Dynamic Absolute Kinematic ViSCOSITY

Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Search "the most efficient way to navigate the Engineering ToolBox!"

Dynamic, Absolute and Kinematic ViscosityAn introduction to dynamic, absolute and kinematic viscosity and how to convert between CentiStokes (cSt), CentiPoises (cP), Saybolt Universal Seconds (SSU), degree Engler and more

Sponsored Links

The viscosity of a fluid is an important property in the analysis of liquid behavior and fluid motion near solid boundaries.

The viscosity is the fluid resistance to shear or flow and is a measure of the adhesive/cohesive or frictional fluid property. The resistance is caused by intermolecular friction exerted when layers of fluids attempt to slide by one another.

Viscosity is a measure of a fluid's resistance to flow

The knowledge of viscosity is needed for proper design of required temperatures for storage, pumping or injection of fluids.

Molasses is highly viscous Water is medium viscous Gases have a low viscosity

There are two related measures of fluid viscosity - known as dynamic (or absolute) and kinematic viscosity.

Dynamic (absolute) ViscosityAbsolute viscosity or the coefficient of absolute viscosity is a measure of the internal resistance. Dynamic (absolute) viscosity is the tangential force per unit area required to move one horizontal plane with respect to the other at unit velocity when maintained a unit distance apart by the fluid.

The shearing stress between the layers of non turbulent fluid moving in straight parallel lines can be defined for a Newtonian fluid as:

The dynamic or absolute viscosity can be expressed like

= dc/dy (1)

where

Convert Viscosity Oil Viscosity Dynamic Viscosity Fluid Viscosity

Page 1 of 11Dynamic, Absolute and Kinematic Viscosity

11/04/2014http://www.engineeringtoolbox.com/dynamic-absolute-kinematic-viscosity-d_412.html

= shearing stress

= dynamic viscosity

Equation (1) is known as the Newtons Law of Friction.

In the SI system the dynamic viscosity units are N s/m2, Pa.s or kg/m.s where

1 Pa.s = 1 N s/m2 = 1 kg/m.s

The dynamic viscosity is also often expressed in the metric CGS (centimeter-gram-second) system as g/cm.s, dyne.s/cm2 or poise (p) where

1 poise = 1 dyne s/cm2 = 1 g/cm.s = 1/10 Pa.s = 1/10 N.s/m2

For practical use the Poise is to large and it's usual divided by 100 into the smaller unit called the centiPoise (cP)where

1 p = 100 cP 1 cP = 0.01 poise = 0.01 gram per cm second = 0.001 Pascal second = 1 milliPascal second = 0.001 N.s/m2

Water at 68.4oF (20.2oC) has an absolute viscosity of one - 1 - centiPoise.

LiquidAbsolute Viscosity at Room Temperature

(Pa.s)Air 1.983 x 10-5

Water 1 x 10-3

Olive Oil 1 x 10-1

Glycerol 1 x 100

Liquid Honey 1 x 101

Golden Syrup 1 x 102

Glass 1 x 1040

Absolute or Dynamic Viscosity of some common Liquids

Kinematic Viscosityis the ratio of absolute or dynamic viscosity to density - a quantity in which no force is involved. Kinematic viscosity can be obtained by dividing the absolute viscosity of a fluid with it's mass density

= / (2)

where

= kinematic viscosity

= absolute or dynamic viscosity

= density

In the SI-system the theoretical unit is m2/s or commonly used Stoke (St) where

1 St (Stokes) = 10-4 m2/s = 1 cm2/s

Since the Stoke is an unpractical large unit, it is usual divided by 100 to give the unit called Centistokes (cSt)where

1 St = 100 cSt 1 cSt (centiStokes) = 10-6 m2/s = 1 mm2/s

Since the specific gravity of water at 68.4oF (20.2oC) is almost one, the kinematic viscosity of water at 68.4oF is for all practical purposes 1.0 mm2/s (cSt). The kinematic viscosity of water at 68F (20C) is 1.0038 mm2/s (cSt).

