**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**35

# Search results for: Non-Newtonian

##### 35 Magnetohydrodynamic Maxwell Nanofluids Flow over a Stretching Surface through a Porous Medium: Effects of Non-Linear Thermal Radiation, Convective Boundary Conditions and Heat Generation/Absorption

**Authors:**
Sameh E. Ahmed,
Ramadan A. Mohamed,
Abd Elraheem M. Aly,
Mahmoud S. Soliman

**Abstract:**

In this paper, an enhancement of the heat transfer using non-Newtonian nanofluids by magnetohydrodynamic (MHD) mixed convection along stretching sheets embedded in an isotropic porous medium is investigated. Case of the Maxwell nanofluids is studied using the two phase mathematical model of nanofluids and the Darcy model is applied for the porous medium. Important effects are taken into account, namely, non-linear thermal radiation, convective boundary conditions, electromagnetic force and presence of the heat source/sink. Suitable similarity transformations are used to convert the governing equations to a system of ordinary differential equations then it is solved numerically using a fourth order Runge-Kutta method with shooting technique. The main results of the study revealed that the velocity profiles are decreasing functions of the Darcy number, the Deborah number and the magnetic field parameter. Also, the increase in the non-linear radiation parameters causes an enhancement in the local Nusselt number.

**Keywords:**
MHD,
nanofluids,
stretching surface,
non-linear thermal radiation,
convective condition.

##### 34 Oscillatory Electroosmotic Flow of Power-Law Fluids in a Microchannel

**Authors:**
Rubén Bãnos,
José Arcos,
Oscar Bautista,
Federico Méndez

**Abstract:**

**Keywords:**
Oscillatory electroosmotic flow,
Non-Newtonian
fluids,
power-law model,
low zeta potentials.

##### 33 Effect of Non-Newtonian Behavior of Oil Phase on Oil-Water Stratified Flow in a Horizontal Channel

**Authors:**
Satish Kumar Dewangan,
Santosh Kumar Senapati

**Abstract:**

The present work focuses on the investigation of the effect of non-Newtonian behavior on the oil-water stratified flow in a horizontal channel using ANSYS Fluent. Coupled level set and volume of fluid (CLSVOF) has been used to capture the evolving interface assuming unsteady, coaxial flow with constant fluid properties. The diametric variation of oil volume fraction, mixture velocity, total pressure and pressure gradient has been studied. Non-Newtonian behavior of oil has been represented by the power law model in order to investigate the effect of flow behavior index. Stratified flow pattern tends to assume dispersed flow pattern with the change in the behavior of oil to non-Newtonian. The pressure gradient is found to be very much sensitive to the flow behavior index. The findings could be useful in designing the transportation pipe line in petroleum industries.

**Keywords:**
Oil-water stratified flow,
horizontal channel,
CLSVOF,
non–Newtonian behavior.

##### 32 Computational Fluid Dynamics Simulation and Comparison of Flow through Mechanical Heart Valve Using Newtonian and Non-Newtonian Fluid

**Authors:**
D. Šedivý,
S. Fialová

**Abstract:**

**Keywords:**
Computational modeling,
dynamic mesh,
mechanical heart valve,
non-Newtonian fluid,
SDOF.

##### 31 Heat Transfer Dependent Vortex Shedding of Thermo-Viscous Shear-Thinning Fluids

**Authors:**
Markus Rütten,
Olaf Wünsch

**Abstract:**

**Keywords:**
Heat transfer,
thermo-viscous fluids,
shear thinning,
vortex shedding.

##### 30 Unsteady Natural Convection Heat and Mass Transfer of Non-Newtonian Casson Fluid along a Vertical Wavy Surface

**Authors:**
A. Mahdy,
Sameh E. Ahmed

**Abstract:**

**Keywords:**
Casson fluid,
wavy surface,
mass transfer,
transient analysis.

##### 29 Transport of Analytes under Mixed Electroosmotic and Pressure Driven Flow of Power Law Fluid

**Authors:**
Naren Bag,
S. Bhattacharyya,
Partha P. Gopmandal

**Abstract:**

**Keywords:**
Electric double layer,
finite volume method,
flow behavior index,
mixed electroosmotic/pressure driven flow,
Non-Newtonian power-law fluids,
numerical simulation.

