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Volume 27 (2022): Issue 4 (December 2022)

Volume 27 (2022): Issue 3 (September 2022)

Volume 27 (2022): Issue 2 (June 2022)

Volume 27 (2022): Issue 1 (March 2022)

Volume 26 (2021): Issue 4 (December 2021)

Volume 26 (2021): Issue 3 (September 2021)

Volume 26 (2021): Issue 2 (June 2021)

Volume 26 (2021): Issue 1 (March 2021)

Volume 25 (2020): Issue 4 (December 2020)

Volume 25 (2020): Issue 3 (September 2020)

Volume 25 (2020): Issue 2 (June 2020)

Volume 25 (2020): Issue 1 (March 2020)

Volume 24 (2019): Issue 4 (December 2019)

Volume 24 (2019): Issue 3 (September 2019)

Volume 24 (2019): Issue 2 (June 2019)

Volume 24 (2019): Issue 1 (March 2019)

Volume 23 (2018): Issue 4 (November 2018)

Volume 23 (2018): Issue 3 (August 2018)

Volume 23 (2018): Issue 2 (May 2018)

Volume 23 (2018): Issue 1 (February 2018)

Volume 22 (2017): Issue 4 (December 2017)

Volume 22 (2017): Issue 3 (August 2017)

Volume 22 (2017): Issue 2 (May 2017)

Volume 22 (2017): Issue 1 (February 2017)

Volume 21 (2016): Issue 4 (December 2016)

Volume 21 (2016): Issue 3 (August 2016)

Volume 21 (2016): Issue 2 (May 2016)

Volume 21 (2016): Issue 1 (February 2016)

Volume 20 (2015): Issue 4 (December 2015)

Volume 20 (2015): Issue 3 (August 2015)

Volume 20 (2015): Issue 2 (May 2015)

Volume 20 (2015): Issue 1 (February 2015)

Volume 19 (2014): Issue 4 (December 2014)

Volume 19 (2014): Issue 3 (August 2014)

Volume 19 (2014): Issue 2 (May 2014)

Volume 19 (2014): Issue 1 (February 2014)

Volume 18 (2013): Issue 4 (December 2013)

Volume 18 (2013): Issue 3 (August 2013)

Volume 18 (2013): Issue 2 (June 2013)

Volume 18 (2013): Issue 1 (March 2013)

Journal Details
Format
Journal
eISSN
2353-9003
ISSN
1734-4492
First Published
19 Apr 2013
Publication timeframe
4 times per year
Languages
English

Search

Volume 24 (2019): Issue 3 (September 2019)

Journal Details
Format
Journal
eISSN
2353-9003
ISSN
1734-4492
First Published
19 Apr 2013
Publication timeframe
4 times per year
Languages
English

Search

15 Articles
Open Access

Role of Brownian Motion and Thermophoresis Effects on Hydromagnetic Flow of Nanofluid Over a Nonlinearly Stretching Sheet with Slip Effects and Solar Radiation

Published Online: 09 Aug 2019
Page range: 489 - 508

Abstract

Abstract

Hydromagnetic flow of water based nanofluids over a nonlinearly stretching sheet in the presence of velocity slip, temperature jump, magnetic field, nonlinear thermal radiation, thermophoresis and Brownian motion has been studied. The article focuses on Cu water nanofluid and Ag water nanofluid. The similarity transformation technique is adopted to reduce the governing nonlinear partial differential equations into nonlinear ordinary differential equations and then they are solved numerically utilizing the Nachistem – Swigert shooting method along with the fourth order Runge Kutta integration technique. The influence of physical parameters on the flow, temperature and nanoparticle volume fraction are presented through graphs. Also the values of the skin friction coefficient at the wall and nondimensional rate of heat transfer are given in a tabular form. A comparative study with previous published results is also made.

