Suspensions Of Particles In Fluid Research Articles

Particle–Fluid Suspension of a Non-Newtonian Fluid Through a Curved Passage: An Application of Urinary Tract Infections

The current investigation deals with the inclusion of solid particles in the flow of a non-Newtonian incompressible fluid passing through a symmetric curved channel admitting flexible walls and exhibiting wavy characteristics for the passage of fluid. This analysis reflects the disease of white particles occurring in the flow of urine. The problem formulation is structured under the constraints of lubrication approach. The flow is considered to be laminar and steady by transforming the unsteady coordinates into wave frame coordinates. The governing equations have been formulated with the help of similarity transformations. The solution of boundary value problems has been handled by perturbation procedure. The analytical solution for fluid and particulate phase velocities, mean flow rates and pressure gradient profile has been presented while a numerical treatment have been carried out for pressure rise. Analysis of fluid velocity and particulate suspension velocity, pressure gradient and pressure rise curves under the variations of material parameters has been discussed by graphs. It is observed from this persual that solid particles are curtailing the velocity and pressure of the liquid. It is also procured that the curvature of the channel also reduces the movement of the fluid and particulate suspension is occurring at the bottom of the container. It is very considerable that the increase in peristaltic pumping causes a decrease in the solid particle concentration. This theoretical analysis can help in curing the diseases like Urinary tract infections (UTIs).

MHD Flow and Nonlinear Thermal Radiative Heat Transfer of Dusty Prandtl Fluid over a Stretching Sheet

Boundary layer flows and melting heat transfer of a Prandtl fluid over a stretching surface in the presence of fluid particle suspensions has been investigated. The converted set of boundary layer equations are solved num... | Find, read and cite all the research you need on Tech Science Press

Magnetized peristaltic particle–fluid propulsion with Hall and ion slip effects through a permeable channel

In this article, combine impacts of the Hall and ion slip with heat exchange on the peristaltic movement of MHD particle–fluid suspension through a permeable channel have been examined. The representing flow issue for the liquid stage and dusty stage have been displayed with the assistance of long wavelength and disregarding the inertial forces. Correct arrangements are gotten for velocity and temperature profile. The effect of all the applicable parameters, for example, particle volume fraction, Hartmann number, ion slip parameter, Hall parameter, Darcy number, Prandtl number, Eckert number, are portrayed for velocity and temperature profile. It is observed that the velocity profile appears inverse close to the qualities for bigger estimations of the Darcy parameter, however, it diminishes because of Hartmann number and particle volume fraction. Moreover, the behavior of velocity profile stays comparative for hall and ion slip parameter. The Darcy parameter also shows significant resistance to the temperature profile.

Numerical study of heat transfer and Hall current impact on peristaltic propulsion of particle-fluid suspension with compliant wall properties

In this paper, the effects of heat transfer and Hall current on the sinusoidal motion of solid particles through a planar channel has been discussed. The walls of the channel are considered as compliant under the effects of magnetohydrodynamics. The mathematical formulation has been performed using energy equation, momentum equation, and Ohm’s law. The modeled equations are further modified by taking the assumption of a zero Reynolds number and long wavelength. Numerical shooting technique has been employed to solve the nonlinear differential equations. The impact of all the emerging parameters such as wall rigidity, wall tension, mass characterization, Hall parameter, Hartmann number, Weissenberg number, particle volume fraction, Prandtl number, and Eckert number, respectively. Particularly, we discussed their effects on velocity and temperature profile.

Radial patterns and velocity field of non-Brownian suspensions in a fully filled horizontal rotating cylinder

This work reports radial patterns and velocity profiles of fluid-particle suspensions rotating in a fully filled horizontal cylinder using the technique of Particle Image Velocimetry. Dilute and mono-dispersed suspensions of non-Brownian settling as well as floating particles were considered. An analysis of the effect of particle shape on the flow patterns is provided. This was carried out by comparing the suspensions of spherical and cylindrical particles. Impact of particle shape on the particle-fluid interaction in determining the flow structure is more pronounced at lower speeds. Analysis of the velocity profiles showed a resemblance of the buoyant and settling suspensions phases. Despite the similar features observed, a difference was noted when the centrifugal forces dominate. Our experimental results are in good qualitative agreement with the previous experiments and simulations. Through a detailed investigation of velocity field we have established the strong relationship between the phase transition and rotational speed.

