The effect of rotation on the problem of fiber-reinforced under generalized magnetothermoelasticity subject to thermal loading due to laser pulse: a comparison of different theories

2014 ◽  
Vol 92 (9) ◽  
pp. 1002-1015 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
W.M. Hasona ◽  
Elsayed M. Abd-Elaziz
Keyword(s):  
Magnetic Field ◽  
Laser Pulse ◽  
Thermal Loading ◽  
Normal Mode Analysis ◽  
Elastic Half Space ◽  
Mode Analysis ◽  
Fiber Reinforced ◽  
Gaussian Laser Beam ◽  
Magnetic Field Rotation ◽  
Non Gaussian

In the present paper, we introduce the coupled theory, Lord–Schulman theory, and Green–Lindsay theory to study the influences of a magnetic field and rotation on a two-dimensional problem of fiber-reinforced thermoelasticity subject to thermal loading by a laser pulse. The material is a homogeneous isotropic elastic half-space and is heated by a non-Gaussian laser beam with pulse duration of 8 ps. The method applied here is to use normal mode analysis to solve a thermal shock problem. Deformation of a body depends on the nature of the force applied as well as the type of boundary conditions. Numerical results for the temperature, displacement, and thermal stress components are given and illustrated graphically in the absence and the presence of the magnetic field, rotation, reinforcement, and for two different values of time.

Effect of magnetic field on a rotating thermoelastic medium with voids under thermal loading due to laser pulse with energy dissipation

2014 ◽  
Vol 92 (11) ◽  
pp. 1359-1371 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
Magda E.M. Zidan ◽  
Mohamed I.M. Hilal
Keyword(s):  
Magnetic Field ◽  
Laser Pulse ◽  
Thermal Loading ◽  
Volume Fraction ◽  
Plane Surface ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Gaussian Laser Beam ◽  
Thermoelastic Solid ◽  
Non Gaussian

This investigation deals with the rotation of magneto-thermoelastic solid with voids subjected to thermal loading due to laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam. The entire porous medium is rotated with a uniform angular velocity. The problem is studied in the context of Green–Naghdi (GN) theory of types II and III, with the effect of rotation, magnetic field, thermal loading and voids. Normal mode analysis is used to solve the physical problem to obtain the exact expressions for the displacement components, stresses, temperature distribution, and change in the volume fraction field, which have been shown graphically by comparison between two types of GN theory (types II and III) in the presence and the absence of rotation and magnetic field and for two values of time on thermoelastic material with voids.

2-D Analysis of Generalized Thermoelastic Porous Medium under the Effect of Laser Pulse and Microtemperature

2021 ◽  
pp. 2150126
Author(s):  
Amnah M. Alharbi ◽  
Mohamed I. A. Othman ◽  
Elsayed M. Abd-Elaziz
Keyword(s):  
Laser Pulse ◽  
Normal Mode Analysis ◽  
Moment Tensor ◽  
Elastic Half Space ◽  
Mode Analysis ◽  
Gaussian Laser Beam ◽  
Physical Response ◽  
Generalized Thermoelastic ◽  
Non Gaussian ◽  
Graphical Illustration

The paper presents the analytical solutions for a generalized thermoelastic medium consisting of microtemperatures and voids subjected to a laser pulse loading the medium thermally. The 0.02 ps pulse duration of the non-Gaussian laser beam is apt for heating a homogenous isotropic elastic half-space. A method called the normal mode analysis is employed to evaluate numerically the effects of various variables such as the micro-temperature vector, variation in the fraction field of the volume, first heat flux moment tensor, temperature distribution on the stresses and displacement components of the medium. In addition, the graphical illustration of the physical response of the medium has been presented in the presence and absence of void parameters, as well as in the presence of laser pulse with two different acting periods.

The influence of thermal loading due to laser pulse on generalized micropolar thermoelastic solid with comparison of different theories

2014 ◽  
Vol 10 (3) ◽  
pp. 328-345 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
W.M. Hasona ◽  
Elsayed M. Abd-Elaziz
Keyword(s):  
Laser Pulse ◽  
Thermal Loading ◽  
Plane Surface ◽  
Normal Mode Analysis ◽  
Relaxation Times ◽  
Mode Analysis ◽  
Gaussian Laser Beam ◽  
Content Type ◽  
Thermoelastic Solid ◽  
Non Gaussian

Purpose – The purpose of this paper is to introduce the coupled theory, Lord-Shulman theory with one relaxation time and Green-Lindsay theory with two relaxation times to study the influence of rotation on generalized micropolar thermoelasticity subject to thermal loading due to laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam with pulse duration of 8 ps. Design/methodology/approach – The problem has been solved numerically by using the normal mode analysis. Findings – The thermal shock problem is studied to obtain the exact expressions for the displacement components, force stresses, temperature, couple stresses and micro-rotation. The distributions of the considered variables are illustrated graphically. Comparisons are made with the results predicted by three theories in the presence and absence of laser pulse and for different values of time. Originality/value – Generalized micropolar thermoelastic solid.

