Dynamic Viscosity Coefficient Research Articles

ИССЛЕДОВАНИЕ ФИЗИКО-ХИМИЧЕСКИХ СВОЙСТВ РЫБНЫХ ФАРШЕЙ, СУХИХ РАСТИТЕЛЬНЫХ ПРЕМИКСОВ И ИХ СМЕСЕЙ

To provide efficient processing of fish assorted raw material (chilled or frozen) there have been studied the properties of formed combined fish and vegetable products. Pike perch and carp minced meat was chosen as samples for research, into which dry powder of white cabbage was added. The results of thermodynamic analysis of hygroscopic properties for determining the ratio of free and bound moisture in minced products have been presented. The obtained data prove that introduction of powdered premix leads to a decrease in free moisture in the mixture due to its partial binding by premix. The upper level of the content of the additive in the mixture is limited by sensory evaluation, because when this limit is exceeded, the indicators of the resulting semi-finished product may radically differ from the model sample. There are given the results of studying thermophysical properties of frozen objects at ordinary temperatures and below zero, structural and mechanical properties, in particular, density, conditional coefficient of effective dynamic viscosity, amount of frozen moisture, cryoscopic temperatures of cryopreservation objects. The established mathematical dependencies of the characteristics of products and concentrates can be used in engineering practice in the design of production processes and apparatuses in processing raw materials of animal and vegetable origin. The obtained research results are necessary for the scientific analysis of kinetics and dynamics of heat and mass exchange processes (cooling and freezing), their modeling and optimization for the purpose of energy and resource saving in processing food materials.

The numerical study of the effect of design parameters on EWOD actuation in microchannels of rectangular cross section

Electrowetting on Dielectric (EWOD) method is widely used to actuate microdroplets sandwiched between parallel plates in microfluidic chips. However, utilization of this method to transport liquid plugs in conduits has not been comprehensively studied to date. In this paper, the EWOD actuation of a liquid plug confined in a microchannel of rectangular cross section is numerically studied using OpenFoam. The effect of various parameters including electrowetting dimensionless number ( $$\eta $$ ), contact angle hysteresis (CAH), dynamic viscosity and surface tension coefficient on transport velocity is investigated by employing an interactive simulation approach. The transport velocity can be considered a gauge to evaluate the actuation efficiency. The results show that, increasing $$\eta $$ has a greater impact on velocity for larger values of CAH. In addition, it is shown that the average velocity increases linearly by increasing the surface tension coefficient. An inverse relationship between velocity and dynamic viscosity is also observed. These trends are in accordance with the theoretical model developed for a similar case in the literature. To estimate the maximum possible gap size between electrodes (MPGS), non-actuated distance travelled before the liquid plug comes to stop is evaluated. The results show that by decreasing the values of $$\eta $$ , the effect of changing CAH on MPGS becomes more substantial.

The research of the parameters of a vibration machine for composite materials compaction

Based on the analysis of the conventional methods for composite materials compaction, the authors propose a vibration machine made as a form without bottom with a horizontal oscillation vibro-exciter mounted on its end face. To determine the rational parameters of the vibration machine we researched the “vibration form – composite medium” dynamic system wherein composite medium is represented in the form of a system with distributed parameters. This system takes into account the resilient, viscous, inertia and power properties of the compacted composite material. We formulated a partial differential equation describing the variation of stresses in the compacted medium depending on the dynamic module of resilient deformation, the coefficient of dynamic viscosity, the coefficient of non-resilient resistance and the compacted medium inertia in the functional dependence on the composite material density and relative deformation. We formulated an oscillation wave equation describing the propagation of the viscous-resilient-plastic waves of deformation in the compacted composite material. The solution of the oscillation wave equation resulted in the formulation of the law of the oscillation of the form and the compacted material. We determined the stresses occurring in the composite material. We obtained the relations for the determination of the vibration machine basic parameters depending on the physical and mathematical characteristics of the compacted composite material.

Investigation of flow structure and heat exchange formation in corrugated pipes at transient reynolds numbers

The problem of convective heat transfer in the initial section of a pipe with a corrugated section was considered at transient Reynolds numbers. Influence on the intensity of heat exchange and the magnitude of hydraulic resistance of geometric parameters (wavelength and amplitude) of the corrugated insert, variability of the thermophysical properties of the heat carrier and the direction of the heat flow was estimated. Threshold value of the corrugation wavelength (L/R 0 >0.6) was determined for the Reynolds number range under consideration for which there was a significant growth of heat exchange. Influence of the gradient of the dynamic viscosity coefficient on flow stability and intensification of heat exchange in internal flows was demonstrated. Influence of Reynolds and Prandtl numbers on local heat transfer, hydraulic resistance and flow structure was determined. It was established that the use of corrugated surfaces is ineffective at Reynolds numbers less than 2000. It was shown that heat exchange in a pipe can be raised to 30 % with an increase in hydraulic resistance of 1.05 times in the range of Reynolds numbers 2·10 3 ...1.4·10 4 with the use of a nonencumbering corrugation.

