Heat and mass transfer effects on the peristaltic flow of Johnson–Segalman fluid in a curved channel with compliant walls

The influence of heat and mass transfer has been carried out in the peristaltic transport of Johnson–Segalman fluid in a curved channel with flexible walls. The relevant flow problem is modeled. The solution analysis is given under long wavelength and low Reynolds number approximations. Expressions for stream function, temperature and concentration fields are derived. The effects of emerging parameters in the obtained solutions are plotted and analyzed.     

Heat transfer analysis of peristaltic flow in a curved channel

We investigate the effects of heat transfer on peristaltic flow of a viscous fluid in a curved channel. Governing equations for flow and heat transfer are derived using long wavelength and small Reynolds number assumptions. Exact solution is obtained for stream function. The temperature field is obtained numerically by a shooting method using Runge–Kutta algorithm. Effects of curvature parameter and Brinkman number are analyzed on various features of peristaltic motion and temperature field. It is found that peristaltic pumping rate increases in going from straight to curved channel. It is further noted that the symmetry of trapped bolus is destroyed in the curved channel and upper bolus pushes the lower bolus toward the lower wall. Moreover, the rate of heat transfer decreases in a curved channel in comparison with the case of straight channel.     

Mixed convective heat and mass transfer on a peristaltic flow of a non‐Newtonian fluid in a vertical asymmetric channel

In the present analysis we discuss the effects of mixed convective heat and mass transfer on the peristaltic flow of a non‐Newtonian fluid in a vertical asymmetric channel. The flow is investigated in a wave frame of reference moving with the velocity c away from the fixed frame. The governing equations for the present flow problem are first modeled and then discussed. The analytical solution of the present flow problem is discussed using regular perturbation technique. The graphical results are discussed to see the effects of various physical parameters of interest. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21020     

Effect of wall properties on the peristaltic flow of a third grade fluid in a curved channel with heat and mass transfer

Analysis has been carried out to study the heat and mass transfer effects on the peristaltic flow in a curved channel with compliant walls. Firstly, mathematical modelling is performed and then solution is obtained under the assumptions of long wavelength and low Reynolds number. Stream function, temperature and concentration fields are derived. The effects of emerging parameters in the obtained solutions are discussed.     

Theory of transient multicomponent transport coupling in three-dimensional stagnation flows

A general field transformation for transient three-dimensional multicomponent energy and species equations is presented. Employing this transformation, transient multicomponent transport coupling effects in three-dimensional flows with surface injection cooling are studied. A new multicomponent transport coupling parameter is introduced and new results for the surface heat flux for various values (between 0 and 1) of this parameter are given. These values of the transport coupling parameter represent a wide range of transport properties of multicomponent mixtures. The present results demonstrate how a given final surface cooling efficiency can be obtained by choosing a variety of combinations of various values of the transport coupling parameter and injection rates. The present study also reveals an interesting behavior of local overshoot values in the transient relative contribution of the transport coupling effects to the surface heat flux. This behavior is explained here in terms of fluctuations in a multicomponent 'Transport-coupling Activity' number, which is sensitive to the differences in the characteristic rate of change of the local concentration gradients with respect to the local temperature gradient.     

Influence of magnetic field and thermal radiation on peristaltic motion with double‐diffusive convection in Jeffery nanofluids

A theoretical study is conducted to examine the peristaltic pumping with double‐diffusive convection in Jeffery nanofluids through a two‐dimensional infinite asymmetric channel. The flow is examined in a wave casing of orientation that moves pace with the velocity of the wave. The peristaltic wave train on the walls that have different amplitude and phase is chosen to form channel irregularity. Rosseland approximation is noticed in the modeling of the transmission radiation heat transfer and temperatures of the walls are recognized constants. The replica has a great impact in discovering nanofluid dynamic influences on peristaltic motion, in biological vessels as symbolized by transportation of heat in blood flow, food molecules, hormones, novel pharmacodynamics pumps, and engineered gastrointestinal motility enhancement. Peristaltic motion has applications in physiology, such as transport of urine, transport of food bolus through gastrointestinal tract, and transport of blood through small blood vessels. Analytical results have been established for stream function, axial velocity, temperature, and absorption and nanoparticle volume fraction. The effect of the principal hydrodynamic parameters (thermophoresis, Brownian motion, Dufour, and Soret) and Grashof numbers (concentration, thermal, nanoparticle) on peristaltic transport patterns with double‐diffusive convection are deliberated with the support of computational outcomes found. The pictorial investigation is done to investigate the possessions of miscellaneous limitations on flow quantities of curiosity.     

