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1 – 10 of over 20000Rajneesh Kumar, Aseem Miglani and Sanjay Kumar
The purpose of this paper is establish a model of the equations of a two‐dimensional problem of fluid saturated porous medium for a half space.
Abstract
Purpose
The purpose of this paper is establish a model of the equations of a two‐dimensional problem of fluid saturated porous medium for a half space.
Design/methodology/approach
A state space approach has been applied to solve the problem. Normal mode analysis is used to obtain the exact expressions for normal stress, tangential stress and pore pressure.
Findings
A computer programme is developed and numerical results are obtained for normal stress, tangential stress and pore pressure and depicted graphically for a special model. A particular case of interest has also been deduced from the present investigation.
Originality/value
The disturbance due to force in normal and tangential direction and porosity effect have been observed by the method of normal mode analysis.
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D. Murugan and R. Sekar
The effect of magnetic field dependent (MFD) viscosity on the onset of convection in a ferromagnetic fluid layer heated from below saturating rotating porous medium in the…
Abstract
Purpose
The effect of magnetic field dependent (MFD) viscosity on the onset of convection in a ferromagnetic fluid layer heated from below saturating rotating porous medium in the presence of vertical magnetic field is investigated theoretically by using Darcy model. The resulting eigen value problem is solved using the regular perturbation technique. Both stationary and oscillatory instabilities have been obtained. It is found that increase in MFD viscosity and increase in magnetic Rayleigh number is to delay the onset of ferroconvection, while the nonlinearity of fluid magnetization has no influence on the stability of the system.
Design/methodology/approach
The thermal perturbation method is employed for analytical solution. A theory of linear stability analysis and normal mode technique have been carried out to analyze the onset of convection for a fluid layer contained between two impermeable boundaries for which an exact solution is obtained.
Findings
The conditions for the system to stabilize both by stationary and oscillatory modes are studied. Even for the oscillatory system of particular frequency dictated by physical conditions, the critical Rayleigh numbers for oscillatory mode of the system were found to be greater than for the stationary mode. The system gets destabilized for various physical parameters only through stationary mode. Hence, the analysis is restricted to the stationary mode. To the Coriolis force, the Taylor number Ta is calculated to discuss the results. It is found that the system stabilizes through stationary mode for values of and for oscillatory instability is favored for Ta > 104. Therefore the Taylor number Ta leads to stability of the system. For larger rotation, magnetization leads to destabilization of the system. The MFD viscosity is found to stabilize the system.
Originality/value
This research paper is new and original.
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Devender Sheoran, Rajesh Kumar, Seema Thakran and Kapil Kumar Kalkal
The purpose of this paper is to study two-dimensional deformations in a nonlocal, homogeneous, isotropic, rotating thermoelastic medium with temperature-dependent properties under…
Abstract
Purpose
The purpose of this paper is to study two-dimensional deformations in a nonlocal, homogeneous, isotropic, rotating thermoelastic medium with temperature-dependent properties under the purview of the Green-Naghdi model II of generalized thermoelasticity. The formulation is subjected to a mechanical load.
Design/methodology/approach
The normal mode analysis technique is adopted to procure the exact solution of the problem.
Findings
For isothermal and insulated boundaries, discussions have been made to highlight the influences of rotational speed, nonlocality, temperature-dependent properties and time on the physical quantities.
Originality/value
The exact expressions for the displacement components, stresses and temperature field are obtained in the physical domain. These are also calculated numerically for a magnesium crystal-like material and depicted through graphs to observe the variations of the considered physical quantities. The present study is useful and valuable for the analysis of problems involving mechanical shock, rotational speed, nonlocal parameter, temperature-dependent properties and elastic deformation.
