Wyniki wyszukiwania - BazTech

1

Pulsatile MHD flow of two immiscible nanofluids through a porous channel with slip effects

Medisetty Padma Devi, Suripeddi Srinivas, Badeti Satyanarayana, Kuppalapalle Vajravelu

International Journal of Applied Mechanics and Engineering

|

2024

|

Vol. 29, no. 1

105--129

EN

The present study is carried out to investigate the effects of shape factor nanoparticles on the oscillatory MHD flow of a nanofluid in two immiscible liquids in a horizontal porous channel with velocity and thermal slip on the walls. Thermal radiation, Joule heating, viscous and Darcy dissipations have been accounted for in the model. We have considered and as nanoparticles, in the lower region (Region-I) and upper region (Region-II) respectively, with water as a base fluid. The effective ratio of thermal conductivity of the nanofluid is evaluated using the Maxwell-Garnetts model. Graphical behavior of velocity, temperature, and rate of heat transfer distributions have been depicted for the cases of slip and no-slip effects. This study has been made to understand the impact of different nanoparticle shape factors on temperature and heat transfer rate. For various parameters, values of shear stress distribution at the walls and the mass flux are shown in tabular form. Our study asserts that with the increase of the strength of the magnetic field, the velocity of the liquid falls and enhances the temperature of the liquid. The influence of different combinations of nanoparticles, on the flow variables, have also been discussed. In order to validate the analytical results, the numerical evaluation of the closed-form results, for the velocity distribution, has been compared with those of the numerical method, by using the NDSolve command in MATHEMATICA, and a good agreement is observed.

2

Numerical solution of MHD channel flow in a porous medium with uniform suction and injection in the presence of an inclined magnetic field

Chutia Muhim

Journal of Applied Mathematics and Computational Mechanics

|

2022

|

Vol. 21, nr 2

5--13

EN

In this paper, the steady fully developed MHD flow of a viscous incompressible electrically conducting fluid through a channel filled with a porous medium and bounded by two infinite walls is investigated numerically for the cases (i) Poiseuille flow and (ii) Couette-Poiseuille flow; with uniform suction and injection at the walls in the presence of an inclined magnetic field. The Brinkman equation is used for the flow in the porous channel and solved numerically using the finite difference method. Numerical results are obtained for velocity. The effects of various dimensionless parameters such as Hartmann number (M), suction/injection parameter (S), permeability parameter (α) and angle of inclination (θ) on the flow are discussed and presented graphically.

3

A numerical examination of an unsteady nonlinear MHD flow in the presence of thermal radiation and heat generation

Agbaje T. M., Leach P. G. L.

International Journal of Applied Mechanics and Engineering

|

2021

|

Vol. 26, no. 1

1--17

EN

In this study, the spectral perturbation method and the spectral relaxation method are used to solve the nonlinear differential equations of an unsteady nonlinear MHD flow in the presence of thermal radiation and heat generation. The SPM is mainly based on series expansion, generating series approximation coupled with the Chebyshev spectral method. The numerical results generated using the spectral perturbation method were compared with those found in the literature, and the two results were in good agreement.

4

Transient heat and mass transfer of hydromagnetic effects on the flow past a porous medium with movable vertical permeablesheet

Okedoye A. M., Salawu S. O.

International Journal of Applied Mechanics and Engineering

|

2020

|

Vol. 25, no. 4

175--190

EN

An unsteady flow of heat and species transport through a porous medium in an infinite movable vertical permeable flat surface is considered. The hydromagnetic chemical reactive fluid flow is stimulated by the thermal and solutant convection, and propelled by the movement of the surface. The formulated nonlinear flow equations in time space are solved analytically by asymptotic expansions to obtain solutions for the flow momentum, energy and chemical concentration for various thermo-physical parameters. The existence of flow characteristic is defined with the assistance of the flow parameters. In the study, the impact of some pertinent flow terms is reported and discussed. The study revealed that the species boundary layer increases with a generative chemical reaction and decreases with a destructive chemical reaction. Also, arise in the generative species reaction term reduces the flow momentum for the cooling surface. The impact of other flow governing parameters is displayed graphically as well as the fluid wall friction, wall energy and species gradients. The results of this study are important in chemical thermal engineering for monitoring processes to avoid solution blow up.

