scholarly journals Experimental studies on the viscosity of Fe nanoparticles dispersed in ethylene glycol and water mixture

2016 ◽  
Vol 20 (5) ◽  
pp. 1661-1670 ◽  
Author(s):  
Amir Karimi ◽  
Sadatlu Abdolahi ◽  
Mehdi Ashjaee
Keyword(s):  
Ethylene Glycol ◽  
Base Fluid ◽  
Volume Concentration ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Experimental Results ◽  
Water Mixture ◽  
Fe Nanoparticles

In this paper, experimental studies are conducted in order to measure the viscosity of Fe nanoparticles dispersed in various weight concentration (25/75%, 45/55% and 55/45%) of ethylene glycol and water (EG-water) mixture. The experimental measurements are performed at various volume concentrations up to 2% and temperature ranging from 10?C to 60?C. The experimental results disclose that the viscosity of nanofluids increases with increase in Fe particle volume fraction, and decreases with increase in temperature. Maximum enhancement in viscosity of nanofluids is 2.14 times for 55/45% EG-water based nanofluid at 2% volume concentration compared to the base fluid. Moreover, some comparisons between experimental results and theoretical models are drawn. It is also observed that the prior theoretical models do not estimate the viscosity of nanofluid accurately. Finally, a new empirical correlation is proposed to predict the viscosity of nanofluids as a function of volume concentration, temperature, and the viscosity of base fluid.

scholarly journals Electrical Conductivity of New Nanoparticle Enhanced Fluids: An Experimental Study

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1228 ◽  
Author(s):  
Chereches ◽  
Minea
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Base Fluid ◽  
Volume Concentration ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Sio2 Nanoparticles ◽  
Theoretical Models ◽  
Conductivity Ratio ◽  
Hybrid Nanofluids

In this research, the electrical conductivity of simple and hybrid nanofluids containing Al2O3, TiO2 and SiO2 nanoparticles and water as the base fluid was experimentally studied at ambient temperature and with temperature variation in the range of 20–60 °C. A comparison of the experimental data with existing theoretical models demonstrated that the theoretical models under-predict the experimental data. Consequently, several correlations were developed for nanofluid electrical conductivity estimation in relation to temperature and volume concentration. The electrical conductivity of both simple and hybrid nanofluids increased linearly with both volume concentration and temperature upsurge. More precisely, by adding nanoparticles to water, the electrical conductivity increased from 11 times up to 58 times for both simple and hybrid nanofluids, with the maximum values being attained for the 3% volume concentration. Plus, a three-dimensional regression analysis was performed to correlate the electrical conductivity with temperature and volume fraction of the titania and silica nanofluids. The thermo-electrical conductivity ratio has been calculated based on electrical conductivity experimental results and previously determined thermal conductivity. Very low figures were noticed. Concluding, one may affirm that further experimental work is needed to completely elucidate the behavior of nanofluids in terms of electrical conductivity.

scholarly journals The Investigation of Effects of Temperature and Nanoparticles Volume Fraction on the Viscosity of Copper Oxide-ethylene Glycol Nanofluids

2017 ◽  
Author(s):  
Mohammad Hemmat Esfe
Keyword(s):  
Ethylene Glycol ◽  
Copper Oxide ◽  
Volume Fraction ◽  
Relative Viscosity ◽  
Experimental Results ◽  
Different Temperatures ◽  
Nanoparticles Volume Fraction ◽  
Effects Of Temperature ◽  
Nanofluid Viscosity ◽  
Experimental Values

In the present article, the effects of temperature and nanoparticles volume fraction on the viscosity of copper oxide-ethylene glycol nanofluid have been investigated experimentally. The experiments have been conducted in volume fractions of 0 to 1.5 % and temperatures from 27.5 to 50 °C. The shear stress computed by experimental values of viscosity and shear rate for volume fraction of 1% and in different temperatures show that this nanofluid has Newtonian behaviour. The experimental results reveal that in a given volume fraction when temperature increases, viscosity decreases, but relative viscosity varies. Also, in a specific temperature, nanofluid viscosity and relative viscosity increase when volume fraction increases. The maximum amount of increase in relative viscosity is 82.46% that occurs in volume fraction of 1.5% and temperature of 50 °C. Some models of computing nanofluid viscosity have been suggested. The greatest difference between the results obtained from these models and experimental results was down of 4 percent that shows that there is a very good agreement between experimental results and the results obtained from these models.

