Biomimetic designs are increasingly filtering into new areas of technology in recent years. Such systems exploit characteristics intrinsic to nature to achieve enhanced adaptivity and efficiency in engineering applications. Peristaltic propulsion is an example of such characteristics and in the current article it is explored as a feasible mechanism for deployment in electrokinetic pumping of nanofluids through a curved distensible conduit as a model for a bioinspired smart device. The unsteady mass, momentum, energy and nanoparticle concentration conservation equations for a Newtonian aqueous ionic fluid under an axial electrical field are formulated and simplified using lubrication approximations and low zeta potential (Debye Huckel linearization). A dilute nanofluid is assumed with Brownian motion and thermophoretic body forces present. The reduced non-dimensional conservation equations are solved with the symbolic software, Mathematica 9 via the NDSolve algorithm for velocity, temperature, nano-particle concentration distributions for low zeta potential. An entropy generation analysis is also conducted. The influence of curvature parameter, maximum electroosmotic velocity (Helmholtz-Smoluchowski velocity), inverse EDL thickness parameter, zeta potential ratio and Joule heating parameter on transport characteristics is evaluated with the aid of graphs and contour plots. Temperature profiles are elevated with positive Joule heating and reduced with negative Joule heating whereas the opposite behaviour is observed for the nano-particle concentrations.

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Analysis of entropy generation in biomimetic electroosmotic nanofluid pumping through a curved channel with joule dissipation

Abstract This paper investigates the propagation of Rayleigh surface waves in a rotating semi-infinite solid medium, permeated by an initial magnetic field in the context of linear nonlocal elasticity. Frequency equations are derived and the combined effect of magnetic field and rotation on Rayleigh wave propagation, based on the linear theory of nonlocal elasticity has been studied. Effects of magnetic field, as well as rotation on Rayleigh wave propagation in a nonlocal medium, have also been analyzed in details as special cases. Numerical calculations, graphs and discussions presented in this paper lead us to some important conclusions. Fourier double integral transform technique has been applied to solve the problem.

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Rayleigh Wave In A Rotating Nonlocal Magnetoelastic Half-Plane*

It may not be enough to hold all the engineering problems by the supposition that material mediums are isotropic, homogeneous, without initial stress and have a planar boundary surface, as the concept cannot indulge many features of the continuum response which are of great significance. This motivates us to study the influence of corrugated boundary surfaces, reinforcement, hydrostatic stress, heterogeneity and anisotropy on the propagation of Love-type wave in a corrugated heterogeneous orthotropic layer lying over a fibre-reinforced half-space under hydrostatic state of stress. The heterogeneity in the upper corrugated layer is caused due to exponential variation in the elastic constants with respect to the space variable pointing positively downwards. The dispersion relation has been obtained in closed form and found in well-agreement to the classical Love wave equation. The substantial effect of corrugation parameters, reinforcement, undulatory parameter, hydrostatic state of stress, heterogeneity parameter, position parameter and wave number on the phase velocity of Love-type wave has been observed and depicted by means of graph. The comparative study to unravel the effect of presence and absence of corrugated boundary surfaces of layer, heterogeneity in upper layer, reinforcement in half-space and anisotropy existing in both layer and half-space, on the dispersion curve is among the important peculiarities of the present paper.

Influence of corrugated boundary surfaces, reinforcement, hydrostatic stress, heterogeneity and anisotropy on Love-type wave propagation

The present investigation is concerned with the reflection of plane waves at the free surface of a homogeneous, isotropic, nonlocal, micropolar rotating thermoelastic medium. The entire thermoelastic medium is rotating with a uniform angular velocity. It is observed that there exist four coupled plane waves, which travel through the medium with distinct speeds. Using appropriate boundary conditions, the reflection coefficients and energy ratios of various reflected waves are computed numerically with the help of the software MATLAB. The numerical values of modulus of reflection coefficients are presented graphically to show the effects of nonlocal, rotation and micropolar parameters. It has been verified that during reflection phenomena, the sum of modulus of energy ratios is approximately equal to unity at each angle of incidence. The effect of micropolarity on the phase velocities is also observed and shown graphically.

Reflection of plane waves in a nonlocal micropolar thermoelastic medium under the effect of rotation

The paper primarily aims to examine the fractional effect and explore the impact of temperature-dependent properties and primary stress on reflecting plane and secondary vertically waves using the three-phase-lag model (THPL). Its problem has been formulated by neglecting the body force and external heat source and having initial stress and temperature-dependent under THPL theory in its fractional form (conformable fractional derivatives). The boundary conditions were applied taking into account mechanical stresses and temperature-dependence. A comparison between analytical and fractional solutions for the problem was made to get the solution included in the fractional orders. The authors analyzed the findings. They presented the findings graphically to illustrate the physical meaning of the issue under study. If the problem considered is in integer form, we strongly included that the results obtained agree with the results obtained by Abo-Dahab et al. (2020).

Fractional derivative order analysis and temperature-dependent properties on p- and SV-waves reflection under initial stress and three-phase-lag model

Reflection of Plane Waves in a Rotating Transversly Isotropic Magneto-Thermoelastic Solid Half-Space The governing equations of a rotating transversely isotropic magneto-thermoelastic medium are solved to obtain the velocity equation, which indicates the existence of three quasi plane waves. Reflection of these plane waves from a stress-free thermally insulated surface is studied to obtain the reflection coefficients of various reflected waves. The effects of anisotropy, rotation, thermal and magnetic fields are shown graphically on these coefficients.

Reflection of Plane Waves in a Rotating Transversly Isotropic Magneto-Thermoelastic Solid Half-Space

The governing equations for a rotating monoclinic magnetothermoelastic medium are formulated in the context of the Lord–Shulman theory and are solved to yield the velocity equation that points to the existence of three quasiplane waves. Some particular cases are obtained, i.e., waves in the absence of anisotropy, rotation, and thermal and magnetic fields. A procedure for computing the angles of reflection is carried out. A numerical example is considered to show the dependence of the speeds of various plane waves on the angle of incidence, angle of reflection, rotation rate, and magnetic field strength.

Plane Waves in a Rotating Monoclinic Magnetothermoelastic Medium

This research article deals with the propagation of plane waves in a rotating magneto-thermoelastic half-space with diffusion in the context of Lord–Shulman theory of thermoelasticity. The governing equations are formulated for a specialized plane and solved to obtain the velocity equation, which indicates the existence of four coupled plane waves. The wave velocities are computed for a particular medium, and the effect of the diffusion parameter is shown graphically on these waves. Impedance boundary conditions are applied to study the reflection of plane waves from the stress-free and thermally insulated/isothermal surface. Reflection coefficients and energy ratios of the reflected waves are also obtained, and the variations of reflection coefficients and energy ratios against the angle of incidence are shown graphically.

Anand Kumar Yadav

Papers

Reflection of Plane Waves in a Rotating Transversly Isotropic Magneto-Thermoelastic Solid Half-Space

Plane Waves in a Rotating Monoclinic Magnetothermoelastic Medium

Effect of impedance on the reflection of plane waves in a rotating magneto-thermoelastic solid half-space with diffusion

Thermoelastic waves in a fractional-order initially stressed micropolar diffusive porous medium

Reflection of plane waves from a micropolar thermoelastic solid half-space with impedance boundary conditions