Entropy hemodynamics particle-fluid suspension model through eccentric catheterization for time-variant stenotic arterial wall: Catheter injection

Catheterization has an imperative rule in heat transfer investigations, which are frequently applied to analyze and deal with the heart transfer studies. Here, the entering of a catheter adjusts the flow of the blood and it affects the hemodynamic status in the artery region. In practical clinical cases, catheters cannot be precisely concentric with the artery. The impartial of this work is to investigate the behavior of a blood streaming characteristics, in the case of injecting the catheter eccentrically all the way through a stenotic overlapping artery. In this paper, we consider the heat transfer within the presence of blood corpuscle which has been characterized by a macroscopic two-phase model (i.e. a suspension of erythrocytes in plasma). The model here considers the blood fluid as a liquid fluid with adjourned particles in the gap bounded by the eccentric cylinder. The inside cylinder is identically rigid demonstrating the movable thin catheter and kept at constant temperature, where the outer cylinder is a taper cylinder demonstrating the artery that has overlapping stenosis and it is cooled and maintained at zero temperature. The coupled differential equations for both fluid (plasma) and particle (erythrocyte) phases have been solved. The expressions for the flow characteristics, namely, the flow rate, the impedance (resistance to flow), the wall shear stress and the temperature distribution, have been derived. The model is very useful in medicine, where the hemodynamic speed is higher for eccentric case than that of concentric one. Also, the temperature distribution and the entropy generation in the state of eccentric position are higher than in the case of the concentric position. A significant increase in the magnitude of the impedance and the wall shear stress occurs for an increase in the hematocrit, C for diseased blood.

Velocity Profile of Fluid Particle Suspension over a Horizontal Plate with Electrification of Particles

The modelling of electrified flow over a horizontal plate is considered. Here the fluid is of Newtonian type and fluid-fluid, fluid- particles collisions are accounted. The effective volumetric force, viscous dissipation, browanion diffusion, in fluid phase as well as particle phase has been considered. In this paper we considered the generation of electricity due to hitting of particles with each other and with the wall of the flow and its impact on motion of flow particles. The systems of equations representing the flow are solved by finite difference method. It concludes from outcome of computation that the particle velocity rises with rise of electricity generation and increasing size of particles.

Effects of slip conditions and compressibility on the peristaltic flow of particulate suspension in a planar channel

This paper concerns with the peristaltic flow of a particle–fluid suspension (as blood model) through asymmetric two-dimensional channel with slip conditions. The problem formulation is presented for a duct filled with a compressible viscous fluid mixed with rigid spherical particles. The resulting problems are solved by the perturbation expansion method. The effects of different physical parameters such as particles concentration, compressibility parameter, and slip parameter have a significant effect on velocity distributions and are presented and discussed graphically. It is found that the mean axial velocity increases as the slip parameter increases at a minimal compressibility parameter, and it decreases at a higher value of compressibility parameter with increasing slip parameter. This paper gives a scope for estimating the effects of the slip conditions of two-phase flow characteristics with compressible fluid problems and helps in understanding the role of the engineering applications of pumping solid–fluid mixture by peristaltically driven motion.

Metachronal propulsion of a magnetised particle-fluid suspension in a ciliated channel with heat and mass transfer

Biologically-inspired pumping systems are of great interest in modern engineering since they achieve enhanced efficiency and circumvent the need for moving parts and maintenance. Industrial applications also often feature two-phase flows. In this article, motivated by these applications, the pumping of an electrically-conducting particle-fluid suspension due to metachronal wave propulsion of beating cilia in a two-dimensional channel with heat and mass transfer under a transverse magnetic field is investigated theoretically. The governing equations for mass and momentum conservation for fluid- and particle-phases are formulated by ignoring the inertial forces and invoking the long wavelength approximation. The Jeffrey viscoelastic model is employed to simulate non-Newtonian characteristics. The normalised resulting differential equations are solved analytically. Symbolic software is employed to evaluate the results and simulate the influence of different parameters on flow characteristics. Results are visualised graphically with carefully selected and viable data. With increasing wave number (β) fluid velocity is accelerated in the core region whereas it is decelerated near the channel wall, for the Newtonian case. With increasing eccentricity of cilia elliptic path (α), a similar response is computed as for the wave number. The size of the bolus is enhanced (and quantity of boluses is reduced) with increasing eccentricity of the cilia elliptic path (α) and Hartmann (magnetic) number (M) whereas bolus size is decreased (and quantity of boluses is increased) with increasing wave number (β) and particle volume fraction (C). It is also noted that increasing Schmidt number (Sc) and Soret number (Sr) diminish the concentration magnitudes. Furthermore, Brinkman number (which represents viscous heating effects) significantly boosts the temperature magnitudes. The current analysis provides a useful benchmark for more general computational simulations.