Peristaltic flow of Buongiorno model nanofluids within a sinusoidal wall surface used in drug delivery

The current paper deals with the radiative heat transfer of the peristaltic flow of the Buongiorno model nanofluid through a two‐dimensional channel with a sinusoidal wall surface. A particular form of fluid transport occurring through progressive wave of expansion or contraction generating along a distensible tube containing fluid is known as peristaltic pumping, which takes place from the lower pressure region to the higher pressure region. Peristaltic transport finds several applications, such as blood pumping in heart, lung, and pharmacological delivery systems, and industrial applications—sanitary fluid transport, corrosive fluids transport, and so on. An approximate analytical solution is employed for the solution of the system of transformed differential equations with prescribed boundary conditions. The influences of physical parameters characterizing the flow phenomena are obtained and presented via graphs. The result warrants a good correlation with earlier studies in particular case. The following are the main findings: thermophoresis is favorable to enhance the fluid temperature near the channel center and also the axial velocity increases as an increase in the thermal buoyancy parameter. However, the main findings are elaborated in Section 3.     

Marangoni effects on the boiling of 2-propanol/water mixtures in a confined space

In this study, boiling experiments were conducted with 2-propanol/water mixtures in a confined gap under various gravity levels to examine the Marangoni effects on near-bubble microscale transport. Full boiling curves were obtained and two boiling regimes determined--nucleate and pseudo film boiling. The transition condition and the critical heat flux were also identified. Relative to pool boiling, the gap geometry caused lower CHF values, and deteriorated heat transfer at high superheated temperatures. This influence was particularly significant when greater Marangoni forces were present under reduced gravity conditions. The results of this study demonstrate the complex interaction that these three factors--Marangoni force, gravity level, and gap size--have on heat transfer.     

The effects of Joule heating and variable thermal conductivity on peristaltic pumping of Jeffrey nanofluid in the presence of heat transfer

This investigation aims to study Hall's current effect on the peristaltic flow of a Jeffrey nanofluid with variable thermal conductivity in an inclined asymmetric channel. Joule heating and oblique magnetic field effects are taken into consideration. A system of ordinary differential equations is obtained under the approximation of low Reynolds number and long wavelength, which consists of momentum, energy, and concentration equations. The influences of penitent physical parameters on the distribution of velocity, temperature, and concentration have been discussed graphically. Streamline graphs are offered in the terminus, which elucidates the trapping bolus phenomenon. The resulting equations are solved numerically using the ND Solver technique. The thermal conductivity parameter causes the pressure gradient to increase while reducing the pressure rise. Our present model can be applied to physiological flow transportation in the veins with heat transfer.     

Influence of elasticity in an inclined annulus of nanofluid with peristaltic transport

Peristaltic transport of Newtonian nanofluid in an inclined annulus terms of radii regarding peristalsis and elasticity. It is noticed that with an increase in amplitude ratio, flux is getting enhanced in the absence of nanoparticles when compared with viscous fluid with nanoparticles. Our results reduce to the corresponding ones of Rubinow and Keller as a special case for the viscous flow in an elastic tube. The effect of various emerging parameters bounded by two concentric cylinders is studied under the assumption of long wavelength and dominance of viscous effects over inertial effects. The outer cylinder is elastic in nature and has a sinusoidal wave traveling down in its wall, whereas the inner cylinder is rigid. Analytical solutions have been established for velocity, flux, pressure rise, temperature distribution, and nanoparticle concentration. The flux, pressure rise, and frictional forces have been obtained in on the flow characteristic are presented and discussed. Obtained results may be useful in understanding the behavior of peristaltic transport of blood flow in small blood vessels and blood flow through elastic arteries.     