##### 28 Rheological Characteristics of Ice Slurries Based on Propylene- and Ethylene-Glycol at High Ice Fractions

**Authors:**
Senda Trabelsi,
Sébastien Poncet,
Michel Poirier

**Abstract:**

Ice slurries are considered as a promising phase-changing secondary fluids for air-conditioning, packaging or cooling industrial processes. An experimental study has been here carried out to measure the rheological characteristics of ice slurries. Ice slurries consist in a solid phase (flake ice crystals) and a liquid phase. The later is composed of a mixture of liquid water and an additive being here either (1) Propylene-Glycol (PG) or (2) Ethylene-Glycol (EG) used to lower the freezing point of water. Concentrations of 5%, 14% and 24% of both additives are investigated with ice mass fractions ranging from 5% to 85%. The rheological measurements are carried out using a Discovery HR-2 vane-concentric cylinder with four full-length blades. The experimental results show that the behavior of ice slurries is generally non-Newtonian with shear-thinning or shear-thickening behaviors depending on the experimental conditions. In order to determine the consistency and the flow index, the Herschel-Bulkley model is used to describe the behavior of ice slurries. The present results are finally validated against an experimental database found in the literature and the predictions of an Artificial Neural Network model.

**Keywords:**
Ice slurry,
propylene-glycol,
ethylene-glycol,
rheology,
artificial neural network.

##### 27 Experimental Investigation to Find Transition Temperature of VG-30 Binder

**Authors:**
D. Latha,
V. Sunitha,
Samson Mathew

**Abstract:**

**Keywords:**
Unmodified and modified binders,
Brookfield
Viscometer,
transition temperature,
steady shear,
shear rate protocol.

##### 26 Flow of a Second Order Fluid through Constricted Tube with Slip Velocity at Wall Using Integral Method

**Authors:**
Nosheen Zareen Khan,
Abdul Majeed Siddiqui,
Muhammad Afzal Rana

**Abstract:**

**Keywords:**
Approximate solution,
constricted tube,
non-Newtonian fluids,
Reynolds number.

##### 25 Numerical Investigation of Unsteady MHD Flow of Second Order Fluid in a Tube of Elliptical Cross-Section on the Porous Boundary

**Authors:**
S. B. Kulkarni,
Hasim A. Chikte,
V. Murali Mohan

**Abstract:**

**Keywords:**
Elastico-viscous fluid,
Porous media,
Elliptic cross-section,
Magnetic parameter,
Numerical Simulation.

##### 24 Mixing Behaviors of Shear-Thinning Fluids in Serpentine-Channel Micromixers

**Authors:**
Rei-Tang Tsai,
Chih-Yang Wu,
Chia-Yuan Chang,
Ming-Ying Kuo

**Abstract:**

**Keywords:**
Microfluidics,
mixing,
non-Newtonian fluids,
curved
channel,
vortex.

##### 23 Unsteady MHD Flow of an Incompressible Elastico-Viscous Fluid in a Tube of Spherical Cross Section on a Porous Boundary

**Authors:**
Sanjay Baburao Kulkarni

**Abstract:**

Exact solution of an unsteady MHD flow of elasticoviscous fluid through a porous media in a tube of spherical cross section under the influence of magnetic field and constant pressure gradient has been obtained in this paper. Initially, the flow is generated by a constant pressure gradient. After attaining the steady state, the pressure gradient is suddenly withdrawn and the resulting fluid motion in a tube of spherical cross section by taking into account of the porosity factor and magnetic parameter of the bounding surface is investigated. The problem is solved in two-stages the first stage is a steady motion in tube under the influence of a constant pressure gradient, the second stage concern with an unsteady motion. The problem is solved employing separation of variables technique. The results are expressed in terms of a non-dimensional porosity parameter (K), magnetic parameter (m) and elasticoviscosity parameter (β), which depends on the Non-Newtonian coefficient. The flow parameters are found to be identical with that of Newtonian case as elastic-viscosity parameter and magnetic parameter tends to zero and porosity tends to infinity. It is seen that the effect of elastico-viscosity parameter, porosity parameter and magnetic parameter of the bounding surface has significant effect on the velocity parameter.