scholarly journals Numerical analysis of heat transfer enhancement with the use of γ-Al2O3/water nanofluid and longitudinal ribs in a curved duct

2012 ◽  
Vol 16 (2) ◽  
pp. 469-480 ◽  
Author(s):  
Hosseinali Soltanipour ◽  
Parisa Choupani ◽  
Iraj Mirzaee
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Base Fluid ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Transfer Enhancement ◽  
Dean Number ◽  
Particle Volume ◽  
The Heat Transfer Coefficient

This paper presents a numerical investigation of heat transfer augmentation using internal longitudinal ribs and ?-Al2O3/ water nanofluid in a stationary curved square duct. The flow is assumed 3D, steady, laminar, and incompressible with constant properties. Computations have been done by solving Navier-Stokes and energy equations utilizing finite volume method. Water has been selected as the base fluid and thermo- physical properties of ?- Al2o3/ water nanofluid have been calculated using available correlations in the literature. The effects of Dean number, rib size and particle volume fraction on the heat transfer coefficient and pressure drop have been examined. Results show that nanoparticles can increase the heat transfer coefficient considerably. For any fixed Dean number, relative heat transfer rate (The ratio of the heat transfer coefficient in case the of ?- Al2o3/ water nanofluid to the base fluid) increases as the particle volume fraction increases; however, the addition of nanoparticle to the base fluid is more useful for low Dean numbers. In the case of water flow, results indicate that the ratio of heat transfer rate of ribbed duct to smooth duct is nearly independent of Dean number. Noticeable heat transfer enhancement, compared to water flow in smooth duct, can be achieved when ?-Al2O3/ water nanofluid is used as the working fluid in ribbed duct.

Effects of Particle Concentration on the Partitioning of Suspensions at Small Divergent Bifurcations

1996 ◽  
Vol 118 (3) ◽  
pp. 287-294 ◽  
Author(s):  
R. Ditchfield ◽  
W. L. Olbricht
Keyword(s):  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Diameter ◽  
Circular Cross Section ◽  
Experimental Results ◽  
Hydrodynamic Interactions ◽  
Spherical Particles ◽  
Straight Tube ◽  
Particle Volume ◽  
Reynolds Number Flow

Experimental results are reported for the low Reynolds number flow of a suspension of spherical particles through a divergent capillary bifurcation consisting of a straight tube of circular cross-section that splits to form two tubes of equal diameter. The partitioning of particles between the downstream branches of the bifurcation is measured as a function of the partitioning of total volume (particles + suspending fluid) between the branches. Two bifurcation geometries are examined: a symmetric Y-shaped bifurcation and a nonsymmetric T-shaped bifurcation. This experiment focuses on the role of hydrodynamic interactions between particles on the partitioning of particles at the bifurcation. The particle diameter, made dimensionless with respect to the diameter of the branch tubes, ranges from 0.4 to 0.8. Results show that hydrodynamic interactions among the particles are significant at the bifurcation, even for conditions where interactions are unimportant in the straight branches away from the bifurcation. As a result of hydrodynamic interactions among particles at the bifurcation, the partitioning of particles between the branches is affected for particle volume fractions as small as 2 percent. The experimental results show that the effect of particle volume fraction is to diminish the inhomogeneity of particle partitioning at the bifurcation. However, the magnitude of this effect depends strongly on the overall shape of the bifurcation geometry, and, in particular on the angles between the branches.

Fluid Flow Through Randomly Packed Monodisperse Fibers: The Kozeny-Carman Parameter Analysis

1997 ◽  
Vol 119 (1) ◽  
pp. 188-192 ◽  
Author(s):  
O. Rahli ◽  
L. Tadrist ◽  
M. Miscevic ◽  
R. Santini
Keyword(s):  
Fluid Flow ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Experimental Results ◽  
Parameter Analysis ◽  
Flow Through Porous Media ◽  
Aspect Ratios ◽  
A Value ◽  
Flow Through ◽  
Permeability Increase

Experimental studies have been carried out on fluid flow through porous media made up of randomly packed monodisperse fibers. The permeability and the Kozeny-Carman parameter kk are deduced from experimental results. The variations of the permeability increase exponentially with the porosity. The parameter kk is a decreasing function of the porosity ε and tends asymptotically to a value close to that deduced from a modified Ergun relation. The important decrease, observed for small aspect ratios, is certainly an effect of the cut sections of fibers. The results in terms of parameter kk are systematically compared to those deduced from various theoretical models. The variation laws of the parameter kk, deduced from different models, present important discrepancies with our experimental results.