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Devender Sheoran, Komal Yadav, Baljit Singh Punia and Kapil Kumar Kalkal
The purpose of this paper is to analyse the transient effects in a functionally graded photo-thermoelastic (TE) medium with gravity and rotation by considering two generalised TE…
Abstract
Purpose
The purpose of this paper is to analyse the transient effects in a functionally graded photo-thermoelastic (TE) medium with gravity and rotation by considering two generalised TE theories: Lord–Shulman (LS) and Green–Lindsay (GL). The governing equations are derived in rectangular Cartesian coordinates for a two dimensional problem.
Design/methodology/approach
All the physical properties of the semiconductor are supposed to vary exponentially with distance. The analytical solution is procured by employing normal mode technique on the resulting non-dimensional coupled field equations with appropriate boundary conditions.
Findings
For the mechanically loaded thermally insulated surface, normal displacement, stress components, temperature distribution and carrier density are calculated numerically with the help of MATLAB software for a silicon semiconductor and displayed graphically. Some particular cases of interest have also been deduced from the present results.
Originality/value
The effects of rotation and non-homogeneity on the different physical fields are investigated on the basis of analytical and numerical results. Comparisons are made with the results predicted by GL theory in the presence and absence of gravity for different values of time. Comparisons are also made between the three theories in the presence of rotation, gravity and in-homogeneity. Such problems are very important in many dynamical systems.
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Mohamed I.M. Hilal and Mohamed I.A. Othman
The purpose of this paper is to discuss the problem of thermoelasticity with voids under the gravity field in the context of a general form of heat conduction equation with some…
Abstract
Purpose
The purpose of this paper is to discuss the problem of thermoelasticity with voids under the gravity field in the context of a general form of heat conduction equation with some particular cases. The normal mode method used is to obtain the physical quantities.
Design/methodology/approach
The analytical method used was the normal mode.
Findings
Numerical results for the physical quantities are presented graphically and the results are analyzed thereafter. The comparisons are established between the theories for the physical quantities during the constant time and gravity and were shown graphically.
Originality/value
In the present work, the authors shall establish the general form for the heat conduction equation which contains the seven theories as well as the special cases in thermoelasticity with voids. The problem is very important in many dynamical systems.
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Sunita Deswal, Devender Sheoran and Kapil Kumar Kalkal
The purpose of this paper is to establish a model of two-dimensional half-space problem of linear, isotropic, homogeneous, initially stressed, rotating thermoelastic medium with…
Abstract
Purpose
The purpose of this paper is to establish a model of two-dimensional half-space problem of linear, isotropic, homogeneous, initially stressed, rotating thermoelastic medium with microtemperatures. The expressions for different physical variables such as displacement distribution, stress distribution, temperature field and microtemperatures are obtained in the physical domain.
Design/methodology/approach
Normal mode analysis technique is adopted to procure the exact solution of the problem.
Findings
Numerical computations have been carried out with the help of MATLAB programming, and the results are illustrated graphically. Comparisons are made to show the effects of rotation, time and microtemperatures on the resulting quantities. The graphical results indicate that the effects of rotation, microtemperatures and time are very pronounced on the field variables.
Originality/value
In the present work, we have investigated the effects of rotation, time and microtemperature in an initially stressed thermoelastic medium. Although various investigations do exist to observe the disturbances in a thermoelastic medium under the effects of different parameters, the work in its present form, i.e. the disturbances in a thermoelastic medium in the presence of angular velocity, initial stress and microtemperature have not been studied till now. The present work is useful and valuable for analysis of problems involving coupled thermal shock, rotation parameter, microtemperatures and elastic deformation.
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Rachaita Dutta, Soumik Das, Shishir Gupta, Aditi Singh and Harsh Chaudhary
The purpose of this study is to analyze the thermo-diffusion process in a semi-infinite nonlocal fiber-reinforced double porous thermoelastic diffusive material with voids…
Abstract
Purpose
The purpose of this study is to analyze the thermo-diffusion process in a semi-infinite nonlocal fiber-reinforced double porous thermoelastic diffusive material with voids (FRDPTDMWV) in light of the fractional-order Lord–Shulman thermo-elasto-diffusion (LSTED) model. By virtue of Eringen’s nonlocal elasticity theory, the governing equations for the considered material are developed. The free surface of the substrate is governed by the inclined mechanical load and thermal and chemical shocks.
