ◽  
Mohammad Sanjeed Hasan ◽  
Giulio Lorenzini ◽  
Rabindra Nath Mondal
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Aspect Ratio ◽  
Computational Modeling ◽  
Flow Velocity ◽  
Numerical Technique ◽  
Large Aspect Ratio ◽  
Duct Flow ◽  
Curved Duct ◽  
Centrifugal Instability

AbstractDue to remarkable applications of the curved ducts in engineering fields, scientists have paid much attention to invent new characteristics of curved-duct flow in mechanical systems. In the ongoing study, a computational modeling of fluid flow and energy distribution through a curved rectangular duct of large aspect ratio is presented. Governing equations are enumerated by using a spectral-based numerical technique together with the function expansion and collocation method. The main purpose of the paper is to analyze the effect of centrifugal force in the flow transition as well as heat transfer in the fluid. The investigations are performed for the aspect ratio, Ar = 4; the curvature ratio, $$\delta = 0.5$$ δ = 0.5 ; the Grashof number, $${\text{Gr}} = 1000$$ Gr = 1000 ; and varying the Dean number, $$0 < {\text{Dn}} \le 1000.$$ 0 < Dn ≤ 1000 . It is found that various types of flow regimes including steady-state and irregular oscillations occur as Dn is increased. To well understand the characteristics of the flow phase spaces and power spectrum of the solutions are performed. Next, pattern variations of axial and secondary flow velocity with isotherms are illustrated for different Dn’s. It is revealed that the flow velocity and the isotherms are significantly influenced by the duct curvature and the aspect ratio. Convective heat transfer and temperature gradients are calculated which explores that the fluids are diversified due to centrifugal instability, and as a consequence the overall heat transfer is enhanced significantly in the curved duct.

scholarly journals Hall and ion-slip effects on unsteady MHD Bingham fluid flow with suction

2018 ◽  
Vol 87 (4) ◽  
pp. 221-229 ◽  
Author(s):  
Md. Mollah ◽  
Muhammad Islam ◽  
Md Alam
Keyword(s):  
Fluid Flow ◽  
Bingham Fluid ◽  
Slip Effects ◽  
Ion Slip

scholarly journals Couple Stresses and Thermophoresis Influences on Free Convective Heat and Mass Transfer of Viscoelastic Fluid with Hall and Ion-Slip Effects.

2020 ◽  
Vol 17 ◽  
pp. 117-132
Author(s):  
Gamil Shalaby
Keyword(s):  
Mass Transfer ◽  
Nusselt Number ◽  
Fluid Flow ◽  
Couple Stress ◽  
Vertical Channel ◽  
Second Grade ◽  
Physical Parameters ◽  
Slip Effects ◽  
Hall Parameter ◽  
Ion Slip

 An analysis is presented to investigate the Hall and Ion-slip effects on non-Newtonian couple stress fluid flow between vertical channel in the presence of thermophoresis phenomena. The considered fluid obeys to the viscoelastic second-grade model. The problem is modulated mathematically to describe continuity, momentum, temperature, and concentration equations. The influences of physical parameters of dimensionless equations of velocity components () and (), temperature () and concentration () have been shown in some of figuthe res, as well as skin friction (), Nusselt number() and Sherwood number() have been computed. It is found that the velocity  decreases with increasing in Hall parameter and Ion slip parameters.

Laminar Forced Convection in Annular Microchannels With Slip Flow Regime

2009 ◽  
Author(s):  
Arman Sadeghi ◽  
Abolhassan Asgarshamsi ◽  
Mohammad Hassan Saidi
Keyword(s):  
Nusselt Number ◽  
Fluid Flow ◽  
Aspect Ratio ◽  
Boundary Conditions ◽  
Knudsen Number ◽  
Gas Flow ◽  
Slip Flow ◽  
Outer Wall ◽  
Graphical Form ◽  
Uniform Temperature

Fluid flow and heat transfer at microscale have attracted an important research interest in recent years due to the rapid development of microelectromechanical systems (MEMS). Fluid flow in microdevices has some characteristics which one of them is rarefaction effect related with gas flow. In this research, hydrodynamically and thermally fully developed laminar rarefied gas flow in annular microducts is studied using slip flow boundary conditions. Two different cases of the thermal boundary conditions are considered, namely: uniform temperature at the outer wall and adiabatic inner wall (Case A) and uniform temperature at the inner wall and adiabatic outer wall (Case B). Using the previously obtained velocity distribution, energy conservation equation subjected to relevant boundary conditions is numerically solved using fourth order Runge-Kutta method. The Nusselt number values are presented in graphical form as well as tabular form. It is realized that for the case A increasing aspect ratio results in increasing the Nusselt number, while the opposite is true for the case B. The effect of aspect ratio on Nusselt number is more notable at smaller values of Knudsen number, while its effect becomes slighter at large Knudsen numbers. Also increasing Knudsen number leads to smaller values of Nusselt number for the both cases.