Keywords

  • nanofluid
  • MHD
  • radiation
  • slip flow
  • stretching sheet
Open Access

Failure Analysis of Laminated Composite Plate Under Hygro-Thermo Mechanical Load and Optimisation

Published Online: 09 Aug 2019
Page range: 509 - 526

Abstract

Abstract

Failure analysis of laminated composite plates for different mechanical, thermo mechanical and hygro-thermo mechanical loads for different ply thicknesses, stacking sequences, fiber orientation angles and composite material systems is presented in the paper. A comparative study of different failure theories is also presented in the paper. The effect of fiber orientation angles on the first ply failure load is also studied. A hybrid composite laminate is developed based on the first ply failure load which minimizes weight and cost. The last ply failure load based on fully discounted method is calculated for different stacking sequences. An optimum composite material system and laminate layup is studied for a targeted strength ratio which minimizes weight.

Keywords

  • first ply failure load
  • last ply failure load
  • strength ratio
  • fiber orientation angle
  • hybrid composite
Open Access

Simultaneous Chemical Reactions Effect on Dispersion of a Solute in Peristaltic Propulsion of a Newtonian Fluid in an Inclined Channel with Wall Properties

Published Online: 09 Aug 2019
Page range: 527 - 538

Abstract

Abstract

In this paper, the dispersion of a solute in the peristaltic propulsion of an incompressible and viscous fluid through a permeable medium under the influence of wall properties with simultaneous homogeneous, heterogeneous chemical reactions in an inclined uniform channel has been studied. The issue is studied through conditions of Taylor’s limit and long wavelength hypothesis. The mean effective coefficient of scattering expression is computed and outcomes are interpreted physically through graphs.

Keywords

  • dispersion
  • inclined channel
  • viscous fluid
  • peristaltic propulsion
  • wall properties
Open Access

Electrically Conducting Flow through Exponential Power Law Fluid with Variable Thermal Conductivity

Published Online: 09 Aug 2019
Page range: 539 - 548

Abstract

Abstract

The problem of exponential law of steady, incompressible fluid flow in boundary layer and heat transfer are studied in an electrically conducting fluid over a semi-infinite vertical plate assuming the variable thermal conductivity in the presence of a uniform magnetic field. The governing system of equations including the continuity equation, momentum equation and energy equation have been transformed into nonlinear coupled ordinary differential equations using appropriate similarity variables. All the numerical and graphical solutions are obtained through the use of Maple software. The solutions are found to be dependent on three dimensionless parameters including the magnetic field parameter M, thermal conductivity parameter β and Prandtl number Pr. Representative velocity and temperature profiles are presented at various values of the governing parameters. The skin-friction coefficient and the rate of heat transfer are also calculated for different values of the parameters.

Keywords

  • MHD
  • similarity solution
  • variable properties
  • boundary layer flow
  • exponential law
Open Access

The Characterization of the Stress Fields Near a Crack Tip for a Compact Specimen for Elastic-Plastic Materials Dominated by the Plane Strain State

Published Online: 09 Aug 2019
Page range: 549 - 576

Abstract

Abstract

The paper presents a comprehensive analysis of the stress field near a crack tip for a compact specimen dominated by the plane strain state using the finite element method. The analysis also includes the calculation of some parameters of in-plane constraints, both for small and large strain assumptions. It discusses the influence of the material characteristic, relative crack length and external load for the stress field, and the in-plane constraint parameter. The approximation formulas for some in-plane constraint parameters are presented.

Keywords

  • fracture mechanics
  • C(T)
  • stress field
  • FEM
  • constraints
  • plane strain
  • plastic zone
  • crack
Open Access

MHD Slip Flow Past an Extending Surface with Third Type Boundary Condition and Thermal Radiation Effects

Published Online: 09 Aug 2019
Page range: 577 - 590

Abstract

Abstract

MHD slip flow past an extending surface with third type (convective) boundary condition and thermal radiation is analysed. The governing momentum and energy equations are converted into set of nonlinear ordinary differential equations using appropriate similarity transformations. The Fourth-Order Runge-Kutta shooting method is applied for obtaining the numerical solution of the resulting nonlinear ordinary differential equations. The numerical results for velocity and temperature distribution are found for different values of the vital parameters, namely: the magnetic interaction factor, slip factor, convective factor, Prandtl number and radiation factor and are presented graphically, and discussed.

