Viscosity-temperature Characteristics Research Articles

Understanding Ash Fusion and Viscosity Variation from Coal Blending Based on Mineral Interaction

The ash-fusion and viscosity–temperature characteristics (AFV) of three typical coals [high-silica–alumina Changzi coal (CZ), high-calcium Hebi coal (HB), and high-iron Zhaolou coal (ZL)] and their mixtures were analyzed, and the AFV variation mechanism by blending was investigated. Each of the three coals is unsuitable for entrained-flow gasification. With an increasing HB mass ratio, the CZ mixture ash-fusion temperature (AFT) decreased (0–30%) and then increased slowly (>30%) and the critical-viscosity temperature (Tcv) decreased (0–40%) and then increased (>40%). With an increase in the ZL mass ratio, the AFT and Tcv decreased gradually. For the CZ mixture entrained-flow gasification, the appropriate blending ratios of HB and ZL were 20–60 and 60–100%, respectively. The AFV characteristics were determined from the mineral and amorphous matter contents through the interaction and evolution of different minerals. The formation of low-melting-point minerals (e.g., anorthite, gehlenite, and hercynite) and...

Numerical analysis for viscosity temperature characteristics of abrasive flow finishing on micro-bore nozzle

Abrasive flow machining has become an efficient and economical ultra precision process for machining micro-bore parts. In this paper, aiming at viscosity temperature characteristics of abrasive flow finishing on micro-bore nozzle, under the guidance of the three governing equations of fluid mechanics theory, mixed phase model and discrete phase model were conducted, FLUENT software was resorted to simulate the discrete and fluid phase numerical characteristics of the solid-liquid two-phase flow field in the nozzle orifice with various field temperature and viscosity of slurry, the mechanism of erosion and wear of particles and effect of different processing parameters on particle erosion rate were uncovered, which provides a theoretical basis for the nozzle structure of abrasive flow machining.

Numerical analysis in viscosity-temperature characteristics of solid-liquid two-phase abrasive flow polishing

The non-linear tube is widely used in military and civil fields and the general performance of the machine depends on the internal channel surface quality of it. The effective ways to improving the surface quality is solid-liquid two-phase abrasive flow polishing technology. So, the numerical analysis about the internal channel of non-linear tube polished by abrasive flow is implemented to analyze the effect of viscosity-temperature characteristics of abrasive flow polishing on the internal channel surface quality. Turbulent kinetic energy, intensity and viscosity, nephogram of the dynamic pressure distribution, and corresponding relation of temperature and turbulent kinetic energy, near the wall of non-linear tube, are received from the simulation in different initial turbulent kinetic energy and temperature which provides a theoretical basis for controlling the surface quality.

High-Performance Lubricant Base Stocks from Biorenewable Gallic Acid: Systematic Study on Their Physicochemical and Tribological Properties

Synthesis, characterization, and evaluation of a series of gallate derivatives as lubricant base stocks are described. The gallate derivatives were synthesized via sequential esterification and alkylation reactions from biorenewable raw material gallic acid. All the synthesized gallate derivatives were structurally characterized by using NMR, IR, and HRMS spectral data. Their physicochemical and lubricating properties including density, viscosity, viscosity index, pour point, flash point, volatility, corrosion level, thermal and oxidation stability, and friction-reducing and antiwear properties were systematically investigated. On the basis of the physicochemical and lubricating data, it can be concluded that gallate derivatives have good properties in terms of viscosity–temperature characteristics, corrosion ability, volatility, and low-temperature flow ability. More important, they have predominant thermal and oxidation stability, as well as high-temperature friction-reducing and antiwear performances compared with the existing synthetic ester oils. These favorable technical performances together with their biological available resources recommend gallate derivatives as excellent base stocks for the development of high-performance green lubricant products.