Kinematic Viscosities of Some common Liquids and Fluids



Conversion from absolute to kinematic viscosity can also be expressed as:

= 6.7197 10-4 / (2a)

where

= kinematic viscosity (ft2/s)

= absolute or dynamic viscosity (cP)

= specific weight (lb/ft3)

Viscosity and Reference TemperaturesThe viscosity of a fluid is highly temperature dependent and for either dynamic or kinematic viscosity to be meaningful, the reference temperature must be quoted. In ISO 8217 the reference temperature for a residual fluid is 100oC. For a distillate fluid the reference temperature is 40oC.

For a liquid - the kinematic viscosity will decrease with higher temperature For a gas - the kinematic viscosity will increase with higher temperature

Related Mobile Apps from The Engineering ToolBox

Kinematic Viscosity Converter App

- free apps for offline use on mobile devices.

Other Commonly used Viscosity UnitsSaybolt Universal Seconds (or SUS, SSU)Saybolt Universal Seconds (or SUS) is used to measure viscosity. The efflux time is Saybolt Universal Seconds (SUS) required for 60 milliliters of a petroleum product to flow through the calibrated orifice of a Saybolt Universal viscometer, under carefully controlled temperature and as prescribed by test method ASTM D 88. This method has largely been replaced by the kinematic viscosity method. Saybolt Universal Seconds is also called the SSU number (Seconds Saybolt Universal) or SSF number (Saybolt Seconds Furol).

Kinematic viscosity versus dynamic or absolute viscosity can be expressed as

SSU = B / SG

= B centiStokes (3)

where

SSU = kinematic vicosity (SSU)

B = 4.632 for temperature 100 oF (37.8 oC)

B = 4.664 for temperature 210oF (98.9 oC)

= dynamic or absolute viscosity (cP)

SG = Specific Gravity

centiStokes = kinematic viscosity (centiStokes)

SSU at other temperatures

Degree EnglerDegree Engler is used in Great Britain as a scale to measure kinematic viscosity. Unlike the Saybolt and Redwood scales, the Engler scale is based on comparing a flow of the substance being tested to the flow of another substance - water. Viscosity in Engler degrees is the ratio of the time of a flow of 200 cubic centimetres of the fluid whose viscosity is being measured - to the time of flow of 200 cubic centimeters of water at the same temperature (usually 20oC but sometimes 50oC or 100oC) in a standardized Engler viscosity meter.

Newtonian FluidsFluids for which the shearing stress is linearly related to the rate of shearing strain are designated as Newtonian Fluids.



Newtonian materials are referred to as true liquids since their viscosity or consistency is not affected by shear such as agitation or pumping at a constant temperature. Fortunately most common fluids, both liquids and gases, are Newtonian. Water and oils are examples of Newtonian liquids.

Shear-thinning or Pseudoplastic LiquidsShear-thinning or pseudoplastic liquids are those whose viscosity decreases with increasing shear rate. Their structure is time-independent.

Thixotropic FluidsThixotropic liquids have a time-dependent structure. The viscosity of a thixotropic liquid decreases with increasing time, at a constant shear rate.

Ketchup and mayonnaise are examples of thixotropic materials. They appear thick or viscous but are possible to pump quite easily.

Dilatant FluidsShear Thickening Fluids or Dilatant Fluids increase their viscosity with agitation. Some of these liquids can become almost solid within a pump or pipe line. With agitation, cream becomes butter and Candy compounds, clay slurries and similar heavily filled liquids do the same thing.

Bingham Plastic FluidsBingham Plastic Fluids have a yield value which must be exceeded before it will start to flow like a fluid. From that point the viscosity will decrease with increase of agitation. Toothpaste, mayonnaise and tomato catsup are examples of such products.

Example - Converting between Kinematic and Absolute Viscosity for AirKinematic viscosity of air at 1 bar (105 Pa, N/m2) and 40oC is 16.97 cSt (16.97 10-6 m2/s).