Peristaltic flow of a Williamson fluid in an inclined asymmetric channel with partial slip and heat transfer

The present article deals with the peristaltic flow of a Williamson fluid in an inclined asymmetric channel. The relevant equations have been modeled. Analysis has been carried out in the presence of velocity and thermal slip conditions. Expressions for stream function, temperature, pressure gradient and heat transfer coefficients are derived. The solutions are compared with the existing available results in a limiting sense. Numerical integration has been performed for pressure rise per wavelength. Plots are presented and analyzed for various embedded parameters into the problem. Comparison between the solutions is also shown.     

Analysis of thermal radiation,Joule heating,and viscous dissipation effects on blood-gold couple stress nanofluid flow driven by electroosmosis

Gold nanoparticles associated with DNA, RNA, proteins, oligonucleotides, and peptides are useful in therapies and drug delivery. The present article mainatins that gold nanoparticles play a tremendous role in remedying cancer and fatal diseases. A mathematical model is proposed for the two-dimensional motion of the couple stress nanofluid consisting of gold nanoparticles under the application of peristaltic propulsion and electroosmosis mechanisms in an asymmetric microchannel. The effects of radiation with slip boundary have been employed. The governing equations are simplified under the assumptions of low Reynolds number and long wavelength and the Poisson-Boltzmann equation is solved under Debye–Hückel linearization. Analytical solutions for the velocity of fluid motion, nanoparticle temperature, stream function, pressure gradient, are evaluated and analyzed graphically under the effects of various physical parameters. It is notable from the analysis that raising the Brinkman number boosts the nanoparticle temperature and heat transfer coefficient which validate the physical model and analysis. Moreover, it is noticed that sphere-shaped gold nanoparticles enhance the temperature as compared to other geometries of nanoparticles. The present study results may assist in developing the technology, smart micropumps, drugs, and device for hemodialysis and other health care applications.     

SPECIALLY TAILORED TRANS FINITE-ELEMENT FORMULATIONS FOR HYPERBOLIC HEAT CONDUCTION INVOLVING NON-FOURIER EFFECTS

The phenomenon of hyperbolic heat conduction in contrast to the classical (parabolic) form of Fourier heat conduction involves thermal energy transport that propagates only at finite speeds as opposed to an infinite speed of thermal energy transport. To accommodate the finite speed of thermal wave propagation, a more precise form of heat flux law is involved, thereby modifying the heat flux originally postulated in the classical theory of heat conduction. As a consequence, for hyperbolic heat conduction problems, the thermal energy propagates with very sharp discontinuities at the wave front. The primary purpose of the present paper is to provide accurate solutions to a class of one-dimensional hyperbolic heat conduction problems involving non-Fourier effects that can precisely help understand the true response and furthermore can be used effectively for representative benchmark tests and for validating alternate schemes. As a consequence, the present paper purposely describes modeling/analysis formulations via specially tailored hybrid computations for accurately modeling the sharp discontinuities of the propagating thermal wave front. Comparative numerical test models are presented for various hyperbolic heat conduction models involving non-Fourier effects to demonstrate the present formulations.     

Analytical and experimental investigation on the operational characteristics and the thermal optimization of a miniature heat pipe with a grooved wick structure

A mathematical model for heat and mass transfer in a miniature heat pipe with a grooved wick structure is developed and solved analytically to yield the maximum heat transport rate and the overall thermal resistance under steady-state conditions. The effects of the liquid-vapor interfacial shear stress, the contact angle, and the amount of initial liquid charge have been considered in the proposed model. In particular, a novel method called a modified Shah method is suggested and validated; this method is an essential feature of the proposed model and accounts for the effect of the liquid-vapor interfacial shear stress. In order to verify the model, experiments for measuring the maximum heat transport rate and the overall thermal resistance are conducted. The analytical results for the maximum heat transport rate and the total thermal resistance based on the proposed model are shown to be in close agreement with the experimental results. From the proposed model, numerical optimization is performed to enhance the thermal performance of the miniature heat pipe. It is estimated that the maximum heat transport rate of outer diameter 3 and 4 mm heat pipes can be enhanced up to 48% and 73%, respectively, when the groove wick structure is optimized from the existing configurations. Similarly, the total thermal resistance of these heat pipes can be reduced by 7% and 11%, respectively, as a result of optimization.     