Viscoelastic properties of suspensions of noncolloidal hard spheres in a molten polymer

We report an experimental study on suspensions of solid particles in a viscoelastic polymer matrix. A commercial entangled poly(ε-caprolactone) was used as the suspending fluid. Noncolloidal solid spheres (diameter = 15 μm) made of polymethylmethacrylate were dispersed in the polymer via a solvent casting method. The volume fraction of the spheres was varied from 5% to 30%, thus allowing to explore both dilute and concentrated regimes. Electron scanning microscopy demonstrated homogeneous dispersion of the spheres in the matrix. We measured the rheological properties of the suspensions both in linear and nonlinear regimes with both dynamic and transient tests. The experimental results demonstrate the reinforcement effect of the particles. Both viscous and elastic moduli increase as the concentration of the particles is increased. The results show good agreement with available theories, simulations, and previous experimental data. In particular, the second order parameter of the quadratic equation that describes the dependence of the shear viscosity of the suspension upon the volume fraction of particles is in agreement with the predicted value found by Batchelor [G. K. Batchelor and J. T. Green, “The hydrodynamic interaction of two small freely-moving spheres in a linear flow field,” J. Fluid Mech. 56, 375–400 (1972); G. K. Batchelor and J. T. Green, “The determination of the bulk stress in a suspension of spherical particles to order c2,” J. Fluid Mech. 56, 401–427 (1972); and G. K. Batchelor, “The effect of Brownian motion on the bulk stress in a suspension of spherical particles,” J. Fluid Mech. 83, 97–117 (1977)]. We probe experimentally that the linear rheological behavior of suspensions of particles in viscoelastic fluids is the same as for Newtonian fluids.

Special Issue on Nanofluids and Their Applications

Nanofluids can be considered as engineered colloidal suspensions of nanometer-sized particles in a base fluid of water, ethylene glycol, or oil [...]

Experimental investigation of a novel type of two-phase closed thermosyphon filled with functionalized carbon nanotubes/water nanofluids for electronic cooling application

Two-phase closed thermosyphon as a gravity-assisted heat pipe is an efficient heat transfer device in which heat transmits by evaporation and condensation of a working fluid. Nanofluids are suspensions of nano-sized solid particles in a base fluid which can be used as heat transfer media in the thermosyphon. In the present study, thermal performance of functionalized multi-walled carbon nanotubes/water nanofluids was investigated in a novel type of thermosyphon which was made of an evaporator with square frustum shape, and a condenser composed of two connected tubes. To prepare nanofluids, multi-walled carbon nanotubes were first functionalized using two oxidant agents (potassium persulfate and sodium persulfate) to improve the cooling performance of nanofluids. The prepared nanofluids were characterized by Fourier transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, zeta potential, and thermal conductivity analyzer. The results of characterization showed that the nanofluid with sodium functional group had higher stability as well as higher thermal conductivity. Thermal efficiency and thermal resistance were calculated to evaluate the thermal performance of thermosyphon. Using nanofluid with sodium functional group in the thermosyphon showed better performance in terms of higher thermal efficiency and lower thermal resistance. Experimental results also showed that the thermosyphon could perform at higher input powers (up to 90 W) using the nanofluid compared to water (up to 70 W). Furthermore, the results of the temperature distribution of thermosyphon during the test confirmed that two connected tubes in the condenser section could provide pathways for both condensate liquid and vapor. In other words, this behavior indicated that this type of thermosyphon can be considered between a tubular thermosyphon and a loop thermosyphon.