The density of air estimated with the Ideal Gas Law

= p / R T

where

= density (kg/m3)

p = absolute pressure (Pa, N/m2)

R = individual gas constant (J/kg.K)

T = absolute temperature (K)

= (105 N/m2) / ((287 J/kg/K) ((273 oC) + (33 oC)))

= 1.113 (kg/m3)

Absolute viscosity can be expressed as

= (1.113 kg/m3) (16.97 10-6 m2/s)

= 1.88 10-5 (kg/m s, N.s/m2, P)

Viscosity of some Common Liquids

centiStokes(cSt)

Saybolt SecondUniversal

(SSU, SUS)Typical liquid

1 31 Water (20oC)

4.3 40Milk

SAE 20 Crankcase OilSAE 75 Gear Oil

15.7 80 No. 4 fuel oil20.6 100 Cream43.2 200 Vegetable oil



centiStokes(cSt)

Saybolt SecondUniversal

(SSU, SUS)Typical liquid

110 500 SAE 30 Crankcase OilSAE 85 Gear Oil

220 1000Tomato Juice

SAE 50 Crankcase OilSAE 90 Gear Oil

440 2000 SAE 140 Gear Oil

1100 5000 Glycerine (20oC)

SAE 250 Gear Oil2200 10,000 Honey6250 28,000 Mayonnaise

19,000 86,000 Sour cream

Kinematic viscosity can be converted from SSU to Centistokes like

Centistokes = 0.226 SSU - 195 / SSU

where

SSU < 100

Centistokes = 0.220 SSU - 135 / SSU

where

SSU > 100

Viscosity and TemperatureKinematic viscosity of liquids like water, mercury, oils SAE 10 and oil no. 3 - and gases like air, hydrogen and helium are indicated below. Note that

for liquids viscosity decreases with temperature for gases viscosity increases with temperature

Viscosity Measurements



Three types of devices are used in viscosity measurements

capillary tube viscometer Saybolt viscometer rotatiting viscometer

Sponsored Links

Related Topics

Fluid Mechanics - The study of fluids - liquids and gases. Involves various properties of the fluid, such as velocity, pressure, density and temperature, as functions of space and time.

Fluid Flow and Pressure Drop - Pipe lines - fluid flow and pressure loss - water, sewer, steel pipes, pvc pipes, copper tubes and more

Pumps - Piping systems and pumps - centrifugal pumps, displacement pumps - cavitation, viscosity, head and pressure, power consumption and more

Material Properties - Material properties - density, heat capacity, viscosity and more - for gases, fluids and solids

Related Documents

Liquids - Kinematic Viscosities - Kinematic viscosities of some common liquids - motor oil, diesel fuel, peanut oil and many more

SAE Multigrade Oil Properties - Viscosity and density of SAE Grade oil Air Properties - Temperature, density, specific heat, thermal conductivity, expansion coefficient, kinematic

viscosity and Prandtl's number for temperatures ranging -150 - 400 oC

Dynamic Viscosity of some common Liquids - Absolute or Dynamic Viscosity viscosity of some common fluids

Reynolds Number - An introduction and definition of the dimensionless Reynolds Number - with online calculators

Viscosity Converting Chart - A viscosity converting table between units like Centiposes, milliPascal, CentiStokes and SSU

Major loss in Ducts, Tubes and Pipes - Major loss - head loss or pressure loss - due to friction in ducts, pipes and tubes

Steam Viscosity - Steam absolute viscosity at pressures ranging 1 - 10000 psia Kinematic Conversion Diagram - Convert diagram between Centistokes, Saybolt and Redwood seconds Pressure Drop in Oil Pipes - Pressure drop in oil pipes - viscosity ranging 100 - 600 Saybolt Universal

Seconds

Water - Dynamic and Kinematic Viscosity - Viscosity of water at temperatures between 0 - 100oC (32 -212oF) - in Imperial and SI Units

Friction Loss Viscous Liquids - Friction loss in steel pipes - viscosities ranging 32 - 80000 SSU Air - Absolute and Kinematic Viscosity - Absolute and kinematic viscosity of air at temperatures ranging

-40 - 1000 oC (-40 - 1500 oF) at standard atmospheric pressure - Imperial and SI Units

Kinematic Viscosity Online Calculator - Convert between different kinematic viscosity units -centistokes, poise, lentor and more

Williams Hazens Equation of Pressure Drop - The Hazen-Williams equation can be used to calculate pressure drop (psi) in pipes or tubes due to friction

Friction Loss Viscous Liquids - Friction loss in schedule 40 steel pipe with viscous liquids with viscosity from water to 1500 SSU

Water - Absolute or Dynamic Viscosity - Absolute, or dynamic viscosity of water in centipoises for temperatures between 32 - 200oF

Nano Lubricant Additiveslowerfriction.com

Add few grams to lubricant oil and start saving energy and money now



Centrifugal Pumps and Viscosity - When a liquid flow through a pump, hydrodynamic losses depends on fluid viscosity