Keywords

  • third type (convective) boundary condition
  • slip flow
  • thermal radiation
  • extending surface
Open Access

Trajectory Planning of the Humanoid Manipulator

Published Online: 09 Aug 2019
Page range: 591 - 602

Abstract

Abstract

The paper presents a method of planning a collision-free trajectory for a humanoid manipulator mounted on a rail system. The task of the robot is to move its end-effectors from the current position to the given final location in the workspace. The method is based on a redundancy resolution at the velocity level. In addition to this primary task, secondary objectives are also taken into account. The motion of the robot is planned in order to maximize a manipulability measure in purpose of avoiding manipulator singularities. State inequality constraints resulting from collision avoidance conditions are also considered. A computer example involving a humanoid manipulator operating in a three dimensional task space is also presented.

Keywords

  • humanoid manipulator
  • redundancy resolution
  • collision avoidance
  • manipulability measure
Open Access

Phase-Lag Effects in Skin Tissue During Transient Heating

Published Online: 09 Aug 2019
Page range: 603 - 623

Abstract

Abstract

A three-phase-lag (TPL) model is proposed to describe heat transfer in a finite domain skin tissue with temperature dependent metabolic heat generation. The Laplace transform method is applied to solve the problem. Three special types of heat flux are applied to the boundary of skin tissue for thermal therapeutic applications. The depth of tissue is influenced by the different oscillation heat flux. The comparison between the TPL and dual-phase-lag (DPL) models is analyzed and the effects of phase lag parameters (τq, τt and τv) and material (k*) on the tissue temperature distribution are presented graphically.

Keywords

  • bioheat transfer
  • skin tissue
  • three-phase-lag
  • Laplace transform
  • transient heating
Open Access

Generation of Surface Waves Due to Initial Axisymmetric Surface Disturbance in Water with a Porous Bottom

Published Online: 09 Aug 2019
Page range: 625 - 644

Abstract

Abstract

A two-dimensional Cauchy Poisson problem for water with a porous bottom generated by an axisymmetric initial surface disturbance is investigated here. The problem is formulated as an initial value problem for the velocity potential describing the motion in the fluid. The Laplace and Hankel transform techniques have been used in the mathematical analysis to obtain the form of the free surface in terms of a multiple infinite integral. This integral is then evaluated asymptotically by the method of stationary phase. The asymptotic form of the free surface is depicted graphically in a number of figures for different values of the porosity parameter and for different types of initial disturbances.

Keywords

  • axisymmetric surface disturbance
  • porous bottom
  • Laplace and Hankel transform
  • method of stationary phase
  • free surface depression
Open Access

The Effect of Slip Velocity on Unsteady Peristalsis MHD Blood Flow through a Constricted Artery Experiencing Body Acceleration

Published Online: 09 Aug 2019
Page range: 645 - 659

Abstract

Abstract

In this analysis, we present a theoretical study to examine the combined effect of both slip velocity and periodic body acceleration on an unsteady generalized non-Newtonian blood flow through a stenosed artery with permeable wall. A constant transverse magnetic field is applied on the peristaltic flow of blood, treating it as an elastico-viscous, electrically conducting and incompressible fluid. Appropriate transformation methods are adopted to solve the unsteady non-Newtonian axially symmetric momentum equation in the cylindrical polar coordinate system with suitably prescribed conditions. To validate the applicability of the proposed analysis, analytical expressions for the axial velocity, fluid acceleration, wall shear stress and volumetric flow rate are computed and for having an adequate insight to blood flow behavior through a stenosed artery, graphs have been plotted with varying values of flow variables, to analyse the influence of the axial velocity, wall shear stress and volumetric flow rate of streaming blood.

