**dynamic viscosity**- The dimensions of dynamic viscosity are force times time divided by area. (britannica.com)
- For some applications the kinematic viscosity is more useful than the absolute, or dynamic, viscosity. (britannica.com)
- The dynamic viscosity of a fluid expresses its resistance to shearing flows, where adjacent layers move parallel to each other with different speeds. (wikipedia.org)
- Shear and dynamic viscosity are much more known than two others. (newworldencyclopedia.org)
- The kinematic viscosity (also called "momentum diffusivity") is the ratio of the dynamic viscosity μ to the density of the fluid ρ. (wikipedia.org)
- This page is a progressive and labeled list of the SI dynamic viscosity orders of magnitude, with examples appended where possible. (wikipedia.org)

**displaystyle**- In many non-Newtonian fluids, the shear stress due to viscosity, τ x y {\displaystyle \tau _{xy}} , can be modeled by τ x y = k ( d u d y ) n {\displaystyle \tau _{xy}=k\left({\frac {du}{dy}}\right)^{n}} where k is the consistency index n is the flow behavior index du/dy is the shear rate, with velocity u and position y These fluids are called power-law fluids. (wikipedia.org)
- Intrinsic viscosity [ η ] {\displaystyle \left[\eta \right]} is a measure of a solute's contribution to the viscosity η {\displaystyle \eta } of a solution. (wikipedia.org)
- Intrinsic viscosity is defined as [ η ] = lim ϕ → 0 η − η 0 η 0 ϕ {\displaystyle \left[\eta \right]=\lim _{\phi \rightarrow 0}{\frac {\eta -\eta _{0}}{\eta _{0}\phi }}} where η 0 {\displaystyle \eta _{0}} is the viscosity in the absence of the solute and ϕ {\displaystyle \phi } is the volume fraction of the solute in the solution. (wikipedia.org)
- As defined here, the intrinsic viscosity [ η ] {\displaystyle \left[\eta \right]} is a dimensionless number. (wikipedia.org)
- When the solute particles are rigid spheres at infinite dilution, the intrinsic viscosity equals 5 2 {\displaystyle {\frac {5}{2}}} , as shown first by Albert Einstein. (wikipedia.org)
- In practical settings, ϕ {\displaystyle \phi } is usually solute mass concentration (c, g/dL), and the units of intrinsic viscosity [ η ] {\displaystyle \left[\eta \right]} are deciliters per gram (dL/g), otherwise known as inverse concentration. (wikipedia.org)
- Reduced viscosity is equal to the ratio of the relative viscosity increment ( η i {\displaystyle \eta _{i}} ) to the mass concentration of the polymer. (wikipedia.org)
- Common symbols for volume viscosity are ζ {\displaystyle \zeta } and μ v {\displaystyle \mu _{v}} . Volume viscosity appears in the classic Navier-Stokes equation if it is written for compressible fluid, as described in the most books on general hydrodynamics and acoustics. (wikipedia.org)
- The parameters μ {\displaystyle \mu } and ζ {\displaystyle \zeta } was originally called the first and second viscosity coefficients, respectively. (wikipedia.org)
- He continues with an example and says at the end Hence, if the relaxation time of these processes is long, a considerable dissipation of energy occurs when the fluid is compressed or expanded, and, since this dissipation must be determined by the second viscosity, we reach the conclusion that ζ {\displaystyle \zeta } is large. (wikipedia.org)

**Older Viscosity**- Older Viscosity bottle purchased at Binny's in Chicago in 2015. (beeradvocate.com)
- it was a good night), I remember being impressed with Older Viscosity. (beeradvocate.com)
- I recently purchased an Older Viscosity and look forward to doing a side by side. (beeradvocate.com)

**volume viscosity**- These forces are related to the rate of compression or expansion by a factor called the volume viscosity, bulk viscosity or second viscosity. (wikipedia.org)
- Volume viscosity (also called second coefficient of viscosity or dilatational viscosity or bulk viscosity) becomes important only for such effects where fluid compressibility is essential. (wikipedia.org)
- Volume viscosity is mainly related to the vibrational energy of the molecules. (wikipedia.org)
- The volume viscosity is important in describing sound attenuation in molecular gases, and the absorption of sound energy into the fluid depends on the sound frequency i.e. the rate of fluid compression and expansion. (wikipedia.org)
- Volume viscosity is also important in describing the fluid dynamics of liquids containing gas bubbles. (wikipedia.org)
- For an incompressible liquid the volume viscosity is superfluous, and does not appear in the equation of motion. (wikipedia.org)
- This coefficient of proportionality is called volume viscosity. (wikipedia.org)
- Neither shear nor volume viscosity are equilibrium parameters or properties, but transport properties. (wikipedia.org)

