EFFECT OF CONCENTRATION OF MAGNETIC PARTICLES ON FERROOIL’S DYNAMIC VISCOSITY AS A FUNCTION OF TEMPERATURE AND SHEAR RATE

2015 ◽  
Vol 19 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Marcin Frycz
Keyword(s):  
Shear Rate ◽  
Dynamic Viscosity ◽  
Magnetic Particles

Influence of Fillers on the Viscosity Properties of One-Pack Polyurethane Sealants

2021 ◽  
Vol 410 ◽  
pp. 605-610
Author(s):  
Kseniya A. Timakova ◽  
Yuriy T. Panov ◽  
Evgeniy A. Timakov
Keyword(s):  
Shear Rate ◽  
Dynamic Viscosity ◽  
Sharp Increase ◽  
Sharp Decrease ◽  
Shear Forces ◽  
Complex Orientation ◽  
Developed Surface ◽  
Mineral Fillers ◽  
Constant Shear Rate ◽  
Shape Of Particles

The paper investigates the effect of fillers on the viscosity properties of one-pack polyurethane sealants. It is noted that with the introduction of such mineral fillers as Mikarb, Midol, MTD2 chalk and aluminum hydroxide, the dynamic viscosity of the composition increases uniformly, while when filled with chemically precipitated Calofort SV chalk and MT-GShM talc, an abnormally sharp increase in viscosity is observed. Such an increase in viscosity for Calofort SV is explained by a highly developed surface, in contrast to other fillers. Talc is characterized by a plate-like shape of particles, which leads to a complex orientation of talc particles in the composition and shear difficulties.It was found that a sealant filled with chemically precipitated chalk has more than 100 pts. wt.(parts by weight), per 100 pts. wt. of the prepolymer under the influence of shear forces (at a constant shear rate) during the first 10 minutes of exposure, a sharp decrease in viscosity is observed, which is characteristic of thixotropic compositions, reaching a constant value after 5-10 minutes. After 10 minutes, the thixotropy of the sealant is restored. Talc does not impart thixotropic properties to the sealant composition.

Viscosity in Exploitation Time Analysis of the Lubricating Oil Used in the Combustion Engine of the Personal Car

2015 ◽  
Vol 220-221 ◽  
pp. 271-276 ◽  
Author(s):  
Grzegorz Sikora ◽  
Andrzej Miszczak
Keyword(s):  
Shear Rate ◽  
Dynamic Viscosity ◽  
Combustion Engine ◽  
High Shear Rate ◽  
Engine Oil ◽  
Lubricating Oil ◽  
High Shear ◽  
Oil Viscosity ◽  
Peltier Element ◽  
Engine Model

The aim of this study is to develop a mathematical model of the lubricating oil viscosity changes during the exploitation time of the engine.The aim was achieved by measurements of dynamic viscosity of engine oil used in a passenger car Volkswagen Touran equipped with a turbocharged diesel engine with a capacity of 2.0 liters. The recommended interval for oil change in this engine model is 30000 km. Oil used in this study was Shell Helix AV-L (viscosity grade SAE 5W30, designation VW: 50700).Viscosity tests were made on a Haake MARS III using two measuring systems. The first consisted of a plate-cone system with Peltier element for temperature stabilization. The second one is the high shear rate chamber with temperature control thermostat co-operating with ultra-A40 AC200 which can operate at temperatures ranging from-40 °C to +200 °C. The high shear rate chamber, consisting of a measuring cylinder and the rotor, the shear rate can achieve up to 200000 s–1.Dynamic viscosity measurements were performed at temperatures ranging from 20 °C to 90 °C.The results of the research are shown in the graphs and in tabular form. Obtained graphs made it possible to determine characteristics of the oil ageing for each mileages, temperatures and shear rates.

scholarly journals Rheological characteristics of aluminium oxide (AL2O3) based nanolubricant

2020 ◽  
Vol 39 (2) ◽  
pp. 424-432
Author(s):  
M. Ogbonnaya ◽  
O.O. Ajayi ◽  
M.A. Waheed
Keyword(s):  
Shear Rate ◽  
Exponential Function ◽  
Dynamic Viscosity ◽  
Mass Concentration ◽  
Aluminium Oxide ◽  
Al2o3 Nanoparticles ◽  
Step Method ◽  
Rheological Measurement ◽  
Linear Fit ◽  
The Relationship

This paper presents the rheological measurement of aluminium oxide (Al2O3) nanolubricant. The nanolubricant was prepared using the two-step method from dry Al2O3 nanoparticles and Capella D lubricant as base fluid. The dynamic viscosity of the Al2O3 nanolubricant at constant shear rate was measured at atmospheric pressure in the temperature range of 278 K to 323 K for pure based lubricant along with nanolubricant mass concentration of 1%, 2% and 4% with nanoparticle size of 10 nm, 20-30 nm and 80 nm. The measured data was analysed using the linear fit and exponential function fit. The result showed that at constant particle size and concentration, the dynamic viscosity reduces with increase in temperature while at constant temperature, the viscosity increased with nanoparticle concentration. The exponential function fit regression best describe the relationship between the viscosity and temperature when compared with the linear fit regression while the polynomial function fit best describe the relationship between the viscosity and mass concentration. Keywords: Dynamic viscosity, nanolubricant, shear rate, regression, concentration, temperature