5

Perturbation solutions for magnetohydrodynamics (MHD) flow of in a non-Newtonian fluid between concentric cylinders

Yurusoy M., Guler O. F.

International Journal of Applied Mechanics and Engineering

|

2019

|

Vol. 24, no. 1

199--211

EN

The steady-state magnetohydrodynamics (MHD) flow of a third-grade fluid with a variable viscosity parameter between concentric cylinders (annular pipe) with heat transfer is examined. The temperature of annular pipes is assumed to be higher than the temperature of the fluid. Three types of viscosity models were used, i.e., the constant viscosity model, space dependent viscosity model and the Reynolds viscosity model which is dependent on temperature in an exponential manner. Approximate analytical solutions are presented by using the perturbation technique. The variation of velocity and temperature profile in the fluid is analytically calculated. In addition, equations of motion are solved numerically. The numerical solutions obtained are compared with analytical solutions. Thus, the validity intervals of the analytical solutions are determined.

6

Effect of thermal radiation, chemical reaction and viscous dissipation on MHD flow

Zigta B.

International Journal of Applied Mechanics and Engineering

|

2018

|

Vol. 23, no. 3

787--801

EN

This study examines the effect of thermal radiation, chemical reaction and viscous dissipation on a magnetohydro- dynamic flow in between a pair of infinite vertical Couette channel walls. The momentum equation accounts the effects of both the thermal and the concentration buoyancy forces of the flow. The energy equation addresses the effects of the thermal radiation and viscous dissipation of the flow. Also, the concentration equation includes the effects of molecular diffusivity and chemical reaction parameters. The gray colored fluid considered in this study is a non-scattering medium and has the property of absorbing and emitting radiation. The Roseland approximation is used to describe the radiative heat flux in the energy equation. The velocity of flow transforms kinetic energy into heat energy. The increment of the velocity due to internal energy results in heating up of the fluid and consequently it causes increment of the thermal buoyancy force. The Eckert number being the ratio of the kinetic energy of the flow to the temperature difference of the channel walls is directly proportional to the thermal energy dissipation. It can be observed that increasing the Eckert number results in increasing velocity. A uniform magnetic field is applied perpendicular to the channel walls. The temperature of the moving wall is high enough due to the presence of thermal radiation. The solution of the governing equations is obtained using regular perturbation techniques. These techniques help to convert partial differential equations to a set of ordinary differential equations in dimensionless form and thus they are solved analytically. The following results are obtained: from the simulation study it is observed that the flow pattern of the fluid is affected due to the influence of the thermal radiation, the chemical reaction and viscous dissipation. The increment in the Hartmann number results in the increment of the Lorentz force but a decrement in velocity of the flow. An increment in the radiative parameter results in a decrement in temperature. An increment in the Prandtl number results in a decrement in thermal diffusivity. An increment in both the chemical reaction parameter and molecular diffusivity results in a decrement in concentration.

7

Influence of convective heat and mass conditions in MHD flow of nanofluid

Shehzad S. A., Hayat T., Alsaedi A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2015

|

Vol. 63, nr 2

465--474

EN

This article aims to investigate the two-dimensional magnetohydrodynamic (MHD) boundary layer flow of nanofluid. Convective mass condition is introduced. Analysis has been discussed in the presence of an applied magnetic field. The Brownian motion and thermophoresis effects are incorporated. The arising nonlinear problems are first converted to ordinary differential equations and then series solutions are constructed. Convergence of series solutions is examined through plots and numerical values. Results are plotted and discussed for the temperature and concentration. Numerical computations for skin-friction coefficient, local Nusselt and Sherwood numbers are performed and analyzed. Comparison with the previous limiting case is noted in an excellent agreement.