Three-Dimensional Boundary layer Flow and Heat Transfer of a Fluid Particle Suspension over a Stretching Sheet Embedded in a Porous Medium

Abstract This article presents the effect of nonlinear thermal radiation on three dimensional flow and heat transfer of fluid particle suspension over a stretching sheet. The combined effects of non-uniform source/sink and convective boundary condition are taken into consideration. The governing partial differential equations are transformed into ordinary differential equations using similarity variables, which are then solved numerically by using Runge Kutta Fehlberg-45 method with shooting technique. The influence of various parameters on velocity and temperature profiles are illustrated graphically, and discussed in detail. The results indicate that the fluid phase velocity is greater than that of the particle phase for various existing parameters.

Dynamic clustering and re-dispersion in concentrated colloid-active gel composites.

We study the dynamics of quasi-two-dimensional concentrated suspensions of colloidal particles in active gels by computer simulations. Remarkably, we find that activity induces a dynamic clustering of colloids even in the absence of any preferential anchoring of the active nematic director at the particle surface. When such an anchoring is present, active stresses instead compete with elastic forces and re-disperse the aggregates observed in passive colloid-liquid crystal composites. Our quasi-two-dimensional "inverse" dispersions of passive particles in active fluids (as opposed to the more common "direct" suspensions of active particles in passive fluids) provide a promising route towards the self-assembly of new soft materials.

Concurrent Development of Thermal Energy with Magnetic Field on a Particle-Fluid Suspension Through a Porous Conduit

The impact of heat transfer on the magnetohydrodynamic peristaltically induced motion in a channel through porous medium has been investigated. The continuity, momentum, and energy equations have been utilized to represent the flow in a closed form. These non-linear governing equations are solved analytically by employing the perturbation method. The obtained expressions for streamlines, temperature, and heat transfer coefficient are presented through graphs for two dimensions with a small wave number. The variations of physical variables with the pertinent parameters have been presented and discussed. It has been found that the inclusion of fluid suspension brought about a decrease in the temperature distribution. The effect of magnetic field on the temperature of fluid has also been seen to depend upon the position and time.

Exploring the Use of Alumina Nanofluid as Emergency Coolant for Nuclear Fuel Bundle

Abstract Nanofluids are suspensions of nanosized particles in any base fluid that show significant enhancement of their heat transfer properties at modest nanoparticle concentrations. Due to enhanced thermal properties at low nanoparticle concentration, it is a potential candidate for utilization in nuclear heat transfer applications. In the last decade, there have been few studies which indicate possible advantages of using nanofluids as a coolant in nuclear reactors during normal as well as accidental conditions. In continuation with these studies, the utilization of nanofluids as a viable candidate for emergency core cooling in nuclear reactors is explored in this paper by carrying out experiments in a scaled facility. The experiments carried out mainly focus on quenching behavior of a simulated nuclear fuel rod bundle by using 1% Alumina nanofluid as a coolant in emergency core cooling system (ECCS). In addition, its performance is compared with water. In the experiments, nuclear decay heat (from 1.5% to 2.6% reactor full power) is simulated through electrical heating. The present experiments show that, from heat transfer point of view, alumina nanofluids have a definite advantage over water as coolant for ECCS. Additionally, to assess the suitability of using nanofluids in reactors, their stability was investigated in radiation field. Our tests showed good stability even after very high dose of radiation, indicating the feasibility of their possible use in nuclear reactor heat transfer systems.

Pair-particle trajectories in a shear flow of a Bingham fluid

We study numerically the pair trajectories of rigid circular particles in a two dimensional inertialess simple shear flow of a (Binghamian) yield stress fluid. We use a Lagrange multiplier based fictitious domain method, following Glowinski et al. [26, 28, 29], for solving the problem. Contacts between the particles at a finite interparticle distance interpreted as a roughness are taken into account with the da Cunha and Hinch [12] model. Another model, introduced by Glowinski et al. [27], is shown to provide similar results in the limit of infinite contact stiffness. Due to the nonlinear behavior of the suspending fluid, it is found that the trajectories of the particles depend on the shear rate, the relevant dimensionless parameter being here the Bingham number, which compares plastic forces to viscous forces. In absence of interparticle contacts, fore-aft symmetry is observed in all cases; however, the particles are found to come closer to each other as the Bingham number is increased: the plastic behavior of the suspending fluid decreases the range of hydrodynamic interactions. As contacts are introduced, fore-aft asymmetry is observed. Plastic effects are found to enhance surface roughness effects: contacts between particles occur for smaller surface roughness at large Bn. Moreover, the magnitude of the asymmetry is increased as the Bingham number is increased. These observations may explain why the microstructure of suspensions of particles in a yield stress fluid is shear-rate-dependent [45] leading to a complex nonlinear macroscopic behavior.