Influence of surface active substances on the intensification of extraction when changing hydrodynamic indices of the technology of organopreparations

An influence of surface-active substances (SAS) on the change of physical characteristics of extractants of the group of organic preparations (chonsorid, heparin, and ronidase) was studied. Authors established rational concentrations of SAS in extractants, at which the minimum of coefficient of surface tension and the decrease in coefficient of dynamic viscosity are reached. For the solution of extractant of chonsurid – SAS butanol in the concentration of 0,05–0,06 % by weight, of heparin – butanol in the concentration of 0,5–0,6 % by weight, of ronidase – butanol in the concentration of 0,45–0,6 % by weight. Mean values of a near–surface laminar layer were established with the help of theoretical calculations, namely: for heparin – 1 mm, for chonsurid – 3 mm, for ronidase – 1 mm. Kinetics of extracting demonstrated an increase in the amount of the mass of extract when using extractants with SAS: for chonsurid – by 1,4 times, for heparin – by 1,7 times, for ronidase – by 1,9 times. Mathematical calculations proved a change in the similarity numbers under the influence of the surfactants, the Archimedean, Euler and Reynolds numbers were calculated and their values were compared. The Archimedean number changes its value for the extractants of chonsurid from 1028 to 10028, for those of heparin – from 3463 to 5910, for those of ronidase – from 990 to 6236. The value of the Reynolds number changes with the use of industrial extractants and the proposed extractants with the addition of SAS for chonsurid – from 18,6 to 91,6, for heparin – from 34,8 to 265, for ronidase – from 17,5 to 65,1. The Euler number with the use of industrial extractants for chonsurid is 170, for heparin – 92,2, for ronidase – 69,9, and when using the proposed extractants with the addition of SAS, it is: 37,5; 11,3; 12, respectively. Authors assessed hydrodynamic situation on the border of the contact “solid body – liquid” using the ratio of forces of surface tension to inertial forces on the basis of dimensionless set – surface number. Surface number changes its value when using industrial extractants and the proposed extractants with the addition of SAS for chonsurid from 2295 to 2164, for heparin from 530 to 346, for ronidase from 4641 to 197. The expediency of applying surface number was proved.

ВПЛИВ КОЕФІЦІЄНТА ПОВЕРХНЕВОГО НАТЯГУ РІДКОГО ТЕПЛОНОСІЯ НА СЕРЕДНЮ ТОВЩИНУ ПРИГРАНИЧНОГО ЛАМІНАРНОГО ШАРУ В РЕКУПЕРАТИВНИХ ТЕПЛООБМІННИКАХ

В процесах теплообміну визначальними є гідромеханічні характеристики потоків теплоносіїв, а саме їхні режими руху. В рекуперативних теплообмінниках загальний тепловий опір системи на 95% концентрується в пристінній області потоків теплоносіїв – в ламінарному при поверхневому шарі (ЛПШ). В існуючих рівняннях для розрахунку середніх товщин ЛПШ не враховуються поверхневі характеристики рідкофазних теплоносіїв (коефіцієнта поверхневого натягу та гідрофільності поверхні змочування). Зроблено силовий аналіз елементарного об’єму рідини в ЛПШ і встановлено пріоритетну дію сил поверхневого натягу та сил тиску. Виведена формула для розрахунку середньої товщини ЛПШ з врахуванням цих сил та коефіцієнта турбулізації КТ та співвідношення Дарсі–Вейсбаха. Одержана формула містить коефіцієнти поверхневого натягу, динамічної в’язкості та густину рідкого теплоносія, гідрофільність поверхні змочування внутрішньої рекуперативної стінки, довжину та діаметр труб, числа Рейнольдса та Дарсі, коефіцієнт турбулізації потоку.
 Запропоновано зменшувати середню товщину ЛПШ шляхом додавання до потоків теплоносіїв оптимальних концентрацій поверхнево–активних речовин (ПАР). Показано, що за додавання оптимальних концентрацій аніонактивних, неіоногенних та катіонактивних ПАР середня товщина ЛПШ зменшується в межах до 30%.