**Keywords:**
Elastico-viscous fluid,
Porous media,
Second order
fluids,
Spherical cross-section,
Magnetic parameter.

##### 22 Unsteady Poiseuille Flow of an Incompressible Elastico-Viscous Fluid in a Tube of Spherical Cross Section on a Porous Boundary

**Authors:**
Sanjay Baburao Kulkarni

**Abstract:**

Exact solution of an unsteady flow of elastico-viscous fluid through a porous media in a tube of spherical cross section under the influence of constant pressure gradient has been obtained in this paper. Initially, the flow is generated by a constant pressure gradient. After attaining the steady state, the pressure gradient is suddenly withdrawn and the resulting fluid motion in a tube of spherical cross section by taking into account of the porosity factor of the bounding surface is investigated. The problem is solved in twostages the first stage is a steady motion in tube under the influence of a constant pressure gradient, the second stage concern with an unsteady motion. The problem is solved employing separation of variables technique. The results are expressed in terms of a nondimensional porosity parameter (K) and elastico-viscosity parameter (β), which depends on the Non-Newtonian coefficient. The flow parameters are found to be identical with that of Newtonian case as elastic-viscosity parameter tends to zero and porosity tends to infinity. It is seen that the effect of elastico-viscosity parameter, porosity parameter of the bounding surface has significant effect on the velocity parameter.

**Keywords:**
Elastico-viscous fluid,
Porous media,
Second order
fluids,
Spherical cross-section.

##### 21 Unsteady Flow of an Incompressible Elastico-Viscous Fluid of Second order Type in Tube of Ellipsoidal Cross Section on a Porous Boundary

**Authors:**
Sanjay Baburao Kulkarni

**Abstract:**

Exact solution of an unsteady flow of elastico-viscous fluid through a porous media in a tube of ellipsoidal cross section under the influence of constant pressure gradient has been obtained in this paper. Initially, the flow is generated by a constant pressure gradient. After attaining the steady state, the pressure gradient is suddenly withdrawn and the resulting fluid motion in a tube of ellipsoidal cross section by taking into account of the porosity factor of the bounding surface is investigated. The problem is solved in twostages the first stage is a steady motion in tube under the influence of a constant pressure gradient, the second stage concern with an unsteady motion. The problem is solved employing separation of variables technique. The results are expressed in terms of a nondimensional porosity parameter (K) and elastico-viscosity parameter (β), which depends on the Non-Newtonian coefficient. The flow parameters are found to be identical with that of Newtonian case as elastic-viscosity parameter tends to zero and porosity tends to infinity. It is seen that the effect of elastico-viscosity parameter and the porosity parameter of the bounding surface has significant effect on the velocity parameter.

**Keywords:**
Elastico-viscous fluid,
Ellipsoidal cross-section,
Porous media,
Second order fluids.

##### 20 Effect of Bentonite on the Rheological Behavior of Cement Grout in Presence of Superplasticizer

**Authors:**
K. Benyounes,
A. Benmounah

**Abstract:**

Cement-based grouts has been used successfully to repair cracks in many concrete structures such as bridges, tunnels, buildings and to consolidate soils or rock foundations. In the present study the rheological characterization of cement grout with water/binder ratio (W/B) is fixed at 0.5. The effect of the replacement of cement by bentonite (2 to 10% wt) in presence of superplasticizer (0.5% wt) was investigated. Several rheological tests were carried out by using controlled-stress rheometer equipped with vane geometry in temperature of 20°C. To highlight the influence of bentonite and superplasticizer on the rheological behavior of grout cement, various flow tests in a range of shear rate from 0 to 200 s-1 were observed. Cement grout showed a non-Newtonian viscosity behavior at all concentrations of bentonite. Three parameter model Herschel- Bulkley was chosen for fitting of experimental data. Based on the values of correlation coefficients of the estimated parameters, The Herschel-Bulkley law model well described the rheological behavior of the grouts. Test results showed that the dosage of bentonite increases the viscosity and yield stress of the system and introduces more thixotropy. While the addition of both bentonite and superplasticizer with cement grout improve significantly the fluidity and reduced the yield stress due to the action of dispersion of SP.