Keywords

  • elastico-viscous
  • slip velocity
  • selective permeability
  • peristalsis
  • stenosed artery

MSC 2010

  • 76Zxx
  • 76Wxx
Open Access

On Propagation of Rayleigh Type Surface Wave in Five Different Theories of Thermoelasticity

Published Online: 09 Aug 2019
Page range: 661 - 673

Abstract

Abstract

The governing equations for a homogeneous and isotropic thermoelastic medium are formulated in the context of coupled thermoelasticity, Lord and Shulman theory of generalized thermoelasticity with one relaxation time, Green and Lindsay theory of generalized thermoelasticity with two relaxation times, Green and Nagdhi theory of thermoelasticity without energy dissipation and Chandrasekharaiah and Tzou theory of thermoelasticity. These governing equations are solved to obtain general surface wave solutions. The particular solutions in a half-space are obtained with the help of appropriate radiation conditions. The two types of boundaries at athe surface of a half-space are considered namely, the stress free thermally insulated boundary and stress free isothermal boundary. The particular solutions obtained in a half-space satisfy the relevant boundary conditions at the free surface of the half-space and a frequency equation for the Rayleigh wave speed is obtained for both thermally insulated and isothermal cases. The non-dimensional Rayleigh wave speed is computed for aluminium metal to observe the effects of frequency, thermal relaxation time and different theories of thermoelasticity.

Keywords

  • generalized thermoelasticity
  • surface waves
  • Rayleigh wave
  • frequency equation
Open Access

Radiation Absorption and Chemical Reaction Effects on Rivlin-Ericksen Flow Past a Vertical Moving Porous Plate

Published Online: 09 Aug 2019
Page range: 675 - 689

Abstract

Abstract

An analysis has been carried out to study the combined effects of radiation absorption and chemical reaction on an incompressible, electrically conducting and radiating flow of a Rivlin-Ericksen fluid along a semi-infinite vertical permeable moving plate in the presence of a transverse applied magnetic field. It is assumed that the suction velocity, the temperature and the concentration at the wall are exponentially varying with time. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. A comparison is made with the available results in the literature for a special case and our results are in very good agreement with the known results. A parametric study of the physical parameters is made and results are presented through graphs and tables. The results indicate that the fluid velocity and temperature could be controlled by varying the radiation absorption.

Keywords

  • Rivlin-Ericksen fluid
  • radiation absorption
  • chemical reaction
  • variable temperature
  • concentration and suction
Open Access

Plane Waves in Thermo-Viscoelastic Material with Voids Under Different Theories of Thermoelasticity

Published Online: 09 Aug 2019
Page range: 691 - 708

Abstract

Abstract

Propagation of time harmonic plane waves in an infinite thermo-viscoelastic material with voids has been investigated within the context of different theories of thermoelasticity. The equations of motion developed by Iesan [1] have been extended to incorporate the Lord-Shulman theory (LST) and Green-Lindsay theory (GLT) of thermoelasticity. It has been shown that there exist three coupled dilatational waves and an uncoupled shear wave propagating with distinct speeds. The presence of thermal, viscosity and voids parameters is responsible for the coupling among dilatational waves. All the existing waves are found to be dispersive and attenuated in nature. The phase speeds and attenuation coefficients of propagating waves are computed numerically for a copper material and compared under different theories of thermo-elasticity. The expressions of energies carried along each wave have also been derived. All the computed numerical results have been depicted through graphs. It is found that the influence of CT and GLT is almost same on wave propagation, while LST influences the wave propagation differently.

Keywords

  • thermo-visco-elasticity
  • voids
  • waves
  • phase speed
  • attenuation
  • energy
Open Access

Unsteady Three-Dimensional MHD Nanofluid Flow Over a Stretching Sheet with Variable Wall Thickness and Slip Effects

Published Online: 09 Aug 2019
Page range: 709 - 724

Abstract

Abstract

The stretching sheets with variable thickness may occur in engineering applications more frequently than a flat sheet. Due to its various applications, in the present analysis we considered a three dimensional unsteady MHD nanofluid flow over a stretching sheet with a variable wall thickness in a porous medium. The effects of radiation, viscous dissipation and slip boundary conditions are considered. Buongiorno’s model is incorporated to study the combined effects of thermophoresis and Brownian motion. The dimensionless governing equations are solved by using MATLAB bvp4c package. The impact of various important flow parameters is presented and analysed through graphs and tables. It is interesting to note that all the three boundary layer thicknesses are diminished by slip parameters. Further, the unsteady parameter decreases the hydromagnetic boundary layer thickness.