Study of High-Pressure Physical Properties of Marine Heavy Oil

This paper obtains the formula for calculating fuel dynamic viscosity based on the Barus formula and Eying formula from both macroscopic and microscopic perspectives, studies the mathematical model of fuel bulk modulus changing with temperature and pressure based on equation of state for gases and solids, and computes the fitting formula and correlation coefficients of dynamic viscosity and bulk modulus based on IFO 180 test data. The result indicates that the calculation models for fuel dynamic viscosity and bulk modulus are effective.

Viscosity of liquid Cu-In-Sn alloys

Measuring the viscosity of liquid Cu85In11Sn4, Cu80In15Sn5, Cu75In15Sn10, Cu55In7Sn38, Cu33In50Sn17, and Cu26In55Sn19 alloys has been performed using an oscillating-cup method. The temperature dependencies of the viscosity of liquid Cu-In-Sn alloys obtained show a decrease in viscosity values and an increase in temperature, in accordance with an exponential Arrhenius-type equation. The dynamic viscosity coefficient has been calculated by a number of thermodynamic models across three sections Cu85In15-In15Sn85, Cu-In75Sn25 and In-Cu60Sn40 at 1073K. A satisfactory agreement has been found between experimental and calculated data.

On the electronic viscosity of a Dirac fluid in deformed graphene

We discuss the properties of the electronic viscosity of a Dirac fluid in deformed graphene by introducing a strain and a velocity gradient , as equivalent to a pseudo-magnetic and a pseudo-electric field respectively into the Dirac equation. It is thereby analytically established that the dynamic shear viscosity coefficient substantially decreases with the applied strain as , reaching as much as for .

Transport properties of microemulsions with ionic liquid apolar domains as a function of ionic liquid content

The conductivity, dynamic viscosity and diffusion coefficient of aqueous ionic liquid microemulsions were measured as a function of ionic liquid content. ​The conclusions from transport properties were supported by UV-Vis as well as FTIR measurements.

Numerical study of spray micro-droplet impinging on dry/wet wall

The phenomenon of spray impinging on in-cylinder walls has significant impact on combustion process and harmful emissions for internal combustion engines. Spray/wall impinging process is affected by the physical properties of the droplet, the motion status of the surrounding air and the surface condition of the walls. In this paper, volume of fluid (VOF) method and liquid–solid wetting model are adopted to carry out numerical simulation of the impinging processes between spray micro-droplets and walls. Results show that, compared to millimeter diameter droplet, the incident energy of the droplet is still the key factor in the decision to spreading or splashing for the micro-droplet. The physical properties of the liquid will more strongly affect the micro-droplet spreading process after the impinging in comparison with millimeter diameter droplet. The dynamic viscosity coefficient of micro-droplets has greater impact than the surface tension. The critical parameter K to determine the droplet splash/non-splash boundary changes from K=Re0.25∗We0.5 (for millimeter diameter droplet) to K=Re0.5∗We0.33 (for spray micro-droplet). Liquid film on the wet wall will promote the spray micro-droplet easier to splash and the critical parameters K comes to K = 110, while it is 122 for dry wall.

Mathematical Models For Calculating The Value Of Dynamic Viscosity Of A Liquid

AbstractThe objective of this article is to review models for calculating the value of liquid dynamic viscosity. Issues of viscosity and rheological properties of liquid ferrous solutions are important from the perspective of modelling, along with the control of actual production processes related to the manufacturing of metals, including iron and steel. Conducted analysis within literature indicates that there are many theoretical considerations concerning the effect of viscosity of liquid metals solutions. The vast majority of models constitute a group of theoretical or semi-empirical equations, where thermodynamic parameters of solutions, or some parameters determined by experimental methods, are used for calculations of the dynamic viscosity coefficient.This article presents equations belonging to four groups of models for calculating the value of the dynamic viscosity coefficient: rheological models, non-rheological models, non-rheological and rheological models for calculating viscosity of metals. The last group of equations is developed by own experiments – high temperature rheological liquid steel measurements.

High-Temperatures Rheometric Analysis Of Selected Heterogeneous Slag Systems

Abstract It is known that the dynamic viscosity coefficient of slag – with an increased titanium compounds content in the reducing conditions of the blast furnace - may rapidly change. The products of the reduction reaction, precipitation and separation of titanium compounds are responsible for the thickening effect of the slag and the problems of permeability of blast furnace, causing anomalies in the dipping zone. The presence of solid components (particles) in the melts determines the rheological character of the entire system. Identifying the rheological character of semi-solid slag systems provides opportunities for the development of mathematical modeling of liquid phase flows in a dripping zone of the blast furnace, allowing e.g to indentify the unstable parts of a metallurgical aggregate. Author have performed study of synthetic aluminosilicates slag concentration of TiO2 in the range up to 30%, systems were doped solids TiN also, it was made in order to assess the impact of the type forming areas/units of the SRO nature on the rheological identification mentioned systems. The high-temp rheometric measurements were performed at temperatures in the range between 1310-1490°C. The obtained results made it possible to carry out the rheological characteristics of analyzed liquid and semi-solid slag systems.