Design/methodology/approach
With the aid of the normal mode technique, the solutions of the nondimensional coupled governing equations have been obtained.
Findings
The expressions of field variables are obtained analytically. By using MATHEMATICA software, various graphical implementations are presented to describe the impacts of angle of inclination, fractional-order and nonlocality parameters. The present model is also validated on the basis of some comparative studies with some preestablished cases.
Originality/value
As observed from the literature survey, many different studies have been carried out by taking into account the deformation analysis in nonlocal double porous thermoelastic material structures and thermo-mechanical interaction in fiber-reinforced medium under fractional-order thermoelasticity theories. However, to the best of the authors’ knowledge, no research emphasizing the thermo-elasto-diffusive interactions in a nonlocal FRDPTDMWV has been carried out. Moreover, the effect of fractional-order LSTED theory on fiber-reinforced thermoelastic diffusive half-space with double porosity has not been illuminated till now, which significantly defines the novelty of the conducted research.
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Sandeep Singh Sheoran, Shilpa Chaudhary and Kapil Kumar Kalkal
The purpose of this paper is to study the transient thermoelastic interactions in a nonlocal rotating magneto-thermoelastic medium with temperature-dependent properties…
Abstract
Purpose
The purpose of this paper is to study the transient thermoelastic interactions in a nonlocal rotating magneto-thermoelastic medium with temperature-dependent properties. Three-phase-lag (TPL) model of generalized thermoelasticity is employed to study the problem. An initial magnetic field with constant intensity acts parallel to the bounding plane. Therefore, Maxwell's theory of electrodynamics has been effectively introduced and the expression for Lorentz's force is obtained with the help of modified Ohm's law.
Design/methodology/approach
The normal mode technique has been adopted to solve the resulting non-dimensional coupled field equations to obtain the expressions of physical field variables.
Findings
For uniformly distributed thermal load, normal displacement, temperature distribution and stress components are calculated numerically with the help of MATLAB software for a copper material and the results are illustrated graphically. Some particular cases of interest are also deduced from the present study.
Originality/value
Influences of nonlocal parameter, rotation, temperature-dependent properties, magnetic field and time are carefully analyzed for mechanically stress free boundary and uniformly distributed thermal load. The present work is useful and valuable for analysis of problem involving thermal shock, nonlocal parameter, temperature-dependent elastic and thermal moduli.
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Mohamed I.A. Othman, W.M. Hasona and Elsayed M. Abd-Elaziz
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…
Abstract
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.
Details
Keywords
A two‐dimensional coupled problem in electromagneto‐thermoelasticity for a thermally and electrically conducting half‐space solid whose surface is subjected to a thermal shock is…
Abstract
A two‐dimensional coupled problem in electromagneto‐thermoelasticity for a thermally and electrically conducting half‐space solid whose surface is subjected to a thermal shock is considered. The problem is in the context of the Lord and Shulman’s generalized thermoelasticity with one relaxation time. There acts an initial magnetic field parallel to the plane boundary of the half‐space. The medium deformed because of thermal shock and due to the application of the magnetic field, there result an induced magnetic and an induced electric field in the medium. The Maxwell’s equations are formulated and the electromagneto‐thermoelastic coupled governing equations are established. The normal mode analysis is used to obtain the exact expressions for the considered variables. The distributions of the considered variables are represented graphically. From the distributions, it can be found the wave type heat propagation in the medium. This indicates that the generalized heat conduction mechanism is completely different from the classic Fourier’s in essence. In generalized thermoelasticity theory heat propagates as a wave with finite velocity instead of infinite velocity in medium. Comparisons are made with the results predicted by the coupled theory for two values of time.
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