**absolute viscosity**- This constant is called the dynamic , or absolute, viscosity and often simply the viscosity. (britannica.com)
- Kinematic viscosity is the absolute viscosity of a fluid divided by its mass density . (britannica.com)

**apparent viscosity**- For a Newtonian fluid, the apparent viscosity is constant, and equal to the Newtonian viscosity of the fluid, but for non-Newtonian fluids, the apparent viscosity depends on the shear rate. (wikipedia.org)
- Apparent viscosity has the SI derived unit Pa·s (Pascal-second, but the centipoise is frequently used in practice: (1 mPa·s = 1 cP). (wikipedia.org)
- A single viscosity measurement at a constant speed in a typical viscometer is a measurement of the apparent viscosity of a fluid. (wikipedia.org)
- In the case of non-Newtonian fluids, measurement of apparent viscosity without knowledge of the shear rate is of limited value: the measurement cannot be compared to other measurements if the speed and geometry of the two instruments is not identical. (wikipedia.org)
- An apparent viscosity that is reported without the shear rate or information about the instrument and settings (e.g. speed and spindle type for a rotational viscometer) is meaningless. (wikipedia.org)
- Multiple measurements of apparent viscosity at different, well-defined shear rates, can give useful information about the non-Newtonian behaviour of a fluid, and allow it to be modeled. (wikipedia.org)
- n-1}} gives the apparent viscosity. (wikipedia.org)
- Time-dependent viscosity is a property of one class of non-Newtonian fluids in which the apparent viscosity of the fluid changes with time as the fluid continues to undergo shear. (wikipedia.org)
- In the case of time dependent viscosity, the apparent viscosity of a fluid changes with time as the fluid is continuously sheared. (wikipedia.org)
- If the apparent viscosity decreases with time, the fluid is called thixotropic and if it increases with time, it is called rheopectic. (wikipedia.org)

**kinematic viscosity**- The unit of kinematic viscosity in the centimetre-gram-second (CGS) system, called the stokes in Britain and the stoke in the U.S., is named for the British physicist Sir George Gabriel Stokes . (britannica.com)
- Under ideal conditions, this rate of flow would be proportional to the kinematic viscosity (expressed in stokes and centistokes) that is dependent upon the specific gravity of the draining liquid. (wikipedia.org)

**Newtonian**- Fluids that behave in this way are called Newtonian fluids in honour of Sir Isaac Newton , who first formulated this mathematical description of viscosity. (britannica.com)
- Non-Newtonian fluids are those that behave differently than Newtonian fluids do with regard to viscosity. (reference.com)
- For a Newtonian Fluid, the uniaxial elongational viscosity is three times the shear viscosity which can be derived using the continuity equation for incompressible fluids. (wikipedia.org)
- 1955) "Non-Newtonian Viscosity of Solutions of Ellipsoidal Particles", J. Chem. (wikipedia.org)
- For a Newtonian fluid the shear viscosity is a pure fluid property, but for a non-Newtonian fluid it is not a pure fluid property due to its dependence on the velocity gradient. (wikipedia.org)
- Most commonly, in a non-Newtonian fluid, the viscosity (the measure of a fluid's ability to resist gradual deformation by shear or tensile stresses) of the fluids is dependent on shear rate or shear rate history (time). (wikipedia.org)