Analysis of the Rheological Behaviour of Selected Semi-Solid Slag Systems in Blast Furnace Flow Conditions

Abstract The rheological properties of liquid and semi-solid systems of slag and hot metal in a blast furnace are extremely important from the perspective of their dripping in the unit. The rheological nature and the values of the dynamic viscosity coefficient of liquid and semi-solid phases - slag and hot metal - determine the permeability of the zones in which those systems exist. The modelling of dripping processes and e.g. static and dynamic holding/retention of liquid in the bed, requires an accurate description of the rheological behaviour of slag and iron systems. Determining the liquid flow through the lump bed of the blast furnace is based on the assumption that liquids in the unit in the whole range of their occurrence are similar to a Newtonian ideal liquid. This study presents an analysis of the findings of high-temperature rheometric measurements of CaO-SiO2-Al2O3-MgO systems, liquid, semi-solid slags of the blast furnace type doped with TiO2 and solids in the form of TiN. The tests were performed within a temperature range of 1310-1490°C. Also measurement results for glycerol solutions with concentrations of 86% and 100% at the ambient temperature, simulating blast furnace slags with various contents of solids - PC, anthracite - are presented.

Transport properties of aqueous ionic liquid microemulsions: influence of the anion type and presence of the cosurfactant

Transport properties, viz. specific conductivity, dynamic viscosity and apparent diffusion coefficients, were measured as a function of water content in aqueous ionic liquid microemulsions containing 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6] and bis(trifluoromethanesulphonyl)imide, [BMIM][Tf2N], stabilized by the nonionic surfactant TX-100, or its mixture with a cosurfactant, i.e. butanol. The investigation covered the whole water content range through various (Winsor I-III and dissolved solution) structures of the system. The comparative approach allowed closer inspection into phenomena being on the background of observed transport properties behavior taking into account the influence of the cosurfactant. The addition of butanol offers considerable advantages, such as an increase in conductivity, especially in systems containing ionic liquids with lower conductivity. This is accompanied by a significant decrease in viscosity, even to values that are comparable with those of molecular solvents. Moreover, the reasons for the surprisingly higher conductivity of [BMIM][PF6]-based systems were provided, and the conclusions were supported by cyclic voltammetry as well as spectrophotometric and dynamic light scattering measurements.

Simulation studies on the transport properties of Cu-H2O nanofluids based on water continuum assumption

Nanofluid is a kind of new engineering medium which is created by dispersing small quantity of nano-sized particles in the base fluid. The dispersion of solid nanoparticles in conventional fluids changes their transport properties remarkably. Molecular dynamics simulation (MDS) is an important approach to study the transport properties of nanofluids. However, the computation amount is huge, and it is very difficult to use the normal MDS to capture the transient flow and heat processes in Cu-H2O nanofluids if the regions in the simulation reach 149.6443 nm3 or 299.2883 nm3, and the number of Cu nano-particles reaches 6-64. Further study by means of simulation on the effects on effective transport properties of nanofluids is also difficult. In this paper, the water-based fluid region of 149.6443 nm3 or 299.2883 nm3 is assumed as continuum phase because of the very low Knudsen number of fluid, and the effects of water on nano-particles are fitted into the Cu-Cu potential parameters. Using the proposed method, the computation amount is significantly reduced. The effective thermal conductivity and dynamic viscosity coefficient of Cu-H2O nanofluids under the stationary condition are simulated and the results are verified with existing experimental data. The motion and aggregation processes of nano-particles in the water-based fluids at different velocity shear rate are simulated. Effects of velocity shear rate, fluid velocity, temperature gradient, and average temperature on the effective thermal conductivity and the dynamic viscosity of Cu-H2O nanofluids in the processes of flow and heat transfer are studied. Three conclusions can be drawn from the obtained results. Firstly, the proposed method is feasible to capture the transient flow and heat processes in Cu-H2O nanofluids, and is also capable to further study the transport properties of Cu-H2O nanofluids. Secondly, the velocity shear rate acting on a nanofluid can effectively prevent the aggregating process of nano-particles, and therefore reduce the diameter of particle-aggregations. Finally, the velocity shear rate and the average temperature of Cu-H2O nanofluids have much more effects on the transport properties, while the fluid velocity and temperature gradient have less effects; the velocity shear rate increases the effective thermal conductivity of a nanofluid but decreases its dynamic viscosity. A rise of average temperature increases the effective thermal conductivity but decreases the dynamic viscosity.