**Keywords:**
Cement grout,
bentonite,
superplasticizer,
viscosity,
yield stress.

##### 19 Numerical Comparison of Rushton Turbine and CD-6 Impeller in Non-Newtonian Fluid Stirred Tank

**Authors:**
Akhilesh Khapre,
Basudeb Munshi

**Abstract:**

A computational fluid dynamics simulation is done for non-Newtonian fluid in a baffled stirred tank. The CMC solution is taken as non-Newtonian shear thinning fluid for simulation. The Reynolds Average Navier Stocks equation with steady state multi reference frame approach is used to simulate flow in the stirred tank. The turbulent flow field is modelled using realizable k-ε turbulence model. The simulated velocity profiles of Rushton turbine is validated with literature data. Then, the simulated flow field of CD-6 impeller is compared with the Rushton turbine. The flow field generated by CD-6 impeller is less in magnitude than the Rushton turbine. The impeller global parameter, power number and flow number, and entropy generation due to viscous dissipation rate is also reported.

**Keywords:**
Computational fluid dynamics,
non-Newtonian,
Rushton turbine,
CD-6 impeller,
power number,
flow number,
viscous dissipation rate.

##### 18 CFD Simulation of Surge Wave Generated by Flow-Like Landslides

**Authors:**
Liu-Chao Qiu

**Abstract:**

**Keywords:**
Flow-like landslide,
surge wave,
VOF,
non-Newtonian fluids,
multi-phase flows,
free surface flow.

##### 17 Natural Convection in Wavy-Wall Cavities Filled with Power-Law Fluid

**Authors:**
Cha’o-Kuang Chen,
Ching-Chang Cho

**Abstract:**

This paper investigates the natural convection heat transfer performance in a complex-wavy-wall cavity filled with power-law fluid. In performing the simulations, the continuity, Cauchy momentum and energy equations are solved subject to the Boussinesq approximation using a finite volume method. The simulations focus specifically on the effects of the flow behavior index in the power-law model and the Rayleigh number on the flow streamlines, isothermal contours and mean Nusselt number within the cavity. The results show that pseudoplastic fluids have a better heat transfer performance than Newtonian or dilatant fluids. Moreover, it is shown that for Rayleigh numbers greater than *Ra*=10^{3}, the mean Nusselt number has a significantly increase as the flow behavior index is decreased.

**Keywords:**
Non-Newtonian fluid,
Power-law fluid,
Natural convection,
Heat transfer enhancement,
Cavity,
Wavy wall.

##### 16 MHD Non-Newtonian Nanofluid Flow over a Permeable Stretching Sheet with Heat Generation and Velocity Slip

**Authors:**
Rama Bhargava,
Mania Goyal

**Abstract:**

The problem of magnetohydrodynamics boundary layer flow and heat transfer on a permeable stretching surface in a second grade nanofluid under the effect of heat generation and partial slip is studied theoretically. The Brownian motion and thermophoresis effects are also considered. The boundary layer equations governed by the PDE’s are transformed into a set of ODE’s with the help of local similarity transformations. The differential equations are solved by variational finite element method. The effects of different controlling parameters on the flow field and heat transfer characteristics are examined. The numerical results for the dimensionless velocity, temperature and nanoparticle volume fraction as well as the reduced Nusselt and Sherwood number have been presented graphically. The comparison confirmed excellent agreement. The present study is of great interest in coating and suspensions, cooling of metallic plate, oils and grease, paper production, coal water or coal-oil slurries, heat exchangers technology, materials processing exploiting.