Effect of the Concentration of the Magnetic Particles in the Ferrooil on its Dynamic’s Viscosity Changes in an External Magnetic Field

2015 ◽  
Vol 220-221 ◽  
pp. 324-327 ◽  
Author(s):  
Marcin Frycz ◽  
Wojciech Horak
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Tribological Properties ◽  
Dynamic Viscosity ◽  
Magnetic Particles ◽  
Magnetic Polarity ◽  
Journal Bearings ◽  
Physical Conditions ◽  
Viscosity Changes

There is presented an effect of the changes of the concentration of magnetic particles included in the ferrooil on the dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. In that way, the influence of external physical conditions of ferrooil’s employment was also taken into account. Ferrooil’s dynamic viscosity changes significantly alter the tribological properties and thus its usefulness as a lubricant of the sliding journal bearings. Due to the fact that the ferrooil demonstrates strong magnetic polarity in the presence of an external magnetic field, it is possible to control the viscosity by means of an external magnetic field just by changing the intensity as well as by changing of the concentration of magnetic particles.The paper presents, in the form of graphs, the changes of ferrooil’s dynamic viscosity as a function of temperature and concentration of magnetic particles. The results of research were also subjected to analysis.

RESEARCHING AND MODELING OF THE DYNAMIC VISCOSITY OF THE FERRO-OILS WITH THE DIFFERENT CONCENTRATIONS OF MAGNETIC PARTICLES IN THE ASPECT OF PRESSURE CHANGES

Tribologia ◽  
2018 ◽  
Vol 272 (2) ◽  
pp. 39-48 ◽  
Author(s):  
Marcin FRYCZ
Keyword(s):  
Experimental Research ◽  
Dynamic Viscosity ◽  
Magnetic Particles ◽  
Pressure Change ◽  
Pressure Chamber ◽  
Physical Models ◽  
Shear Rates ◽  
Pressure Changes

In this article, the results of the experimental research of determining the dynamic viscosity of the ferro-oils with different concentration of the magnetic particles in terms of pressure change are presented. The research was conducted on the Thermo Scientific Haake Mars III rheometer in the configuration with a pressure chamber. The applied configuration allowed the author to conduct research on the change of viscosity for the selected pressure values p in range from 0 to 100 bars. The research was conducted for three selected temperature values, including t = 30°C, 60°C, and 90°C, as well as selected shear rates of 200 and 600s-1. The chosen concentration values of the magnetic particles were nCS = 1%, 2%, 4%, 6%, and 8%. The viscous characteristics gathered as a result of the research have been analysed with the aim of identifying the nature of the correlations and to create mathematical-physical models of changes in the dynamic viscosity of the ferrooils due to the change in pressure in terms of concentrations of the magnetic particles. Analysis, identification, and adaptation of the characteristics were conducted using the StatSoft STATISTICA ver. 9 software. Selected mathematical adaptations of the acquired results were submitted through the enhanced analysis. In addition, parameters of the course of functions were designated and their qualitative assessments were made.

scholarly journals Rheological properties of traditional balsamic vinegar: New insights and markers for objective and perceived quality

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Pasquale M. Falcone ◽  
Elisa Sabatinelli ◽  
Federico Lemmetti ◽  
Paolo Giudici
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Dynamic Viscosity ◽  
Flow Instability ◽  
Relaxation Times ◽  
Sensory Properties ◽  
Flow Behaviour ◽  
Shear Rates ◽  
Wide Range ◽  
Balsamic Vinegar

The molecular structure of Traditional Balsamic Vinegar (TBV) undergoes shear-induced and time-dependent jamming transitions due to the high solute concentration and self-assembling phenomena of high molecular size melanoidins with very-long relaxation times (12 years at least or more than 25). The purpose of this work was to perform a descriptive and quantitativeevaluation of relationships between rheological properties, vinegar composition, and perceptual assessment of sensory properties according to the official sensory procedure. With this aim, vinegars having quality traits matching legal requirements for the PDO designation were analyzed for their reducing sugars (glucose and fructose), volatile acidity, fixed acidity, pH, Brix degree, and density as well as for their flow behaviour and dynamic viscosity over a wide range of shear rates. Results showed that flow behaviour of TBV was affected by jamming properties over wide-scale ranges of shear rate producing flow instability below a shear rate of 60s-1. Homogeneous, continuous flow was found at medium-high shear rates with thickening and/or thinning traits. A common onset for the structure scaling was mathematically estimated to occur close to when the density was 1.32 gmL-1. Comparative analysis of rheological, compositional and sensory properties suggested that the colloidal jamming of the vinegar melanoidins dominated the total olfactive and gustative stimuli, and determined the classification of the vinegars that had a higher dynamic viscosity but more homogeneous flow as being of the highest commercial quality category. A robust statistical model was proposed encoding for the top-down decision-making process for quality assignment according to the official sensory procedure, using composition and flow properties as predictor variables. 