Determination of Flow Curves on Selected Steel Grades in Their Liquid State/ Wyznaczanie Krzywych Płynięcia Wybranych Gatunków Stali W Stanie Ciekłym

Abstract Issues of viscosity and rheological properties of liquid ferrous solutions are important from the perspective of modelling, along with the control of actual production processes related to the manufacturing of metals, including iron and steel. Conducted analysis within subject literature indicates that there are many theoretical considerations concerning the effects of viscosity of liquid metal solutions. The objective of this study was to perform rheological measurements of liquid ferrous solutions, the results of which may be used as the basis for developing viscosity models as a function of chemical composition, temperature, and a selected rheological parameter. The study contains the results of rheological tests of ferrous solutions - six chemical compositions with a carbon content from 0.15 to 0.39% and which were tested with applied shear rates from 40 to 180 s-1. The obtained values of dynamic viscosity coefficient are within the range of 0.002 - 0.018 Pa s.

C-2005: Effect of extracellular concentration profile on the precision of the experimentally determined cell membrane permeabilities through osmotic shift tests using a microperfusion chamber

The transportation of water and cryoprotective agents across the cell membrane plays an important role in cell survival during freezing and thawing of cells. A microperfusion chamber was developed for studying cellular response to osmotic change. The cells are immobilized in the microperfusion chamber and exposed to the solution which is osmotic solution shift to hypertonic solution. The change of extracellular concentration has a certain impact on fitting cell membrane permeability parameters. The microperfusion chamber can be modeled through the mechanism of convection diffusion, and thus the Finite Element Analysis (FEA) was applied for the simulation of extracellular concentration. The validity of the concentration shift model was confirmed by comparing the cell-free experimental results used by the optical image processing with the results of simulation model. The CuCl 2 solution was used to do the cell-free experiment and NaCl solution was used to do the determined cell membrane permeabilities experiment, thus the dynamic viscosity and diffusion coefficient of the solution at the certain concentration difference were measured to ensure the accuracy of the stimulant results. The simulation results have shown that the T-pipe and Y-pipe make no difference on the concentration change, but the size of T-pipe has a significant impact on extracellular NaCl concentration. The equilibration time of the low concentration shift to high concentration is about 100s, and the simulation shows the equilibration time of concentration function affects the measurement of hydraulic conductivity. Thus using FEA to analysis the extracellular concentration profile of microperfusion chamber has a great prospect to service for the cryobiology research by improving the precision of the experimentally determined cell membrane permeabilities.

Calculation of the Optimum Fractional Composition of Initial Disperse Filler

A method was developed for calculating the optimum fractional composition of the initial disperse filler of a polymer composite material based on three-dimensionally crosslinked (cured) elastomer. As the optimisation criteria, an examination was made of the coefficient of dynamic viscosity of the polymer suspension and the initial viscoelasticity modulus of cured low-molecular-weight rubbers with terminal functional groups, filled with polyfractional silicon dioxide. The influence of the packing density of the filler particles on the energy of mechanical failure was investigated. A composite material is proposed for use as a cold-resistant waterproofing coating for asphalt road surfaces, making it possible to increase their service life by many factors.

HIGH TEMPERATURE RHEOMETRY OF MOLTEN AND SEMI-SOLID IONIC SOLUTIONS BEARING ALUMINIUM AND TITANIUM OXIDES

Rheological tests of molten and semi-solid ionic solutions are difficult and demanding from the point of view of instrumentation and testing methodology. Reports that do exist in references often contain measured values of dynamic viscosity coefficient of analysed slag systems. However, these are based on the assumption that the analysed systems are liquids similar to what would be regarded as the Newtonian perfect body, and few papers contain analyses of viscosity problems from the standpoint of rheological characteristics of the systems examined. So the authors of this article have undertaken the subject of rheological characteristics of liquid ionic solutions of the blast furnace type. A prototype, high-temperature, rotary, multi-point viscometer with a rotating internal cylinder has been used for these tests. The article presents selected results of tests and rheological analyses of completely molten and semi-solid slag systems with additions of TiO 2 and Al 2 O 3 within a temperature range of 1310-1490 o C.