8

Transient free convection MHD flow through a porous medium between two vertical plates

Kalita B., Borkakati A. K.

International Journal of Applied Mechanics and Engineering

|

2005

|

Vol. 10, no 1

87-94

EN

An analysis is presented to investigate the flow and heat transfer characteristic of a viscous incompressible and electrically conducting fluid through a porous medium bounded by two long vertical parallel plates in the presence of a uniform magnetic field applied transversely to the flow. The governing momentum and energy equations are solved by the Laplace transform technique and the solutions are presented for velocity and temperature distributions and shear stress. The effects of the four parameters, namely, the Darcy number, viscosity ratio parameter, magnetic Hartmann number, and Prandtl number on temperature and velocity distributions are shown in graphs and presented through the results and discussion. Also, the effects of these four parameters on skin friction are given.

9

Boundary layer MHD flow of a viscoelastic fluid over a porous quadratic stretching sheet

Khan S. K.

International Journal of Applied Mechanics and Engineering

|

2005

|

Vol. 10, no 2

267-279

EN

A mathematical analysis on the boundary layer MHD flow of a viscoelastic fluid over a porous stretching sheet has been presented in this paper. A typical choice of quadratic stretching of the boundary, which generates a quadratic part in velocity parallel to the boundary sheet and a linear mass flux part in the velocity normal to the stretching sheet, has been assumed. Streamline patterns and skin friction coefficients are discussed for various values of nondimensional physical parameters. The result of the analysis reveals that the combined effect of the non-dimensional viscoelastic parameter and Hartmann number is to increase significantly the values of skin friction coefficient, whereas, the combined effect of the nondimensional constant mass flux parameter and modified linear mass flux parameter is to reduce largely the values of skin friction coefficient. For positive values of the linear mass flux parameter the stream functions attain a positive slope away from the origin while they attain a negative slope everywhere for zero value. The limiting cases of our results yield the results of Andersson (1992) and Kumaran and Ramanaiah (1996).

10

Finite amplitude long wave instability of a film of conducting fluid flowing down an inclined plane in presence of electromagnetic field

Dandapat B. S., Mukhopadhyay A.

International Journal of Applied Mechanics and Engineering

|

2003

|

Vol. 8, no 3

379-383

EN

Stability characteristics of a thin conducting liquid film flowing down, on a non-conducting plane in the presence of the electromagnetic field is investigated under the assumption of a small magnetic Reynolds number. A surface evolution equation is derived by using the long-wave approximation method. A linear and non-linear stability analysis of the evolution equation shows that the magnetic field stabilizes the flow whereas the electric field stabilizes or destabilizes the flow depending on its orientation with the flow. It is found that both the subcritical instability and supercritical stability are possible in a finite amplitude regime. Two critical Hartmann numbers Mc and Mc>(Mc) are observed for subcritical and supercritical zones respectively. The existence of a subcritical unstable zone may be ruled out when Mc>Mc which is independent of other parameters whereas supercritical and explosive zones are possible till Mc

11

Suppression of elastic plate oscillations in MHD-flow by feedback control

Selezov I., Fratamico G.

Vibrations in Physical Systems

|

2002

|

Vol. 20

262--263

12

Secondary flow in MHD

Kucaba-Pietal A., Lechowicz J.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

|

1998

|

z. 6

205-211

EN

The axisymrnetrical flow of the electrically conducting fluid is considered in the presence of a converging-diverging current flow. The governing equations are discretized using finite difference method. The numerical procedure is based on time-marching methods [4]. The effect of the Re number and the magnetic pressure C on the value of velocity along the tube axis was examined.

PL

Przedstawiono wstępne wyniki numeryczne otrzymane dla przepływu, MHD w obecności zbieżno - rozbieżnego pola elektrycznego. Program obliczeniowy został napisany na podstawie metody opisanej w [4]. Badano wpływ liczby Reynoldsa Re i ciśnienia magnetycznego C na powstawanie przepływu wtórnego.