Memory-dependent derivative effect on wave propagation of micropolar thermoelastic medium under pulsed laser heating with three theories

2019 ◽  
Vol 30 (3) ◽  
pp. 1025-1046 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
Sudip Mondal
Keyword(s):  
Wave Propagation ◽  
Laser Pulse ◽  
Thermal Loading ◽  
Plane Surface ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Phase Lag ◽  
Gaussian Laser Beam ◽  
Content Type ◽  
Non Gaussian

Purpose The purpose of this paper is to introduce the phase-lag models (Lord-Shulman, dual-phase-lag and three-phase-lag) to study the effect of memory-dependent derivative and the influence of thermal loading due to laser pulse on the wave propagation of generalized micropolar thermoelasticity. The bounding plane surface is heated by a non-Gaussian laser beam with a pulse duration of 10 nanoseconds. Design/methodology/approach The normal mode analysis technique is used to obtain the exact expressions for the displacement components, the force stresses, the temperature, the couple stresses and the micro-rotation. Comparisons are made with the results predicted by three theories of the authors’ interest. Excellent predictive capability is demonstrated at a different time also. Findings The effect of memory-dependent derivative and the heat laser pulse on the displacement, the temperature distribution, the components of stress, the couple stress and the microrotation vector have been depicted graphically. Research limitations/implications Some particular cases are also deduced from the present investigation. Originality/value The numerical results are presented graphically and are compared with different three theories for both in the presence and absence of memory-dependent effect and with the results predicted under three theories for two different values of the time.

Effect of Magnetic Field on Thermoelastic Micro-Elongated Solid with Diffusion Under Dual-Phase-Lag Model

2021 ◽  
pp. 2150189
Author(s):  
Amnah M. Alharbi ◽  
Mohamed I. A. Othman ◽  
Elsayed M. Abd-Elaziz
Keyword(s):  
Magnetic Field ◽  
Laser Pulse ◽  
Thermal Loading ◽  
Normal Mode Analysis ◽  
Concentration Field ◽  
Mode Analysis ◽  
Phase Lag ◽  
Dual Phase ◽  
Lag Model ◽  
Non Gaussian

This study considers a thermoelastic micro-elongated solid which is being heated by a laser pulse in order to investigate the corresponding impact of thermal loading and magnetic field. A laser beam that is non-Gaussian in nature is used to heat the surface of the bounded plane with a pulse duration [Formula: see text][Formula: see text]ps. The dual-phase-lag (DPL) model is considered to develop a better understanding of the problem. Also, the problems are solved using normal mode analysis as well as it helps in attaining the appropriate expressions for micro-rotation, components of displacement, the force stress, couple stress, concentration field, the temperature distribution the scalar micro-elongated function, and the micro-stress. The results obtained from the thermal variations are validated by comparing them to Coupled Theory (CT) of thermo-elasticity, Lord and Shulman (L–S) theory, and the DPL model. The graphical illustration of these comparisons has been presented as it helps in exploring the impacts of the laser pulse at two different times and the magnetic field parameter. The investigation also helped deduce some specific cases of interest.

scholarly journals Effect of Magnetic Field on Thermosolutal Instability of Rotating Ferromagnetic Fluid Under Varying Gravity Field

2021 ◽  
Vol 26 (1) ◽  
pp. 201-214
Author(s):  
S. K. Pundir ◽  
P. K. Nadian ◽  
R. Pundir
Keyword(s):  
Magnetic Field ◽  
Gravity Field ◽  
Fluid Layer ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Free Boundaries ◽  
Magnetic Field Rotation ◽  
Stabilizing Effect ◽  
Ferromagnetic Fluid ◽  
Solute Gradient

AbstractThis paper deals with the theoretical investigation of the effect of a magnetic field, rotation and magnetization on a ferromagnetic fluid under varying gravity field. To find the exact solution for a ferromagnetic fluid layer contained between two free boundaries, we have used a linear stability analysis and normal mode analysis method. For the case of stationary convection, a stable solute gradient has a stabilizing effect, while rotation has a stabilizing effect if λ>0 and destabilizing effect if λ<0. Further, the magnetic field is discovered to have both a stabilizing and destabilizing effect for both λ>0 and λ<0. It is likewise discovered that magnetization has a stabilizing effect for both λ>0 and λ<0 in the absence of the stable solute gradient. Graphs have been plotted by giving numerical values of various parameters. In the absence of rotation, magnetic field and stable solute gradient, the principle of exchange of stabilities is found to hold true for certain conditions.