Keywords

  • unsteady flow
  • magnetic field
  • Buongiorno’s model
  • variable wall thickness sheet
  • velocity
  • thermal and solutal slip
Open Access

Thermal Radiation, Chemical Reaction, Viscous and Joule Dissipation Effects on MHD Flow Embedded in a Porous Medium

Published Online: 09 Aug 2019
Page range: 725 - 737

Abstract

Abstract

An analysis is presented to study the effects of thermal radiation, chemical reaction, viscous and Joule dissipation on MHD free convection flow between a pair of infinite vertical Couette channel walls embedded in a porous medium. The fluid flows by a strong transverse magnetic field imposed perpendicularly to the channel wall on the assumption of a small magnetic Reynolds number. The governing non linear partial differential equations are transformed in to ordinary differential equations and are solved analytically. The effect of various parameters viz., Eckert number, electric conductivity, dynamic viscosity and strength of magnetic field on temperature profile has been discussed and presented graphically.

Keywords

  • thermal radiation
  • chemical reaction
  • Joule dissipation
  • viscous dissipation
  • porous medium
15 Articles
Open Access

Role of Brownian Motion and Thermophoresis Effects on Hydromagnetic Flow of Nanofluid Over a Nonlinearly Stretching Sheet with Slip Effects and Solar Radiation

Published Online: 09 Aug 2019
Page range: 489 - 508

Abstract

Abstract

Hydromagnetic flow of water based nanofluids over a nonlinearly stretching sheet in the presence of velocity slip, temperature jump, magnetic field, nonlinear thermal radiation, thermophoresis and Brownian motion has been studied. The article focuses on Cu water nanofluid and Ag water nanofluid. The similarity transformation technique is adopted to reduce the governing nonlinear partial differential equations into nonlinear ordinary differential equations and then they are solved numerically utilizing the Nachistem – Swigert shooting method along with the fourth order Runge Kutta integration technique. The influence of physical parameters on the flow, temperature and nanoparticle volume fraction are presented through graphs. Also the values of the skin friction coefficient at the wall and nondimensional rate of heat transfer are given in a tabular form. A comparative study with previous published results is also made.

Keywords

  • nanofluid
  • MHD
  • radiation
  • slip flow
  • stretching sheet
Open Access

Failure Analysis of Laminated Composite Plate Under Hygro-Thermo Mechanical Load and Optimisation

Published Online: 09 Aug 2019
Page range: 509 - 526

Abstract

Abstract

Failure analysis of laminated composite plates for different mechanical, thermo mechanical and hygro-thermo mechanical loads for different ply thicknesses, stacking sequences, fiber orientation angles and composite material systems is presented in the paper. A comparative study of different failure theories is also presented in the paper. The effect of fiber orientation angles on the first ply failure load is also studied. A hybrid composite laminate is developed based on the first ply failure load which minimizes weight and cost. The last ply failure load based on fully discounted method is calculated for different stacking sequences. An optimum composite material system and laminate layup is studied for a targeted strength ratio which minimizes weight.

Keywords

  • first ply failure load
  • last ply failure load
  • strength ratio
  • fiber orientation angle
  • hybrid composite
Open Access

Simultaneous Chemical Reactions Effect on Dispersion of a Solute in Peristaltic Propulsion of a Newtonian Fluid in an Inclined Channel with Wall Properties

Published Online: 09 Aug 2019
Page range: 527 - 538

Abstract

Abstract

In this paper, the dispersion of a solute in the peristaltic propulsion of an incompressible and viscous fluid through a permeable medium under the influence of wall properties with simultaneous homogeneous, heterogeneous chemical reactions in an inclined uniform channel has been studied. The issue is studied through conditions of Taylor’s limit and long wavelength hypothesis. The mean effective coefficient of scattering expression is computed and outcomes are interpreted physically through graphs.