**fluid**- Viscosity , resistance of a fluid (liquid or gas) to a change in shape, or movement of neighbouring portions relative to one another. (britannica.com)
- The viscosity of a fluid (pure or not) is a measure of its ability to resist deformation. (britannica.com)
- The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress . (wikipedia.org)
- Viscosity is a property of the fluid which opposes the relative motion between the two surfaces of the fluid that are moving at different velocities . (wikipedia.org)
- In simple terms, viscosity means friction between the molecules of fluid. (wikipedia.org)
- [ not verified in body ] A fluid with a relatively high viscosity, such as pitch , may appear to be a solid . (wikipedia.org)
- The internal friction of a fluid in motion and it's unofficial "thickness" can also be described in terms of the viscosity of a particular fluid. (reference.com)
- First, the numbers are ratings of viscosity -- the rate of flow of a fluid -- based on SAE (Society of Automotive Engineers) specified testing. (kbb.com)
- Viscosity is a measure of the resistance of a fluid to deform under either shear stress or extensional stress. (newworldencyclopedia.org)
- Viscosity describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction . (newworldencyclopedia.org)
- There are several different viscosity coeffients depending on the nature of applied stress and nature of the fluid. (newworldencyclopedia.org)
- Viscosity is usually described as the property of a fluid which determines the rate at which local momentum differences are equilibrated. (wikipedia.org)
- the longer the fluid undergoes shear stress, the lower its viscosity. (wikipedia.org)
- A thixotropic fluid is a fluid which takes a finite time to attain equilibrium viscosity when introduced to a step change in shear rate. (wikipedia.org)
- the longer the fluid undergoes shearing force, the higher its viscosity. (wikipedia.org)

**relatively high viscosity**- The first ink would be fairly dense-of a relatively high viscosity. (wikipedia.org)

**ratio**- Relative viscosity is the ratio of the polymer viscosity to the solvent viscosity. (cheresources.com)
- The condition of the lubricant is described by the viscosity ratio κ as the ratio of the actual viscosity ν to the rated viscosity ν 1 for adequate lubrication, both values being considered when the lubricant is at normal operating temperature, see the section Selection of lubricating oil. (skf.com)
- Inherent viscosity is the ratio of the natural logarithm of the relative viscosity to the mass concentration of the polymer. (wikipedia.org)
- The intrinsic viscosity is very sensitive to the axial ratio of spheroids, especially of prolate spheroids. (wikipedia.org)

**coefficient of viscos**- When looking at a value for viscosity, the number that one most often sees is the coefficient of viscosity. (newworldencyclopedia.org)

**gases**- the viscosity of gases increases with an increase in temperature. (britannica.com)
- Gases also have a viscosity, but this property is harder to observe during ordinary circumstances. (reference.com)

**polymer**- Synthetic oils have the advantage of natural 'viscosity index improvers' (VIIs) so don't require many (if any) polymer VMs to achieve sufficient temperature range. (kbb.com)
- Similar to putting a thermometer into a turkey to see if its been cooked long enough, viscosity can reveal how well a polymer is developed. (cheresources.com)
- Imagine someone handing you a solid cube of polymer and asking you to determine its viscosity. (cheresources.com)
- Since polymer viscosities can range from 10 -2 to 10 12 poise, one testing method really doesn't cover them all. (cheresources.com)
- Testing by solution viscosity starts with dissolving a polymer in a solvent (usually accompanied by gentle heat). (cheresources.com)
- Of greater interest to the polymer industry is a property known as intrinsic viscosity (IV). (cheresources.com)
- In polymer chemistry intrinsic viscosity is related to molar mass through the Mark-Houwink equation. (wikipedia.org)

**lower viscosity**- The first number, followed by a 'W' for 'winter,' is a measure of an oil's viscosity at sub-zero temperatures, and lower viscosity gives better flow when cold. (kbb.com)
- Thus, water is "thin," having a lower viscosity, while vegetable oil is "thick" having a higher viscosity. (newworldencyclopedia.org)

**oil's viscosity**- The second number reflects the oil's viscosity at high temperatures, based on tests at 100C (212F) -- considered 'normal' operating temperature -- and 150C (302F). (kbb.com)
- Fuel oil's viscosity strongly depends on the temperature, the higher is the temperature the lower is the viscosity. (wikipedia.org)

**actual viscosity**- From diagram 4 , assuming that the operating temperature of the bearing is 70ºC, it is found that a lubricant to an ISO VG 32 viscosity class, with an actual viscosity ν of at least 32 mm 2 /s at the reference temperature of 40ºC will be required. (skf.com)
- Viscometer measures the actual viscosity of the fuel, this value is compared with the set point in the controller and the command is sent to the heater to adjust the temperature of the fuel. (wikipedia.org)