Aquathermolysis of heavy oil using nano oxides of metals

The effect of suspended nanoparticles of magnetite and hematite on thermal decomposition of heavy oil at a temperature of 360°C in a vapor medium at different system pressures is revealed. The preferential destruction reactions of macromolecular components of oil, which lead to the reduction of oil viscosity, are established. The effect of zinc and aluminum oxides as additives initiating cracking of hydrocarbon bonds is studied. The changes in structure of the component of the converted products, as compared to the original crude oil, are obtained. Conducting the process in the presence of additives at a pressure of 11MPa led to the reduction of the aromaticity of the final products, increase in the yield of hydrocarbon oils and the formation of gaseous products. It is observed that the amount of asphalt-resinous substances is reduced as the result of their conversion in the presence of additives. Rheological curves of conversion products are obtained, based on them the peculiarities of viscosity-temperature characteristics change can be shown.

Research on electrostatic coalescence of water-in-crude-oil emulsions under high frequency/high voltage AC electric field based on electro-rheological method

The viscosity–temperature characteristics and phase inversion point as well as the chord lengths distribution of dispersed droplets have been investigated. The relative viscosity reduction is then effectively taken as the evaluation means to investigate the effects of shear rate, electric field strength, frequency, voltage waveform, and initial water cut on the electrocoalescence efficiency experimentally systematically. It is determined that the phase inversion point is located between 35%–45%. The chord lengths of dispersed droplets are concentrated in range of 10–150μm and the average value is 61.3μm for the water-in-crude-oil emulsions sample. We found that the coalescence efficiency can be improved by increasing shear rate to some extent while keeping other parameters unchanged, but decreased instead with the shear rate exceeding 50s−1, which suggests that only the appropriate flow shear condition can help to promote the electrostatic coalescence. Meanwhile, the present work has demonstrated that there exists optimum electric field strength(8kV/cm) and frequency(2kHz) for the given water-in-crude-oil emulsions, and the ranking of three voltage waveforms in decreasing order of coalescence efficiency is AC square, triangular and sinusoidal waveform. In addition, with the three kinds of voltage waveforms, the coalescence efficiency are all significantly improved as the water cut increases from 10% up to 40%, which demonstrates the good performance of high frequency/high voltage electric field for treating crude oil emulsions with high water cut.

Steam – Air Conversion of Heavy Oil in the Presence of Nanosized Metal Oxide Particles

The effect of suspended nanosized magnetite and hematite particles on the thermal degradation of heavy oil at 360°C in a steamair atmosphere was studied at various pressures. The highmolecularweight components of the oil were found to undergo degradation, leading to reduced oil viscosity. The effect of aluminum and zinc oxides used as additives to initiate hydrocarbon bond dissociation on this process was also investigated. The mechanisms for how change in composition components alters the conversion products relative to the initial oil were studied. Carrying out the process in the presence of additives at 11 MPa leads to reduced yield of aromatic end products with increased yield of oil hydrocarbons and the formation of gaseous products. Asphalticresin materials are also found to be reduced due to conversion in the presence of the additives. Rheological curves were determined for the conversion products and were used to show the change in the viscositytemperature characteristics.

Research on the rheological properties of a perfluoropolyether based ferrofluid

A perfluoropolyether based ferrofluid was prepared using co-precipitation method and the rheological properties of the ferrofluid were studied by a rotational rheometer. A series of experiments were designed to study the influence of magnetic field, shear rate and temperature on the magnetoviscous effect of the perfluoropolyether based ferrofluid. Consecutive measurements of the megnetoviscous parameter with the temperature-increasing process were made and totally different tendency of the curves was observed under a range of shear rates. The magnetic field strength influence on the observed temperature dependencies was also studied experimentally. A discussion on the different mechanisms of the influence of temperature on magnetoviscous effect is presented based on the chain model of magnetic particles and the viscosity-temperature characteristics of the base carrier liquid.