Fuel Oils - Viscosities - Fuels oils - their viscosity versus temperature Oil Viscosity Conversion Values - Convert between common oil viscosity units Heat Emission from Pipes Submerged in Oil or Fat - Heat emission from steam or water heating pipes

submerged in oil or fat - assisted (forced) and natural circulation Dynamic Viscosity of Motor Oils - SAE 10 to 50 - temperature ranging 0 - 10 deg C Absolute or Dynamic Viscosity Online Converter - Convert between dynamic or absolute viscosity units

- Poiseuille, Poise, centPoise and more Viscous Fluids - Recommended Suction Flow Velocity - Recommended suction flow velocity of viscous

fluids

International Standard Atmosphere - International standard atmosphere - ranging elevation -2000 to 30000 meters - pressure, temperature, density, viscosity, thermal conductivity and velocity of sound

Dynamic or Absolute Viscosity Converting Chart - Absolute or dynamic viscosity converting chart -units like Poiseuille - Poise - centiPoise and more

Comparing Secondary Coolants - Specific gravity, freezing points and viscosity for secondary coolants like calcium chloride, sodium chloride, ethylene glycol and propylene glycol

Industrial Lubricants - Viscosity ISO-VG Grade - ISO-VG viscosity grades for industrial lubricants Viscous Liquids - Recommended Delivery Flow Velocities - Normal flow velocities on the delivery side

of the pump in viscous systems

ISO Grade Oil Properties - Viscosity and density of ISO Grade oil Viscosity of Foods - Absolute or dynamic viscosity of some common foods Gases - Dynamic Viscosity - Absolute viscosity of some common gases Sea Water Properties - Seawater properties - specific volume, specific heat and absolute viscosity

Search the Engineering ToolBox

Search "the most efficient way to navigate the Engineering ToolBox!"

Engineering ToolBox - SketchUp Edition - Online 3D modeling!

Engineering ToolBox - SketchUp Edition - add standard and customized parametric components - like flange beams, lumbers, piping and more - to your SketchUp model - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro. Add from the Sketchup Extension Warehouse!

Translate the ToolBoxArabic - Chinese (Simplified) - Chinese (Traditional) - Dutch - French - German - Italian - Japanese - Korean -Portuguese - Russian - Spanish - - Select Your own language . .

About the ToolBoxWe appreciate any comments and tips on how to make The Engineering ToolBox a better information source. Please contact us by email

[email protected]

if You find any faults, inaccuracies, or otherwise unacceptable information.

The content in The Engineering ToolBox is copyrighted but can be used with NO WARRANTY or LIABILITY. Important information should always be double checked with alternative sources. All applicable national and local regulations and practices concerning this aspects must be strictly followed and adhered to.

Advertise in the ToolBox



If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords.

Home

Acoustics

Air Psychrometrics

Basics

Combustion

Drawing Tools

Dynamics

Economics

Electrical

Environment

Fluid Mechanics

Gas and Compressed Air

HVAC Systems

Hydraulics and Pneumatics

Insulation

Material Properties

Mathematics

Mechanics

Miscellaneous

Physiology

Piping Systems

Process Control

Pumps

Standard Organizations

Statics

Steam and Condensate

Thermodynamics

Water Systems

Unit ConverterTemperature

0.0oCoF

Convert!

Length

Gravity Flow Viscosity Chart Flow Meter Water



1.0m km in ft yards miles nautical miles

Convert!

Volume

1.0m3

liters in3

ft3

us gal Convert!

Velocity

1.0m/s km/h ft/min ft/s mph knots

Convert!

Pressure

1.0Pa (N/m2) bar mm H2O kg/cm2

psi inches H2O

Convert!

Flow

1.0m3/s m3/h US gpm cfm

Convert!

Free Industry Magazines

Chemical Engineering



Environmental Design + Construction

appliance DESIGN

Share this Page!

+6 Share this on Google+

Tweet

Sponsored Links

Share



Free Industry Magazines

Chemical Engineering

Environmental Design + Construction

appliance DESIGN

3 27



Dynamic Absolute Kinematic ViSCOSITY

Documents

Transcript of Dynamic Absolute Kinematic ViSCOSITY