Unsteady MHD Natural Convective Flow of a Rotating Fluid over an Infinite Vertical Plate due to Oscillatory Movement of the Free-Stream with Hall and Ion-Slip Currents

2017 ◽  
Vol 11 ◽  
pp. 146-161 ◽  
Author(s):  
Jitendra Kumar Singh ◽  
Gauri Shenkar Seth ◽  
S. Ghousia Begum
Keyword(s):  
Fluid Flow ◽  
Convective Flow ◽  
Vertical Plate ◽  
Free Stream ◽  
Flow Direction ◽  
Rotating Fluid ◽  
Oscillatory Movement ◽  
Buoyancy Forces ◽  
Ion Slip ◽  
Infinite Vertical Plate

In the present research study a mathematical analysis has been presented for unsteady MHD natural convective flow of a rotating fluid over an infinite vertical plate immersed in a fluid saturated porous medium with oscillating free-stream. The effects of Hall and ion-slip currents also considered on the fluid flow. The unsteady MHD flow over the vertical plate is induced due to thermal and concentration buoyancy forces and oscillatory movement of the free-stream. The partial differential equations governing the motion for the fluid flow are solved analytically. The effects of various pertinent flow parameters on the fluid velocity, fluid temperature and species concentration are presented in graphical form whereas that on skin friction and rate of heat and mass transfer at the plate are presented in tabular form. An interesting observation recorded from the present analysis that there appears reversal flow in the secondary flow direction due to presence of thermal and/or concentration buoyancy forces. However, in the absence of both reversals flow does not exist in the secondary flow direction. It is also noted that the thickness of momentum boundary layer decreases with rise in frequency of oscillations of the free-stream.

The Effects of Hall and Ion Slip on the Electrical Conductivity of Partially Ionized Gases for Magnetohydrodynamic Re-Entry Vehicle Application

1962 ◽  
Vol 84 (2) ◽  
pp. 177-184 ◽  
Author(s):  
M. J. Brunner
Keyword(s):  
Electrical Conductivity ◽  
Cross Sections ◽  
Effective Conductivity ◽  
Ionized Gas ◽  
Equilibrium Conditions ◽  
Degree Of Ionization ◽  
Slip Effects ◽  
Wide Range ◽  
Ion Slip ◽  
Partially Ionized

The presence of a partially ionized gas around a hypersonic vehicle permits the application of magnetohydrodynamic (MHD) devices during re-entry. The operation of such MHD devices on a re-entry vehicle will largely depend on the magnitude of the electrical conductivity of the gas between the electrodes. In some cases it may be necessary to seed the air in order to insure high conductivity. The operation of the re-entry vehicle at relatively low gas densities and high magnetic fields will produce Hall and ion slip effects which may materially reduce the effective conductivity between the electrodes. The electrical conductivity including Hall and ion slip effects for air is presented for a wide range of pressures and temperatures and for a typical re-entry vehicle, with and without seeding. The electrical conductivity is evaluated for equilibrium conditions considering the number density and collision cross sections for electrons, neutrals, and ions. The Hall and ion slip effects are evaluated from the degree of ionization, the cyclotron frequency, and the time between collisions for electrons, neutrals, and ions.

scholarly journals Numerical Study of MHD Flow and Heat Transfer Through Porous Medium Between Two Parallel Plates With Hall and Ion Slip Effects

2020 ◽  
Vol 7 ◽  
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Numerical Study ◽  
Mhd Flow ◽  
Parallel Plates ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
Slip Effects ◽  
Ion Slip ◽  
Temperature And Pressure

This paper studies the effects of Hall and ion slip on two dimensional incompressible flow and heat transfer of an electrically conducting viscous fluid in a porous medium between two parallel plates, generated due to periodic suction and injection at the plates. The flow field, temperature and pressure are assumed to be periodic functions in ti e ω and the plates are kept at different but constant temperatures. A numerical solution for the governing nonlinear ordinary differential equations is obtained using quasilinearization method. The graphs for velocity, temperature distribution and skin friction are presented for different values of the fluid and geometric parameters.

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