Biomechanics of Growth, Remodeling, and Morphogenesis

1995 ◽  
Vol 48 (8) ◽  
pp. 487-545 ◽  
Author(s):  
Larry A. Taber
Keyword(s):  
Shape Change ◽  
Experimental Studies ◽  
Cell Movement ◽  
Theoretical Models ◽  
Cellular Level ◽  
Experimental Results ◽  
Future Research ◽  
Cell Sheets ◽  
Biomechanical Models ◽  
Division Cell

This review deals with biomechanical aspects of growth (mass change), remodeling (property change), and morphogenesis (shape change) in living systems. The emphasis is on theoretical models, but relevant experimental results also are discussed. As an aid to the reader, the fundamental biological terms and concepts are defined for the general problem and for each specific topic. At the outset, the processes involved in growth, remodeling, and morphogenesis are described and placed within the context of the evolution of species. Next, some of the analytical methods used in biomechanical models for these processes are presented. Then, applications of these and other techniques to specific systems are discussed, beginning at the cellular level and proceeding upward to the tissue and organ levels. At the cellular level, modeling and experimental studies are reviewed for cell division, cell movement, and pattern formation, and then morphogenetic mechanisms for epithelia (cell sheets) are discussed. At the tissue and organ levels, the musculoskeletal and cardiovascular systems are considered. Several models are described for growth, remodeling, and morphogenesis of bone, and mainly experimental results are examined in the cases of skeletal muscle, the heart, and arteries. Specific topics for the cardiovascular system include hypertrophy, residual stress, atherosclerosis, and embryonic development. Finally, some future research directions are suggested.

scholarly journals Heat transfer studies of Al2O3/water-ethylene glycol nanofluid using factorial design analysis

2021 ◽  
pp. 21-21
Author(s):  
Srinivasan Manikandan ◽  
Nesakumar Dharmakkan ◽  
Nagamani Sumana
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Ethylene Glycol ◽  
Transfer Coefficient ◽  
Heat Input ◽  
Base Fluid ◽  
Volume Fraction ◽  
Nanoparticle Volume Fraction ◽  
Experimental Heat ◽  
Fluid Concentration

The experimental study of heat transfer coefficient of nanofluid plays a significant role in improving the heat transfer rate of the heat exchanger. The research was conducted in a natural convection heat transfer apparatus by suspending Al2O3 nanoparticle in a base fluid of Water-Ethylene glycol mixture. The effects of heat input (A), nanoparticle volume fraction (B), and base fluid concentration (C) on experimental heat transfer coefficient (hexpnf) were studied. By the results obtained by MINITDesign software 23 full factorial design matrix, 16 experimental runs were performed with the lower and higher level of input factors. The levels for heat input are 10 and 100 W; nanoparticle volume fraction is 0.1 and 1 volume% and for base fluid concentration is 30 and 50 volume% of Ethylene Glycol in water. From the obtained experimental results residual plots, Pareto chart, contour plot and 3D surface plots were drawn. It can be found from the study that the experimental heat transfer coefficient showed highest enhancement with high level of nanoparticle volume fraction and moderate enhancement with high level of heat input and slight enhancement with base fluid concentration.