**inherent viscosity**- The unit of inherent viscosity is dL/g. (wikipedia.org)

**different viscosity**- Three to four colors of ink are mixed, each of a different viscosity. (wikipedia.org)

**fluids**- Viscosity is a major factor in determining the forces that must be overcome when fluids are used in lubrication and transported in pipelines. (britannica.com)
- Otherwise, all fluids have positive viscosity and are technically said to be viscous or viscid. (wikipedia.org)
- Viscosity is a term used to describe the measure of a fluids resistance to flow. (reference.com)
- High viscosity fluids are able to resist motion because they have a molecular makeup that provides them with a high degree of internal friction. (reference.com)
- Low viscosity fluids will flow more easily because they are unable to resist deformation caused by shear stress or tensile stress. (reference.com)
- These shear-thickening fluids are divided into two groups: time dependent and time-independent viscosity. (wikipedia.org)

**fluid's**- For a given velocity pattern, the stress required is proportional to the fluid's viscosity. (wikipedia.org)
- The force required for this action is a measure of the fluid's viscosity. (wikipedia.org)
- In general, in any flow, layers move at different velocities and the fluid's viscosity arises from the shear stress between the layers that ultimately opposes any applied force. (newworldencyclopedia.org)

**intrinsic**- The intrinsic viscosity formula may also be generalized to include a frequency dependence. (wikipedia.org)
- For example, the intrinsic viscosity can provide rough estimates of the number of subunits in a protein fiber composed of a helical array of proteins such as tubulin. (wikipedia.org)
- More generally, intrinsic viscosity can be used to assay quaternary structure. (wikipedia.org)
- A practical method for the determination of intrinsic viscosity is with a Ubbelohde viscometer. (wikipedia.org)

**decreases**- The viscosity of liquids decreases as temperature increases. (wikipedia.org)

**polymers**- Extensional viscosity is widely used for characterizing polymers. (newworldencyclopedia.org)
- Viscosity is an important characteristic for all materials, especially polymers. (cheresources.com)
- For polymers, viscosity is used as a measuring stick. (cheresources.com)
- Primarily used for higher viscosity polymers, the melt index is a common testing method. (cheresources.com)

**rotational**- The rated viscosity ν 1 , required for adequate lubrication, can be determined from diagram 1 , using the bearing mean diameter d m = (D + d)/2, mm, and the rotational speed of the bearing n, r/min. (skf.com)
- If there is a lack of equilibrium between these degrees of freedom, then the rate of equilibration will be determined by the rotational viscosity coefficient. (wikipedia.org)

**design of notations**- Viscosity, a measurement of resistance to change for the design of notations. (wikipedia.org)
- Viscosity can also refer to: A cognitive dimension for the design of notations measuring resistance to change. (wikipedia.org)

**friction**- This behaviour, called damping of the oscillations, is produced by forces such as friction and viscosity. (britannica.com)
- The viscosity of a lubricant is closely related to its ability to reduce friction. (wikipedia.org)

**equation**- This equation is called the defining equation for shear viscosity. (wikipedia.org)
- The functional relationship between viscosity and other physical properties is described by a mathematical viscosity model called a constitutive equation which is usually more complex than the defining equation for viscosity. (wikipedia.org)
- In mathematics, the viscosity solution concept was introduced in the early 1980s by Pierre-Louis Lions and Michael G. Crandall as a generalization of the classical concept of what is meant by a 'solution' to a partial differential equation (PDE). (wikipedia.org)
- It has been found that the viscosity solution is the natural solution concept to use in many applications of PDE's, including for example first order equations arising in optimal control (the Hamilton-Jacobi equation), differential games (the Isaacs equation) or front evolution problems, as well as second-order equations such as the ones arising in stochastic optimal control or stochastic differential games. (wikipedia.org)
- If a scalar equation is degenerate elliptic (defined below), one can define a type of weak solution called viscosity solution. (wikipedia.org)

**Laminar**- High viscosity mixers are mixers designed for mixing materials with laminar mixing processes because the ingredients have such high viscosities that a turbulent mixing phase cannot be obtained at all or cannot be obtained without a high amount of heat. (wikipedia.org)
- Some products that may require laminar mixing in a high viscosity mixer include putties, chewing gum, and soaps. (wikipedia.org)

**depends**- The viscosity is not a material constant, but a material property that depends on physical properties like temperature. (wikipedia.org)

**lubricant**- If an adequate lubricant film is to be formed, the lubricant must have a given minimum viscosity when the application has reached its normal operating temperature. (skf.com)
- In order to form an adequate lubricant film between the rolling contact surfaces, the lubricant must retain a minimum viscosity when the lubricant is at operating temperature. (skf.com)

**Extensional**- Extensional viscosity (also known as elongational viscosity) is a viscosity coefficient when applied stress is extensional stress. (wikipedia.org)
- Extensional viscosity can be measured using rheometers that apply extensional stress. (wikipedia.org)