Peristaltic transport of viscous fluid in a curved channel with compliant walls

Influence of compliant wall properties and heat transfer on the peristaltic flow of an incompressible viscous fluid in a curved channel is discussed. Long wavelength and low Reynolds number approach has been employed and the expressions of stream function, velocity and temperature profiles are derived. The variations of various interesting parameters are shown and examined very carefully.     

Sharp-interface simulation of dendritic solidification of solutions

A numerical method is developed for the simulation of solidification of solutions/alloys. The heat and species transport equations are solved with appropriate interface conditions. The interface shape and thermal and solutal fields are calculated in a fully coupled manner. The effects of capillarity are included in the interfacial dynamics. The present mixed Eulerian-Lagrangian framework treats the immersed phase boundary as a sharp solid-fluid interface and a conservative finite-volume formulation allows boundary conditions at the moving surface to be exactly applied. We first compare the planar growth results with published one-dimensional numerical results. We then show that the method can compute the breakdown of the solid-liquid interface due to the Mullins-Sekerka instability. The dendritic growth of the crystals under various growth parameters is computed.     

Influence of the induced magnetic field and heat transfer on peristaltic transport of a micropolar fluid in a tapered asymmetric channel

In this paper, we investigate the peristaltic transport of a micropolar fluid in a tapered asymmetric channel with heat transfer and induced magnetic field effect. The flow is analyzed by long wavelength and low Reynolds number approximations. The reduced equations have been solved by using Adomian decomposition method and the expressions for velocity, stream function, microrotation component, magnetic‐force function, pressure gradient, axial induced magnetic field, and current density distribution across the channel have been computed. Expressions for shear stresses are also obtained. The effect of pertinent parameters is illustrated graphically.     

Entropy and exergy analysis on peristaltic pumping in a curved narrow channel

A mathematical model is presented to study the thermal characteristics in terms of entropy generation rate and thermodynamic potential of improvement for peristaltic pumping of a viscous fluid in a curved channel. Radial magnetic field effect is also taken into account. Avoidable and unavoidable exergy destruction concepts are further utilized. Computations of the entropy generation rate are evaluated in terms of stream function and temperature field. Avoidable exergy destruction is computed through entropy function and its minimum value. Impacts of parameters like the curvature ratio, Hartmann number, and viscous dissipation parameters on the average entropy generation rate, Bejan number, and avoidable exergy destruction are analyzed through graphs. Contours for the temperature field and entropy generation are also illustrated to examine the effects of curvature effects on thermal characteristics. Computed results indicate that the curvature of the channel and magnetic strength strongly influence the sources of entropy generation rate and avoidable exergy destruction. The observations demonstrate promising features of the bioinspired peristaltic pumping that can be utilized in various thermal systems.     

Peristaltic flow under the effects of an induced magnetic field and heat and mass transfer

Influence of heat and mass transfer on the peristaltic flow of pseudoplastic fluid in the presence of an induced magnetic field has been considered. The fluid is considered in a channel with non-conducting walls. Analysis have been made out under the assumptions of long wavelength and low Reynolds number. Series solution for the stream function, pressure gradient, magnetic force function, temperature and concentration distributions have been computed. The flow quantities have been examined for various interesting parameters. The pressure rise and heat transfer coefficient are also analyzed.     

Study on heat transport rate of an osmotic heat pipe: III. Estimation of heat transport limits

This paper describes an experimental and theoretical study on the heat transport limits of an osmotic heat pipe operated under atmospheric pressure, using an aqueous solution of polyethylene glycol 600 (0.1 to 1.0 kmol/m³) as the working fluid and 18 tubular‐type acetyl cellulose osmotic membranes. The correlation between the heat transport rate and the effective osmotic area is clarified. Also, the effects of the physical properties of the solution and the geometry of the osmotic heat pipe (e.g., inside diameters of flow lines) on the heat transport rate are theoretically examined. The heat transport rate of the present osmotic heat pipe is found to be about 85% compared with that under an ideal condition such that the solution circulation flow rate is very large, that is, the average concentration in a membrane module is equal to that in the solution loop. © 2000 Scripta Technica, Heat Trans Asian Res, 29(7): 559–572, 2000