MHD Flow of Dusty Fluid Past a Stretching Sheet with Slip Effect Using Carreau Model

This examination manages the impact of magnetic field on the flow and heat transport of an incompressible Carreau liquid over an extending sheet with particle fluid suspension. The significant conditions are first improved under regular boundary layer suppositions, and afterward changed into conventional differential conditions by reasonable transformations. The changed conventional nonlinear differential conditions which are explained numerically by Matlab bvp4c package. The impacts of specific parameters on the dimensionless velocity and temperature are exhibited in graphical structures.

Unsteady Peristaltic Transport of a Particle-Fluid Suspension: Application to Oesophageal Swallowing

Abstract This model characterises the flow behaviour of suspended particles when swallowing through oesophagus. Transport of particle-fluid mixture induced by dilating peristaltic waves on a circular cylindrical tube was considered for investigation. Unsteady closed-form solutions for pressure gradient, velocity and stream function are obtained by applying regular perturbation technique up to the first order of wavenumber (the ratio of the tube radius to the wavelength). It is observed that the axial velocity of the fluid is greater than that of the solid particles almost everywhere. However, at the wall the axial velocity of the fluid is zero due to the no-slip condition imposed on it; but the suspended particulate material has non-zero positive axial velocity. Thus, the axial velocity of the suspended particles near the tube wall is more than that of the fluid velocity. It is further observed that the axial velocity is negative in the regions close to maximum occlusions giving way to instantaneous backward flow. It is also inferred that the maximum axial velocity of the particle-fluid suspension with non-zero wavenumber is more than that of the particle-free fluid with zero wavenumber. We examined the effect of volume fraction of suspended particulate matter on pressure gradient and velocity. An increase in the volume fraction diminished the pumping performance and also the axial and radial velocities. The results are also compared with those which were obtained for zero wavenumber. The outcome of the investigation endorses the doctors’ advice to patients suffering from achalasia, oesophageal stricture and oesophageal tumors to take liquid or food items with lesser solid contents. Streamline patterns are changed by increasing the flow rate while trapping occurs at high flow rates.

Numerical solutions for unsteady boundary layer flow of a dusty fluid past a permeable stretching/shrinking surface with particulate viscous effect

PurposeThis present aims to present the numerical study of the unsteady stretching/shrinking flow of a fluid-particle suspension in the presence of the constant suction and dust particle slip on the surface.Design/methodology/approachThe governing partial differential equations for the two phases flows of the fluid and the dust particles are reduced to the pertinent ordinary differential equations using a similarity transformation. The numerical results are obtained using the bvp4c function in the Matlab software.FindingsThe results revealed that in the decelerating shrinking flow, the wall skin friction is higher in the dusty fluid when compared to the clean fluid. In addition, the effect of the fluid-particle interaction parameter to the fluid-phase can be seen more clearly in the shrinking flow. Other non-dimensional physical parameters such as the unsteadiness parameter, the mass suction parameter, the viscosity ratio parameter, the particle slip parameter and the particle loading parameter are also considered and presented in figures. Further, the second solution is discovered in this problem and the solution expanded with higher unsteadiness and suction values. Hence, the stability analysis is performed, and it is confirmed that the second solution is unstable.Practical implicationsIn practice, the flow conditions are commonly varying with time; thus, the study of the unsteady flow is very crucial and useful. The problem of unsteady flow of a dusty fluid has a wide range of possible applications such as in the centrifugal separation of particles, sedimentation and underground disposable of radioactive waste materials.Originality/valueEven though the problem of dusty fluid has been broadly investigated, limited discoveries can be found over an unsteady shrinking flow. Indeed, this paper managed to obtain the second (dual) solutions, and stability analysis is performed. Furthermore, the authors also considered the artificial particle-phase viscosity, which is an important term to study the particle-particle and particle-wall interactions. With the addition of this term, the effects of the particle slip and suction parameters can be investigated. Very few studies in the dusty fluid embedded this parameter in their problems.