**temperature**- How do oil companies formulate multi-viscosity lubricants for all-temperature protection? (kbb.com)
- When the operating temperature is known from experience or can otherwise be determined, the corresponding viscosity at the internationally standardized reference temperature of 40°C can be obtained from diagram 2 . (skf.com)
- Table lists the viscosity grades according to ISO 3448:1992 showing the range of viscosity for each class at 40°C. Certain bearing types, e.g. spherical roller bearings, tapered roller bearings, and spherical roller thrust bearings, normally have a higher operating temperature than other bearing types, e.g. deep groove ball bearings and cylindrical roller bearings, under comparable operating conditions. (skf.com)
- Since d m = 0,5 (d + D), d m = 380 mm, from diagram 3 , the minimum rated viscosity ν 1 required to give adequate lubrication at the operating temperature is approximately 11 mm 2 /s. (skf.com)
- Viscosity index (VI) is an arbitrary measure for the change of viscosity with variations in temperature. (wikipedia.org)
- The lower the VI, the greater the change of viscosity of the oil with temperature and vice versa. (wikipedia.org)
- It is used to characterize viscosity changes with relation to temperature in lubricating oil. (wikipedia.org)
- The best oils with the highest VI will remain stable and not vary much in viscosity over the temperature range. (wikipedia.org)
- Fuel viscosity control is a technique to control viscosity and temperature of fuel oil (FO) for efficient combustion in diesel engines of motor vessels and generators of oil-fired power plants. (wikipedia.org)
- It is important when using a Ford Cup and when retesting liquids that the temperature of the cup and the liquid is maintained, as ambient temperature makes a significant difference to viscosity and thus flow rate. (wikipedia.org)
- Unless otherwise stated, all viscosities are measured at room temperature and pressure. (wikipedia.org)

**superfluids**- Zero viscosity is observed only at very low temperatures in superfluids . (wikipedia.org)

**measure**- The reciprocal of the viscosity is called the fluidity , a measure of the ease of flow. (britannica.com)
- This new micro rheometer or 'treacleometer' based upon micro and nanotechnology will measure the viscosity or 'feel' of a liquid based product, such as hair shampoo or sun block. (theengineer.co.uk)

**Latin**- The word "viscosity" is derived from the Latin " viscum ", meaning mistletoe and also a viscous glue made from mistletoe berries. (wikipedia.org)
- The word "viscosity" derives from the Latin word " viscum " for mistletoe. (newworldencyclopedia.org)

**units**- Units of viscosity" (PDF). (wikipedia.org)

**measurements**- However, the conditions in a simple flow cup are seldom ideal for making true measurements of viscosity. (wikipedia.org)

**high**- That is why today's 'multi-viscosity' oils are engineered to protect an engine throughout its full range of operating temperatures, from extreme winter cold starts to long, hot, high-speed runs on the hottest summer days. (kbb.com)
- The application of the high-viscosity ink is carried out as in any intaglio process: by forcing it into the recesses of the plate and then wiping off the plate's surface with a tarlatan. (wikipedia.org)
- Inking the acrylic or plexiglass plate with one ink with a very high viscosity, and following that, rolling a very loose ink over it, produces two tones on a single plate. (wikipedia.org)
- If it is easier to add a hack than it is to add code that fits into the program's design, then the system has high viscosity. (wikipedia.org)
- The process can be used for high viscosity liquid to liquid mixing or for paste mixing combining liquid and solid ingredients. (wikipedia.org)

**flow**- Viscosity denotes opposition to flow. (britannica.com)
- The Ford viscosity cup is a simple gravity device that permits the timed flow of a known volume of liquid passing through an orifice located at the bottom. (wikipedia.org)

**higher**- for example, honey has a much higher viscosity than water . (wikipedia.org)
- The liquid on the right has higher viscosity than the liquid on the left. (wikipedia.org)

**relative**- These two values are compared to yield a relative viscosity . (cheresources.com)

**oils**- We add viscosity modifiers (VMs) to conventional oils to artificially provide that range,' Hsu explains. (kbb.com)
- With that trend toward thinner and thinner oils, you still have to be able to keep the engine protected, and only a synthetic oil is capable of optimizing these low viscosities. (kbb.com)
- The Viscosity Index of synthetic oils ranges from 80 to over 400. (wikipedia.org)

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