Keywords

  • dispersion
  • inclined channel
  • viscous fluid
  • peristaltic propulsion
  • wall properties
Open Access

Electrically Conducting Flow through Exponential Power Law Fluid with Variable Thermal Conductivity

Published Online: 09 Aug 2019
Page range: 539 - 548

Abstract

Abstract

The problem of exponential law of steady, incompressible fluid flow in boundary layer and heat transfer are studied in an electrically conducting fluid over a semi-infinite vertical plate assuming the variable thermal conductivity in the presence of a uniform magnetic field. The governing system of equations including the continuity equation, momentum equation and energy equation have been transformed into nonlinear coupled ordinary differential equations using appropriate similarity variables. All the numerical and graphical solutions are obtained through the use of Maple software. The solutions are found to be dependent on three dimensionless parameters including the magnetic field parameter M, thermal conductivity parameter β and Prandtl number Pr. Representative velocity and temperature profiles are presented at various values of the governing parameters. The skin-friction coefficient and the rate of heat transfer are also calculated for different values of the parameters.

Keywords

  • MHD
  • similarity solution
  • variable properties
  • boundary layer flow
  • exponential law
Open Access

The Characterization of the Stress Fields Near a Crack Tip for a Compact Specimen for Elastic-Plastic Materials Dominated by the Plane Strain State

Published Online: 09 Aug 2019
Page range: 549 - 576

Abstract

Abstract

The paper presents a comprehensive analysis of the stress field near a crack tip for a compact specimen dominated by the plane strain state using the finite element method. The analysis also includes the calculation of some parameters of in-plane constraints, both for small and large strain assumptions. It discusses the influence of the material characteristic, relative crack length and external load for the stress field, and the in-plane constraint parameter. The approximation formulas for some in-plane constraint parameters are presented.

Keywords

  • fracture mechanics
  • C(T)
  • stress field
  • FEM
  • constraints
  • plane strain
  • plastic zone
  • crack
Open Access

MHD Slip Flow Past an Extending Surface with Third Type Boundary Condition and Thermal Radiation Effects

Published Online: 09 Aug 2019
Page range: 577 - 590

Abstract

Abstract

MHD slip flow past an extending surface with third type (convective) boundary condition and thermal radiation is analysed. The governing momentum and energy equations are converted into set of nonlinear ordinary differential equations using appropriate similarity transformations. The Fourth-Order Runge-Kutta shooting method is applied for obtaining the numerical solution of the resulting nonlinear ordinary differential equations. The numerical results for velocity and temperature distribution are found for different values of the vital parameters, namely: the magnetic interaction factor, slip factor, convective factor, Prandtl number and radiation factor and are presented graphically, and discussed.

Keywords

  • third type (convective) boundary condition
  • slip flow
  • thermal radiation
  • extending surface
Open Access

Trajectory Planning of the Humanoid Manipulator

Published Online: 09 Aug 2019
Page range: 591 - 602

Abstract

Abstract

The paper presents a method of planning a collision-free trajectory for a humanoid manipulator mounted on a rail system. The task of the robot is to move its end-effectors from the current position to the given final location in the workspace. The method is based on a redundancy resolution at the velocity level. In addition to this primary task, secondary objectives are also taken into account. The motion of the robot is planned in order to maximize a manipulability measure in purpose of avoiding manipulator singularities. State inequality constraints resulting from collision avoidance conditions are also considered. A computer example involving a humanoid manipulator operating in a three dimensional task space is also presented.

Keywords

  • humanoid manipulator
  • redundancy resolution
  • collision avoidance
  • manipulability measure
Open Access

Phase-Lag Effects in Skin Tissue During Transient Heating

Published Online: 09 Aug 2019
Page range: 603 - 623

Abstract

Abstract

A three-phase-lag (TPL) model is proposed to describe heat transfer in a finite domain skin tissue with temperature dependent metabolic heat generation. The Laplace transform method is applied to solve the problem. Three special types of heat flux are applied to the boundary of skin tissue for thermal therapeutic applications. The depth of tissue is influenced by the different oscillation heat flux. The comparison between the TPL and dual-phase-lag (DPL) models is analyzed and the effects of phase lag parameters (τq, τt and τv) and material (k*) on the tissue temperature distribution are presented graphically.