**Keywords:**
Viscoelastic nanofluid,
partial slip,
stretching sheet,
heat generation/absorption,
MHD flow,
FEM.

##### 15 Numerical Investigation of Non-Newtonians Fluids Flows between Two Rotating Cylinders Using Lattice Boltzmann Method

**Authors:**
S. Khali,
R. Nebbali,
K. Bouhadef

**Abstract:**

A numerical investigation is performed for non Newtonian fluids flow between two concentric cylinders. The D2Q9 lattice Boltzmann model developed from the Bhatangar-Gross-Krook (LBGK) approximation is used to obtain the flow field for fluids obeying to the power-law model. The inner and outer cylinders rotate in the same and the opposite direction while the end walls are maintained at rest. The combined effects of the Reynolds number (Re) of the inner and outer cylinders, the radius ratio (η) as well as the power-law index (n) on the flow characteristics are analyzed for an annular space of a finite aspect ratio (Γ). Two flow modes are obtained: a primary mode (laminar stable regime) and a secondary mode (laminar unstable regime). The so obtained flow structures are different from one mode to another. The transition critical Reynolds number Re_{c} from the primary to the secondary mode is analyzed for the co-courant and counter-courant flows. This critical value increases as n increases. The prediction of the swirling flow of non Newtonians fluids in axisymmetric geometries is shown in the present work.

**Keywords:**
Taylor-Couette flows,
non Newtonian fluid,
Lattice Boltzmann method.

##### 14 Numerical Investigation into Mixing Performance of Electrokinetically-Driven Power-Law Fluids in Microchannel with Patterned Trapezoid Blocks

**Authors:**
Cha’o-Kuang Chen,
Ching-Chang Cho

**Abstract:**

The study investigates the mixing performance of electrokinetically-driven power-law fluids in a microchannel containing patterned trapezoid blocks. The effects of the geometry parameters of the patterned trapezoid blocks and the flow behavior index in the power-law model on the mixing efficiency within the microchannel are explored. The results show that the mixing efficiency can be improved by increasing the width of the blocks and extending the length of upper surface of the blocks. In addition, the results show that the mixing efficiency increases with an increasing flow behavior index. Furthermore, it is shown that a heterogeneous patterning of the zeta potential on the upper surfaces of the trapezoid blocks prompts the formation of local flow recirculations, and therefore improves the mixing efficiency. Consequently, it is shown that the mixing performance improves with an increasing magnitude of the heterogeneous surface zeta potential.

**Keywords:**
Non-Newtonian fluid,
Power-law fluid,
Electroosmotic flow,
Passive mixer,
Mixing,
Micromixer.

##### 13 The Influence of Gravity on The Temporal Instability of Viscoelastic Liquid Curved Jets

**Authors:**
Abdullah Madhi Alsharif,
Jamal Uddin

**Abstract:**

A liquid curved jet has many applications in different industrial and engineering processes, such as the prilling process for generating small spherical pellets (fertilizer or magnesium). The liquids used are usually molten and contain small quantities of polymers and therefore can be modelled as non-Newtonian liquids. In this paper, we model the viscoelastic liquid jet by using the Oldroyd- B model. An asymptotic analysis has been used to simplify the governing equations. Furthermore, the trajectory and a linear temporal stability in the presence of gravity and rotation have been determined.

**Keywords:**
gravity,
prilling,
rotation,
viscoelastic jets.

##### 12 Influence of Heat Transfer on Stability of Newtonian and Non-Newtonian Extending Films

**Authors:**
Olus N. Boratav,
Zheming Zheng,
Chunfeng Zhou

**Abstract:**

The stability of Newtonian and Non-Newtonian extending films under local or global heating or cooling conditions are considered. The thickness-averaged mass, momentum and energy equations with convective and radiative heat transfer are derived, both for Newtonian and non-Newtonian fluids (Maxwell, PTT and Giesekus models considered). The stability of the system is explored using either eigenvalue analysis or transient simulations. The results showed that the influence of heating and cooling on stability strongly depends on the magnitude of the Peclet number. Examples of stabilization or destabilization of heating or cooling are shown for Pe<< 1, and Pe = O(1) cases, for Newtonian and non-Newtonian flows.