scholarly journals Characteristic of selected rheological parameters of stallion ejaculate

2008 ◽  
Vol 51 (1) ◽  
pp. 16-22
Author(s):  
L. Severa ◽  
L. Máchal ◽  
I. Křivánek ◽  
M. Machatková ◽  
O. Mamica
Keyword(s):  
Shear Rate ◽  
Dynamic Viscosity ◽  
Sperm Concentration ◽  
Shear Thinning ◽  
Experimental Series ◽  
Time Dependent ◽  
Rheological Parameters ◽  
Average Value

Abstract. Dynamic viscosity of native (30 minutes after ejaculation) and 24 hours stored (at 4 °C) stallion ejaculate was measured. The ejaculate from 10 breeding stallions was examined in three different experimental series. The average value of dynamic viscosity at shear rate 1.02 s−1 was found to be 416.8 ± 10.1 mPa.s. The correlation between ejaculate volume, sperm concentration and viscosity was tested. The experiments resulted in finding a dependence between increasing viscosity and decreasing sperm concentration (rp = −0.67; P<0.05). Performed experiments with changing shear rate demonstrated non-Newtonian characteristics of stallion ejaculate with a clear shear-thinning behaviour. Stallion ejaculate appeared to be slightly time-dependent liquid.

scholarly journals Study Rheological Behavior of Rapeseed Oils Compared to Mineral Oil

2021 ◽  
Vol 37 (1) ◽  
pp. 247-249
Author(s):  
Ioana Stanciu
Keyword(s):  
Shear Rate ◽  
Rheological Behavior ◽  
Dynamic Viscosity ◽  
Rapeseed Oil ◽  
Mineral Oil ◽  
Dynamic Shear ◽  
Dynamic Temperature ◽  
Biodegradable Lubricant

This article presents the dependence of dynamic temperature viscosity and shear rate for rapeseed oils used as biodegradable lubricant and SAE 10W. The studied rheograms show the dependence of the dynamic shear rate viscosity as well as the dependence of the dynamic temperature viscosity. From the rheograms there is a decrease in the dynamic viscosity with temperature and shear rate for the two oils. The dynamic viscosity of rapeseed oil is most strongly influenced by the shear rate compared to the studied SAE 10W oil. The rheological behavior of rapeseed and mineral oil SAE 10W was studied with the Haake VT 550 viscometer at temperatures between 40 and 1000C.

scholarly journals Viscosity and Rheological Properties of Graphene Nanopowders Nanofluids

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 979
Author(s):  
Abderrahim Bakak ◽  
Mohamed Lotfi ◽  
Rodolphe Heyd ◽  
Amine Ammar ◽  
Abdelaziz Koumina
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Dynamic Viscosity ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Heat Extraction ◽  
Rheological Characterization ◽  
Shear Rates ◽  
Rheological Measurements

The dynamic viscosity and rheological properties of two different non-aqueous graphene nano-plates-based nanofluids are experimentally investigated in this paper, focusing on the effects of solid volume fraction and shear rate. For each nanofluid, four solid volume fractions have been considered ranging from 0.1% to 1%. The rheological characterization of the suspensions was performed at 20 ∘C, with shear rates ranging from 10−1s−1 to 103s−1, using a cone-plate rheometer. The Carreau–Yasuda model has been successfully applied to fit most of the rheological measurements. Although it is very common to observe an increase of the viscosity with the solid volume fraction, we still found here that the addition of nanoparticles produces lubrication effects in some cases. Such a result could be very helpful in the domain of heat extraction applications. The dependence of dynamic viscosity with graphene volume fraction was analyzed using the model of Vallejo et al.

scholarly journals Study rheological behavior of refined rapeseed oil

2020 ◽  
Vol 2 (2) ◽  
pp. 20-24
Author(s):  
Ioana Stanciu
Keyword(s):  
Shear Rate ◽  
Constant Temperature ◽  
Rheological Behavior ◽  
Dynamic Viscosity ◽  
Rapeseed Oil ◽  
Refining Process ◽  
Shear Rates ◽  
Lower Viscosity ◽  
Viscosity Dependence

Extracted from rapeseed oil was subjected to purification and refining process and then characterized in terms of rheological, ie dynamic viscosity dependence study in terms of speed shear constant temperature. The results show that at 400C, 600C, 800C and 900C dynamic viscosities of oil decreases with shear rate. At higher shear rates of 20s-1 shows lower viscosity oil fluctuations, became almost constant.  

Sign in / Sign up

Export Citation Format

Share Document