Kinematic viscosity units

In addition, the U.S. Pharmacopoeia includes the explanation of kinematic viscosity [units in stoke (s) and centistoke (cs)], defined as the absolute viscosity divided by the density of the liquid at a definite temperature, p ... 

In the SI system, the theoretical unit of v is m2/s or the commonly used Stoke (St) where 1 St = 0.0001 m2/s = 100 cSt = 100 centiStoke. Similarly, 1 centiStoke = 1 cSt = 0.000001 m2/s = 0.01 Stoke = 0.01 st. The specific gravity of water at 20.2°C (68.4°F) is almost 1. The kinematic viscosity of water at 20.2°C (68.4°F) is for all practical purposes equal to 1 cSt. For a liquid, the kinematic viscosity will decrease with higher temperature. For a gas, the kinematic viscosity will increase with higher temperature. Another commonly used kinematic viscosity unit is Saybolt universal seconds (SUS), which is the efflux time required for 60 mL of petroleum product to flow through the calibrated orifice of a Saybolt universal viscometer, as described by ASTM-D88. Therefore, the relationship between dynamic viscosity and kinematic viscosity can be expressed as... 

The kinematic viscosity is defined as the ratio between the absolute viscosity and the density. It is expressed in m /s. The most commonly used unit is mm /s formerly called centistoke, cSt. 

Poise = cgs unit of absolute viscosity Centipoise = 0.01 poise Stoke = cgs unit of kinematic viscosity Centistoke = 0.01 stoke Centipoises = centistokes X density (at temperature under consideration)... 

Kinematic viscosity v is the ratio of the dynamic viscosity to the density of a fluid. The SI unit is meter squared per second [m s ]. The c.g.s. units are called stokes [cm -s l] poises = stokes X density. 

Diesel fuel kinematic viscosity is measured by ASTM D445, and is reported in units of mm /s at 40°C. Desired viscosity is a function of fuel grade and ranges from a minimum of 1.3 mm /s for 1-D to a maximum of 24 mm /s for 4-D. 

A number of arbitrary viscosity units have also been used. The most common has been the Saybolt Universal second (SUs) which is simply the time in seconds required for 60 mL of oil to empty out of the cup in a Saybolt viscometer through a carefully specified opening. Detailed conversion tables appear in ASTM D2161, approximation of kinematic viscosity V in mm /s(= cSt) can be made from the relation shown in equation 8 ... 

Reactor Internals and Unit Hardware. Requirements for mixing feed components or separating products may determine minimum pilot unit size. If reactants caimot be premixed before they are passed into the reactor, the effectiveness of the inlet distributor in mixing the reactants can markedly affect reactor performance. This is especially tme for gases, multiple phases, or Hquid streams of greatly different kinematic viscosities. 

Viscosity is equal to the slope of the flow curve, Tf = dr/dj. The quantity r/y is the viscosity Tj for a Newtonian Hquid and the apparent viscosity Tj for a non-Newtonian Hquid. The kinematic viscosity is the viscosity coefficient divided by the density, ly = tj/p. The fluidity is the reciprocal of the viscosity, (j) = 1/rj. The common units for viscosity, dyne seconds per square centimeter ((dyn-s)/cm ) or grams per centimeter second ((g/(cm-s)), called poise, which is usually expressed as centipoise (cP), have been replaced by the SI units of pascal seconds, ie, Pa-s and mPa-s, where 1 mPa-s = 1 cP. In the same manner the shear stress units of dynes per square centimeter, dyn/cmhave been replaced by Pascals, where 10 dyn/cm = 1 Pa, and newtons per square meter, where 1 N/m = 1 Pa. Shear rate is AH/AX, or length /time/length, so that values are given as per second (s ) in both systems. The SI units for kinematic viscosity are square centimeters per second, cm /s, ie, Stokes (St), and square millimeters per second, mm /s, ie, centistokes (cSt). Information is available for the official Society of Rheology nomenclature and units for a wide range of rheological parameters (11). 