**Keywords:**
Extended films,
stability,
eigen-analysis for stability,
transient response,
polymer instability,
Non-Newtonian fluids.

##### 11 Rheological Behaviors of Crude Oil in the Presence of Water

**Authors:**
Madjid Meriem-Benziane,
Hamou Zahloul

**Abstract:**

The rheological properties of light crude oil and its mixture with water were investigated experimentally. These rheological properties include steady flow behavior, yield stress, transient flow behavior, and viscoelastic behavior. A RheoStress RS600 rheometer was employed in all of the rheological examination tests. The light crude oil exhibits a Newtonian and for emulsion exhibits a non-Newtonian shear thinning behavior over the examined shear rate range of 0.1–120 s-1. In first time, a series of samples of crude oil from the Algerian Sahara has been tested and the results expressed in terms of τ=f(γ) have demonstrated their Newtonian character for the temperature included in [20°C, 70°C]. In second time and at T=20°C, the oil-water emulsions (30%, 50% and 70%) by volume of water), thermodynamically stable, have demonstrated a non-Newtonian rheological behavior that is to say, Herschel-Bulkley and Bingham types. For each type of crude oil-water emulsion, the rheological parameters are calculated by numerical treatment of results.

**Keywords:**
Crude oil Algerian,
Emulsion,
Newtonian,
Non- Newtonian,
viscosity.

##### 10 Experimental Study of Light Crude Oil-Water Emulsions

**Authors:**
M. Meriem-Benziane,
Sabah A. Abdul-Wahab,
H. Zahloul,
M. Belhadri

**Abstract:**

This paper made an attempt to investigate the problem associated with enhancement of emulsions of light crude oil-water recovery in an oil field of Algerian Sahara. Measurements were taken through experiments using RheoStress (RS600). Factors such as shear rate, temperature and light oil concentration on the viscosity behavior were considered. Experimental measurements were performed in terms of shear stress–shear rate, yield stress and flow index on mixture of light crude oil–water. The rheological behavior of emulsion showed Non-Newtonian shear thinning behavior (Herschel-Bulkley). The experiments done in the laboratory showed the stability of some water in light crude oil emulsions form during consolidate oil recovery process. To break the emulsion using additives may involve higher cost and could be very expensive. Therefore, further research should be directed to find solution of these problems that have been encountered.

**Keywords:**
Emulsion,
Flow index,
Herschel-Bulkley model,
Newton model,
Oil field,
Rheology,
Yield stress

##### 9 Numerical Simulation of unsteady MHD Flow and Heat Transfer of a Second Grade Fluid with Viscous Dissipation and Joule Heating using Meshfree Approach

**Authors:**
R. Bhargava,
Sonam Singh

**Abstract:**

**Keywords:**
EFGM,
MHD,
Oscillatory stretching sheet,
Unsteady,
Viscoelastic

##### 8 Analysis of Foaming Flow Instabilities for Dynamic Liquid Saturation in Trickle Bed Reactor

**Authors:**
Vijay Sodhi,
Ajay Bansal

**Abstract:**

**Keywords:**
Trickle Bed Reactor,
Dynamic Liquid Saturation,
Foaming,
Flow Regime Transition

##### 7 CFD Simulation of Non-Newtonian Fluid Flow in Arterial Stenoses with Surface Irregularities

**Authors:**
R. Manimaran

**Abstract:**

**Keywords:**
Blood flow,
Roughness,
Computational fluid
dynamics,
Bio fluid mechanics.

##### 6 Time Independent Behavior of Tomato Paste

**Authors:**
A. Heidarinasab,
V. Moghaddam Nansa

**Abstract:**

**Keywords:**
Breaking temperature,
Concentration,
Power law,
Rheology,
Time independent.