A new asperity interaction model considering transient flash temperature and inhomogeneous distribution of oil viscosity

A momentary contact of asperities will generate transient flash temperature phenomena in boundary lubrication. According to the viscosity–temperature characteristics of lubricant, the inhomogeneous distribution of temperature during the process of asperity contact would cause the inhomogeneous distribution of oil viscosity. This paper proposes a coupled Eulerian–Lagrangian based approach to analyze the influence of inhomogeneous distribution of viscosity on the friction coefficient of an asperity junction. The asperity interaction in boundary lubrication with different sliding velocities and different degrees of overlap of the undeformed surfaces were taken into account. Simulation results showed that the friction coefficient is proportional to the overlap and inversely proportional to sliding velocity. The results also showed that the influence of inhomogeneous distribution of oil viscosity on friction coefficient in boundary lubrication is limited.

In situ catalytic upgrading of heavy crude oil through low-temperature oxidation

The low-temperature catalytic oxidation of heavy crude oil (Xinjiang Oilfield, China) was studied using three types of catalysts including oil-soluble, water-soluble, and dispersed catalysts. According to primary screening, oil-soluble catalysts, copper naphthenate and manganese naphthenate, are more attractive, and were selected to further investigate their catalytic performance in in situ upgrading of heavy oil. The heavy oil compositions and molecular structures were characterized by column chromatography, elemental analysis, and Fourier transform infrared spectrometry before and after reaction. An Arrhenius kinetics model was introduced to calculate the rheological activation energy of heavy oil from the viscosity–temperature characteristics. Results show that the two oil-soluble catalysts can crack part of heavy components into light components, decrease the heteroatom content, and achieve the transition of reaction mode from oxygen addition to bond scission. The calculated rheological activation energy of heavy oil from the fitted Arrhenius model is consistent with physical properties of heavy oil (oil viscosity and contents of heavy fractions). It is found that the temperature, oil composition, and internal molecular structures are the main factors affecting its flow ability. Oil-soluble catalyst-assisted air injection or air huff-n-puff injection is a promising in situ catalytic upgrading method for improving heavy oil recovery.

CO2-triggered gelation for mobility control and channeling blocking during CO2 flooding processes

CO2 flooding is regarded as an important method for enhanced oil recovery (EOR) and greenhouse gas control. However, the heterogeneity prevalently distributed in reservoirs inhibits the performance of this technology. The sweep efficiency can be significantly reduced especially in the presence of “thief zones”. Hence, gas channeling blocking and mobility control are important technical issues for the success of CO2 injection. Normally, crosslinked gels have the potential to block gas channels, but the gelation time control poses challenges to this method. In this study, a new method for selectively blocking CO2 channeling is proposed, which is based on a type of CO2-sensitive gel system (modified polyacrylamide-methenamine-resorcinol gel system) to form gel in situ. A CO2-sensitive gel system is when gelation or solidification will be triggered by CO2 in the reservoir to block gas channels. The CO2-sensitivity of the gel system was demonstrated in parallel bottle tests of gel in N2 and CO2 atmospheres. Sand pack flow experiments were conducted to investigate the shutoff capacity of the gel system under different conditions. The injectivity of the gel system was studied via viscosity measurements. The results indicate that this gel system was sensitive to CO2 and had good performance of channeling blocking in porous media. Advantageous viscosity-temperature characteristics were achieved in this work. The effectiveness for EOR in heterogeneous formations based on this gel system was demonstrated using displacement tests conducted in double sand packs. The experimental results can provide guidelines for the deployment of the CO2-sensitive gel system for field applications.