Keywords

  • bioheat transfer
  • skin tissue
  • three-phase-lag
  • Laplace transform
  • transient heating
Open Access

Generation of Surface Waves Due to Initial Axisymmetric Surface Disturbance in Water with a Porous Bottom

Published Online: 09 Aug 2019
Page range: 625 - 644

Abstract

Abstract

A two-dimensional Cauchy Poisson problem for water with a porous bottom generated by an axisymmetric initial surface disturbance is investigated here. The problem is formulated as an initial value problem for the velocity potential describing the motion in the fluid. The Laplace and Hankel transform techniques have been used in the mathematical analysis to obtain the form of the free surface in terms of a multiple infinite integral. This integral is then evaluated asymptotically by the method of stationary phase. The asymptotic form of the free surface is depicted graphically in a number of figures for different values of the porosity parameter and for different types of initial disturbances.

Keywords

  • axisymmetric surface disturbance
  • porous bottom
  • Laplace and Hankel transform
  • method of stationary phase
  • free surface depression
Open Access

The Effect of Slip Velocity on Unsteady Peristalsis MHD Blood Flow through a Constricted Artery Experiencing Body Acceleration

Published Online: 09 Aug 2019
Page range: 645 - 659

Abstract

Abstract

In this analysis, we present a theoretical study to examine the combined effect of both slip velocity and periodic body acceleration on an unsteady generalized non-Newtonian blood flow through a stenosed artery with permeable wall. A constant transverse magnetic field is applied on the peristaltic flow of blood, treating it as an elastico-viscous, electrically conducting and incompressible fluid. Appropriate transformation methods are adopted to solve the unsteady non-Newtonian axially symmetric momentum equation in the cylindrical polar coordinate system with suitably prescribed conditions. To validate the applicability of the proposed analysis, analytical expressions for the axial velocity, fluid acceleration, wall shear stress and volumetric flow rate are computed and for having an adequate insight to blood flow behavior through a stenosed artery, graphs have been plotted with varying values of flow variables, to analyse the influence of the axial velocity, wall shear stress and volumetric flow rate of streaming blood.

Keywords

  • elastico-viscous
  • slip velocity
  • selective permeability
  • peristalsis
  • stenosed artery

MSC 2010

  • 76Zxx
  • 76Wxx
Open Access

On Propagation of Rayleigh Type Surface Wave in Five Different Theories of Thermoelasticity

Published Online: 09 Aug 2019
Page range: 661 - 673

Abstract

Abstract

The governing equations for a homogeneous and isotropic thermoelastic medium are formulated in the context of coupled thermoelasticity, Lord and Shulman theory of generalized thermoelasticity with one relaxation time, Green and Lindsay theory of generalized thermoelasticity with two relaxation times, Green and Nagdhi theory of thermoelasticity without energy dissipation and Chandrasekharaiah and Tzou theory of thermoelasticity. These governing equations are solved to obtain general surface wave solutions. The particular solutions in a half-space are obtained with the help of appropriate radiation conditions. The two types of boundaries at athe surface of a half-space are considered namely, the stress free thermally insulated boundary and stress free isothermal boundary. The particular solutions obtained in a half-space satisfy the relevant boundary conditions at the free surface of the half-space and a frequency equation for the Rayleigh wave speed is obtained for both thermally insulated and isothermal cases. The non-dimensional Rayleigh wave speed is computed for aluminium metal to observe the effects of frequency, thermal relaxation time and different theories of thermoelasticity.