Effect of gravity on generalized thermoelastic diffusion due to laser pulse using dual-phase-lag model

2018 ◽  
Vol 14 (3) ◽  
pp. 457-481 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
Ebtesam E.M. Eraki
Keyword(s):  
Plane Surface ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Graphical Form ◽  
Phase Lag ◽  
Dual Phase ◽  
Field Equations ◽  
Gaussian Laser Beam ◽  
Content Type ◽  
Non Gaussian

Purpose The purpose of this paper is to obtain a general solution to the field equations of generalized thermo-diffusion in an infinite thermoelastic body under the effect of gravity in the context of the dual-phase-lag (DPL) model. The half space is considered made of an isotropic homogeneous thermoelastic material. The boundary plane surface is heated by a non-Gaussian laser beam. Design/methodology/approach An exact solution to the problem is obtained using the normal mode analysis. Findings The derived expressions are computed numerically for copper and the results are presented in graphical form. Originality/value Comparisons are made with the results predicted by Lord-Shulman theory and DPL model for different values of time and in the presence and absence of gravity as well as diffusion.

scholarly journals Mathematical Modeling on Rotational Magneto-Thermoelastic Phenomenon under Gravity and Laser Pulse considering Four Theories

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Hammad Alotaibi ◽  
S. M. Abo-Dahab ◽  
E. M. Khalil ◽  
S. Abdel-Khalek ◽  
Emad E. Mahmoud ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Laser Pulse ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Analysis Technique ◽  
Gravity And Magnetic ◽  
System Equations ◽  
Analytical Expressions ◽  
Special Case ◽  
Gl Theory

The aim of this investigation is making mathematical model for the variation in laser pulse, rotational gravity, and magnetic fields on the generalized thermoelastic homogeneous isotropic half-space. The governing dynamical system equations have been formulated considering the four thermoelastic models: coupled (CT) model, Lord and Shulman (LS) model, Green and Lindsay (GL) theory, and Green and Naghdi (GN III) model. Normal mode analysis technique is used to obtain the analytical expressions for the displacement components, temperature, and mechanical and Maxwell’s stresses distribution. The effect of laser pulse, gravity, and magnetic field is studied by numerical examples and displayed graphically. A comparison has been made between the theories as well as the present results and agreement with it as a special case from this study. The results predict the strong effect of magnetic field, laser pulse, and gravity field on the wave propagation phenomenon.

Finite-Resistivity Effects on Rayleigh-Taylor Instability of a Stratified Plasma Including Suspended Particles

1985 ◽  
Vol 40 (8) ◽  
pp. 826-833
Author(s):  
Rajkamal Sanghvi ◽  
R. K. Chhajlani
Keyword(s):  
Magnetic Field ◽  
Kinematic Viscosity ◽  
Normal Mode Analysis ◽  
Longitudinal Mode ◽  
Transverse Mode ◽  
Suspended Particles ◽  
Wave Number ◽  
Mode Analysis ◽  
Free Boundaries ◽  
Horizontal Magnetic Field

The Rayleigh-Taylor (RT) instability of a stratified and viscid magnetoplasma including the effects of "finite-resistivity and suspended particles is investigated using normal mode analysis. The horizontal magnetic field and the viscosity of the medium are assumed to be variable. The dispersion relation, which is obtained for the general case on employing boundary conditions appropriate to the case of two free boundaries, is then specialized for the longitudinal and transverse modes. It is found that the criterion of stable stratification remains essentially unchanged and that the unstable stratification for the longitudinal mode can be stabilized for a certain wave number band, whereas the transverse mode remains unstable or all wave numbers which can be stabilized by a suitable choice of the magnetic field for vanishing resistivity. Thus, resistivity is found to have a destabilizing influence on the RT configuration. The growth rates of the unstable RT modes with the kinematic viscosity and the relaxation frequency parameter of the suspended particles have been analytically evaluated. Dust (suspended particles) tends to stabilize the configuration when the medium is considered viscid with infinite conductivity. The kinematic viscosity has a stabilizing influence on the ideal plasma modes.

scholarly journals TRIPLE-DIFFUSIVE CONVECTION IN WALTERS’ (MODEL B’) FLUID WITH VARYING GRAVITY FIELD SATURATING A POROUS MEDIUM

2013 ◽  
Vol 35 (3) ◽  
pp. 45-56 ◽  
Author(s):  
S.K. Kango ◽  
G.C. Rana ◽  
Ramesh Chand
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Gravity Field ◽  
Normal Mode Analysis ◽  
Sufficient Conditions ◽  
Mode Analysis ◽  
Stationary Convection ◽  
Analysis Theory ◽  
Diffusive Convection ◽  
Medium Permeability

Abstract The Triple-Diffusive convection in Walters’ (Model B') fluid with varying gravity field is considered in the presence of uniform vertical magnetic field in porous medium. For the case of stationary convection, the magnetic field, varying gravity field and the stable solute gradients have stabilizing effects whereas the medium permeability has destabilizing (or stabilizing) effect on the system under certain conditions. A linear stability analysis theory and normal mode analysis method have been carried out to study the onset convection. The kinematic viscoelasticity has no effect on the stationary convection. The solute gradients, magnetic field, varying gravity field, porosity and kinematic viscoelasticity introduce oscillatory modes in the system, which were non-existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained. The results are also shown graphically.

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