Chemical Composition and Cold Flow Property of Cottonseed Oil Biodiesel Fuel

The Cottonseed oil methyl ester (COME) was prepared using an alkali catalyzed trans esterification reaction, and its chemical composition and cold flow properties (CFP) were studied. Two approaches, viz. blending with petrodiesel and treating with cold flow improver (CFI) were used to improve the CFP of COME. The results showed that COME was mainly composed of fatty acid methyl esters (FAMEs): C14:0–C22:0, C16:1–C20:1, C18:2 and C18:3–C20:3. The mass fractions of saturated and unsaturated FAMEs were 27.69% and 71.65%, respectively. The cold filter plugging point (CFPP) and kinematic viscosity (KV) at 40 °C of COME are -1 °C and 4.63 mm2/s respectively. Blending with -10 petrodiesel (-10PD) and 0 petrodiesel (0PD) can decrease the CFPP of COME/-10PD (B30-B40) and COME/0PD (B40-B50) -12 and -8 °C respectively. With the increase in petrodiesel content, the KV at 40 °C of blending oil decreased, and viscosity-temperature characteristics of blending oil were improved. When used Flow Fit (≤3vol.%), the CFPPs were reduce from COME/-10PD B5, B7, B10, B20, B50 and COME -8, -8, -9, -11, -11 and -1 °C to -28, -27, -26, -25, -16 and -5 °C respectively; COME/0PD -3, -3, -4, -5, -8 and -1 °C to -26, -25, -24, -24, -16 and -5 °C respectively.

Viscosity-temperature characteristics of warm mix asphalt binder with Sasobit®

Two matrix asphalt binders are used to prepare warm mix asphalt (WMA) binders with different dosages of Sasobit® additive, and the general technical properties, the dynamic viscosities at 60°C, the apparent viscosities above 110°C are measured and analyzed. It is found that the apparent viscosity exponentially decreases with the increase in temperature and could be considered as independent on shear rate. The dynamic viscosity exponentially increases with the increase in additive dosage, but the apparent viscosity linearly decreases. The WMA binder with more additives is more temperature susceptive, and the different effects of the additive on the viscosity-temperature characteristics is mainly because of the temperature transition point of the additive around 100–110°C. The additive improves both the high temperature property in serve stage and workability during construction. However, it worsens the low temperature property, which should be paid more attentions in practice.

A Green Technology Based Production of Bio-Lubricant for Future, Cleaner Environment from Non-Edible Oil of North East India-A Review

Depletion of the natural resources, the issue of food security and increased attention towards environmental issues have driven the lubricant industries to stimulate the development of non-edible oil-based material as bio-lubricant. The term bio-lubricant applies to all lubricants that are both rapidly biodegradable and non-toxic to human and aquatic environments. Conventional lubricants are prepared from mineral oil, which is a non-renewable resource. Non-edible oils with high oleic acid content are promising alternative as a bio-lubricant because of their excellent lubricacy, biodegradability, better viscosity-temperature characteristics and low evaporation loss. However, their use is restricted due to low thermal-oxidative stability and poor cold-flow behaviour. Combining genetic modification with chemical modification, the aim of substituting commercial lubricants from renewable resources can be achieved. This review highlights the production methods of bio-lubricants from native non-edible oils available in the North Eastern region of India, documenting the characteristics of the produced bio-lubricants along with a comparative analysis of different bio-lubricants produced.

Novel thermothickening lubricant with elastomeric nano-particles

Modified silicone oil with crosslinked silicon elastomeric nano-particles exhibits excellent viscosity–temperature characteristics.

The Abrasive Flow Machining Simulation of Common Rail Tube Holes Based on FLUENT

Based on the solid - liquid two-coupling theory, Use abrasive medium viscosity-temperature characteristics related to the mathematical model, using solid - liquid two-phase solution method Mixture models and standards, turbulence model combining with common rail pipe hole as the research object, choose different initial temperatures and processing procedures, numerical analysis was carried out on the flow channel wall temperature and turbulent kinetic energy. Using numerical analysis software FLUENT Abrasive Flow Machining rail tube orifice structure was three-dimensional numerical analysis; obtain a steady-state pressure, dynamic pressure, velocity, turbulent kinetic energy image, to study Abrasive Flow Machining process provides a theoretical basis and technical support.