Viscosity. Although traditionally of Httle importance in the evaluation of vegetable and insect waxes, viscosity is an important test for mineral and synthetic waxes. One of the most frequently used tests, ASTM D88, is used to measure the time in seconds required for a specified quantity of wax at a specified temperature to flow by gravity through an orifice of specified dimensions. This viscosity is expressed in Saybolt Universal Seconds (SUS) at the temperature of the test. The SI unit for kinematic viscosity is mm /s (=cSt). 

Fig. 24. Generalized method using log scales for estimating packed column flooding and pressure drop, AP, in kPa/m g = gravitational constant, 9.81 m/s t = kinematic viscosity in mm /s (= cSt) E, G have units of kg/(m s) are in kg/m and the packing factor, F, in can be found in...

Note that the kinematic viscosity of a fluid is defined as the ratio of its viscosity to the fluid density. The c.g.s. unit of kinematic viscosity is usually called the stoke, and is equal to 1 cmVsec. 

Where ij. is defined as the kinematic viscosity (centistokes), and is a constant with a value of 2,213.8 in USCS units and 353.68 in SI units. An empirical relation for the Fanning friction factor is the Colebrook-White equation ... 

Another viscosity unit is the kinematic viscosity u. This is the ratio of viscosity to density. Common units used for this are the stoke (1 cm- s" ) and the centistoke (1 mm s ). 

The kinematic viscosity of a gas is a function of the pressure, and its dimension is the square of length divided by the time, its unit being m s k... 

To convert other units into kinematic viscosity in English units v (sq ft per sec) or in Metric units u (centistokes), use the chart or the formulas to the right ... 

The concept of kinematic viscosity is the outgrowth of the use of a head of liquid to produce a flow through a capillary tube. The coefficient of absolute viscosity, when divided by the density of the liquid is called the kinematic viscosity. In the metric system, the unit of viscosity is called the stoke and it has the units of centimeters squared per second. One one-hundredth of a stoke is a centistoke. 

Viscosity is a measurement of resistance to flow. Although the unit of absolute viscosity is poise, its measurement is difficult. Instead, kinematic (flowing) viscosity is determined by measuring the time for a given flow through a capillary tube of specific diameter and length. The unit of kinematic viscosity is the stoke. However, in general practice, centistoke is used. Poise is related to stoke by the equation ... 

The modified Reynolds number therefore is based on the velocity in the void fraction v/s, the kinematic viscosity v, and an equivalent diameter s/a, where s is total area per unit volume and a is the dimensional coefficient derived from a correlation of pressure drop data ... 

The unit of viscosity is the poise (gem-1 s-1). Kinematic viscosity v is often used and is defined as... 

Viscosity, as it was defined in Equation (15.1), is often called the dynamic viscosity. The most common unit of dynamic viscosity is the centipoise, a unit based on force per rate. The base unit, the poise (100 centipoise per poise) is seldom used. Of more practical significance is kinematic viscosity, which is the dynamic viscosity divided by the density of the fluid ... 

The most common unit of kinematic viscosity is the centistokes (cS), the centipoise per density unit. Again, the base unit, the stokes (S) (100 cS/S), is seldom used. 

Viscosity is the force in dynes required to move a plane 1 cm in area at a distance of 1 cm from another plane 1 cm in area through a distance of 1 cm in 1 s. In the centimeter-gram-second (cgs) system, the unit of viscosity is the poise (P) or centipoise (1 cP = 0.01 P). Two other terms in common use are kinematic viscosity and fluidity. The kinematic viscosity is the viscosity in centipoise divided by the specific gravity, and the unit is the stoke (cm /s), although the centistoke (0.01 st = 1 cSt) is in more common use fluidity is simply the reciprocal of viscosity. 

The ratio (symbolized by v) of the dynamic viscosity, or simply viscosity 17, to the fluid density, p. Kinematic viscosity has SI units of meters squared per second. 

Momentum can be transported in an analogous manner to mass or heat. The diffusion of momentum is described with a kinematic viscosity, v, which has SI units of m /s ... 

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