Keywords

  • generalized thermoelasticity
  • surface waves
  • Rayleigh wave
  • frequency equation
Open Access

Radiation Absorption and Chemical Reaction Effects on Rivlin-Ericksen Flow Past a Vertical Moving Porous Plate

Published Online: 09 Aug 2019
Page range: 675 - 689

Abstract

Abstract

An analysis has been carried out to study the combined effects of radiation absorption and chemical reaction on an incompressible, electrically conducting and radiating flow of a Rivlin-Ericksen fluid along a semi-infinite vertical permeable moving plate in the presence of a transverse applied magnetic field. It is assumed that the suction velocity, the temperature and the concentration at the wall are exponentially varying with time. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. A comparison is made with the available results in the literature for a special case and our results are in very good agreement with the known results. A parametric study of the physical parameters is made and results are presented through graphs and tables. The results indicate that the fluid velocity and temperature could be controlled by varying the radiation absorption.

Keywords

  • Rivlin-Ericksen fluid
  • radiation absorption
  • chemical reaction
  • variable temperature
  • concentration and suction
Open Access

Plane Waves in Thermo-Viscoelastic Material with Voids Under Different Theories of Thermoelasticity

Published Online: 09 Aug 2019
Page range: 691 - 708

Abstract

Abstract

Propagation of time harmonic plane waves in an infinite thermo-viscoelastic material with voids has been investigated within the context of different theories of thermoelasticity. The equations of motion developed by Iesan [1] have been extended to incorporate the Lord-Shulman theory (LST) and Green-Lindsay theory (GLT) of thermoelasticity. It has been shown that there exist three coupled dilatational waves and an uncoupled shear wave propagating with distinct speeds. The presence of thermal, viscosity and voids parameters is responsible for the coupling among dilatational waves. All the existing waves are found to be dispersive and attenuated in nature. The phase speeds and attenuation coefficients of propagating waves are computed numerically for a copper material and compared under different theories of thermo-elasticity. The expressions of energies carried along each wave have also been derived. All the computed numerical results have been depicted through graphs. It is found that the influence of CT and GLT is almost same on wave propagation, while LST influences the wave propagation differently.

Keywords

  • thermo-visco-elasticity
  • voids
  • waves
  • phase speed
  • attenuation
  • energy
Open Access

Unsteady Three-Dimensional MHD Nanofluid Flow Over a Stretching Sheet with Variable Wall Thickness and Slip Effects

Published Online: 09 Aug 2019
Page range: 709 - 724

Abstract

Abstract

The stretching sheets with variable thickness may occur in engineering applications more frequently than a flat sheet. Due to its various applications, in the present analysis we considered a three dimensional unsteady MHD nanofluid flow over a stretching sheet with a variable wall thickness in a porous medium. The effects of radiation, viscous dissipation and slip boundary conditions are considered. Buongiorno’s model is incorporated to study the combined effects of thermophoresis and Brownian motion. The dimensionless governing equations are solved by using MATLAB bvp4c package. The impact of various important flow parameters is presented and analysed through graphs and tables. It is interesting to note that all the three boundary layer thicknesses are diminished by slip parameters. Further, the unsteady parameter decreases the hydromagnetic boundary layer thickness.

Keywords

  • unsteady flow
  • magnetic field
  • Buongiorno’s model
  • variable wall thickness sheet
  • velocity
  • thermal and solutal slip
Open Access

Thermal Radiation, Chemical Reaction, Viscous and Joule Dissipation Effects on MHD Flow Embedded in a Porous Medium

Published Online: 09 Aug 2019
Page range: 725 - 737

Abstract

Abstract

An analysis is presented to study the effects of thermal radiation, chemical reaction, viscous and Joule dissipation on MHD free convection flow between a pair of infinite vertical Couette channel walls embedded in a porous medium. The fluid flows by a strong transverse magnetic field imposed perpendicularly to the channel wall on the assumption of a small magnetic Reynolds number. The governing non linear partial differential equations are transformed in to ordinary differential equations and are solved analytically. The effect of various parameters viz., Eckert number, electric conductivity, dynamic viscosity and strength of magnetic field on temperature profile has been discussed and presented graphically.

Keywords

  • thermal radiation
  • chemical reaction
  • Joule dissipation
  • viscous dissipation
  • porous medium

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