Effective Viscosity Measurement of CuO and ZnO Nanofluids

2009 ◽  
Author(s):  
Dale A. McCants ◽  
M. Yakut Ali ◽  
Jamil Khan
Keyword(s):  
Heat Transfer ◽  
Effective Viscosity ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Theoretical Models ◽  
Experimental Results ◽  
Transfer Performance ◽  
Increase With Increase ◽  
Zno Nanofluids ◽  
Thermo Physical Properties

Nanofluid has the promising potential for enhancing the heat transfer performance of conventional fluids. Several experimental and numerical attempts have been made earlier to investigate its important thermo physical properties like thermal conductivity and viscosity. The findings and results are quite disperse instead of reaching a definitive agreement. This paper presents effective viscosity measurements of CuO and ZnO nanofluids experimentally. A Brookfield viscometer model DV-I Prime with a CPE 40 cone has been used to determine the effective viscosity of nanofluids. The measurements have included the effect of volume concentration of nanoparticles and temperature. The experimental results are compared with several experimental and theoretical models available in the existing literature. From the obtained experimental results it can be concluded that the viscosity values of the above mentioned nanofluids has a tendency to increase with increase of nanoparticle concentration and follows a decreasing trend with an increase in temperature. Presented results can be used to define the above mentioned nanofluids within the experimental volume concentration range in CFD software package and hence to predict overall heat transfer performance using these nanofluids.

Optimization of Anhydrous Coolant’s Base Fluid and the Evaluation of Low Temperature Performance

2014 ◽  
Vol 696 ◽  
pp. 53-56 ◽  
Author(s):  
Jin Mao Chen ◽  
Bo Gao ◽  
Guan Jun Leng ◽  
Jing Heng Feng
Keyword(s):  
Low Temperature ◽  
Ethylene Glycol ◽  
Propylene Glycol ◽  
Base Fluid ◽  
Evaluation Method ◽  
Freezing Point ◽  
Reference Value ◽  
Experimental Results ◽  
Temperature Performance ◽  
Low Temperature Performance

The low-temperature viscosity of anhydrous coolant is reduced by adding ethylene glycol to the propylene glycol base fluid, and the evaluation method of low-temperature fluidity is also studied. The experimental results show that the low-temperature fluidity of anhydrous coolant can be greatly improved by the participating of ethylene glycol. Freezing point method is usually used for measuring the low temperature performance of coolant, but for “long icing process” anhydrous coolant, beginning-crystal point shows more practical reference value. Therefore, freezing point, beginning-crystal point and low-temperature fluidity should be considered at the same time when evaluation the low temperature performance of anhydrous coolant.

The Investigation of Proppant Particle-Fluid Flow in the Vertical Fracture with a Contracted Aperture

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Hai Qu ◽  
Rui Wang ◽  
Xiang Ao ◽  
Ling Xue ◽  
Zhonghua Liu ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Volume Fraction ◽  
Particle Density ◽  
Particle Volume Fraction ◽  
Experimental Results ◽  
Fluid Viscosity ◽  
Flow Conditions ◽  
Particle Volume ◽  
Proppant Transport ◽  
Bed Height

Summary Proppant placement plays a crucial role in maintaining the conductivity of fractures after a hydraulic fracturing treatment. The process involves the transport of particles by fluid flow in complex fractures. Many studies have focused on proppant transport and distribution in the fracture with a constant aperture, but relatively few studies have investigated the proppant-fluid flow in a vertical fracture with a contracted aperture. In this work, we examine experimentally proppant transport in a fracture with a contracted aperture. The objective is to evaluate the distribution of particle beds in the contracted fracture at different flow conditions. In this paper, particle-fluid flow in the contracted fracture is studied experimentally by a laboratory size slot. A planar slot with a constant width is used to benchmark the experimental results, and a published correlation validates the bed equilibrium heights in the planar slot. Six types of particles are chosen to simulate the effects of particle density and size. The proppant distribution is evaluated by the bed height when the bed reaches the equilibrium states. The effects of fluid velocity, fluid viscosity, particle density, particle size, and particle volume fraction on particle distribution are investigated. The results confirm that the proppant particle-fluid flow in the contracted slot is more complicated than that in the planar slot. The phenomena of particle vortices and resuspension were observed at the contraction of the cross-section. The shape on the top of the bed is like a descending stair in which the height gradually decreases in the length direction. The bed height in the contracted slot is lower and more irregular than that in the planar slot at the same flow conditions. Smaller sands injected at a high flow rate and fluid viscosity can form a lower bed. The trend would be reversed by using denser particles and high particle volume fraction. A reliable model expressed by four dimensionless numbers is developed by the linear regression method for predicting the bed equilibrium height. The model and experimental results provide directions to quantitatively evaluate the particle transport and distribution in a fracture with a contracted aperture.

Sign in / Sign up

Export Citation Format

Share Document