Viscosity-Temperature Characteristic of Biodiesel Derived from Pistacia Chinensis Oil

The chemical compositions and viscosity-temperature characteristic of Pistacia Chinensis methyl ester (PCME) are investigated. Viscosity-temperature equations are proposed for predicting kinematic viscosity of PCME,PCME/0 petrodiesel (0PD) and PCME/-10 petrodiesel (-10PD) at different temperature. The objective is to show that PCME is mainly composed of fatty acid methyl esters of 14-24 even-numbered C atoms: C14:0-C24:0, C16:1-C22:1, C18:2-C20:2 and C18:3. The kinematic viscosity (40 °C) of PCME is 5.99mm2/s. PCME has higher kinematic viscosity and unfavorable viscosity temperature characteristic. An approach to reduce viscosity and enhance viscosity-temperature characteristic is put forward: blending with 0 PD or-10PD.

Facile synthesis of stable magnetic fluid using size-controlled Fe3O4 nanoparticles

Magnetic fluids based on superparamagnetic, well-crystalline and mono-dispersed Fe3O4 nanoparticles are synthesized by a facile thermal decomposition method. Low-cost Fe(oleate)3 is used as ferrous resource, and paraffin oil is introduced as solvent and carrier simultaneously. Fe3O4 nanoparticles with three kinds of different size (12, 16 and 20nm), exhibiting different saturation magnetization of 65.51, 68.03 and 74.48emu/g, respectively, are prepared easily by controlling the thermal decomposition time. Magnetic performance and viscosity-temperature characteristics of the magnetic fluid are also studied. It is found that the saturation magnetization of the magnetic fluid with 5% Fe3O4 mass percentage is 2.94emu/g, which exhibits a good viscosity temperature characteristics compared with paraffin carrier.

Mathematical model and experiment validation of fluid torque by shear stress under influence of fluid temperature in hydro-viscous clutch

The current design of hydro-viscous clutch(HVC) in tracked vehicle fan transmission mainly focuses on high-speed and high power. However, the fluid torque under the influence of fluid temperature can not be predicted accurately by conventional mathematical model or experimental research. In order to validate the fluid torque of HVC by taking the viscosity-temperature characteristic of fluid into account, the test rig is designed. The outlet oil temperature is measured and fitted with different rotation speed, oil film thickness, oil flow rate, and inlet oil temperature. Meanwhile, the film torque can be obtained. Based on Navier-Stokes equations and the continuity equation, the mathematical model of fluid torque is proposed in cylindrical coordinate. Iterative method is employed to solve the equations. The radial and tangential speed distribution, radial pressure distribution and theoretical flow rate are determined and analyzed. The models of equivalent radius and fluid torque of friction pairs are introduced. The experimental and theoretical results indicate that tangential speed distribution is mainly determined by the relative rotating speed between the friction plate and the separator disc. However, the radial speed distribution and pressure distribution are dominated by pressure difference at the lower rotating speed. The oil film fills the clearance and the film torque increases with increasing rotating speed. However, when the speed reaches a certain value, the centrifugal force will play an important role on the fluid distribution. The pressure is negative at the outer radius when inlet flow rate is less than theoretical flow, so the film starts to shrink which decreases the film torque sharply. The theoretical fluid torque has good agreement with the experimental data. This research proposes a new fluid torque mathematical model which may predict the film torque under the influence of temperature more accurately.

Vegetable oil-based ionic liquid microemulsions and their potential as alternative renewable biolubricant basestocks

This paper reports the successful formulation of microemulsions with vegetable oil as the continuous phase, room-temperature ionic liquid (IL) 1-butyl-3-methyl-imidazolium tetrafluoroborate as the polar phase, TritonX-100 as the surfactant, and 1-butanol as the cosurfactant. A pseudo-ternary phase diagram, dynamic light scattering data, UV–vis spectra, and kinematic viscosity measurements were employed to characterize and analyze the phase behavior and microstructure of the vegetable oil-based IL microemulsions. The tribological properties of the designed microemulsions were evaluated using a four-ball tester. The results confirmed the formation of an IL microemulsion containing vegetable oil. The designed petroleum-free microemulsions exhibit excellent viscosity-temperature characteristics and friction–reduction proprieties, indicating the tremendous potential of IL microemulsions as renewable biolubricant basestocks.