Viscosity absolute

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. 

Xj = mole fraction of component i Xw, = weight fraction of component i M- = molecular weight of the component i = molecular weight of the mixture = absolute viscosity of the mixture... 

While the canal viscometer provides absolute viscosities and the effect of the substrate drag can be analyzed theoretically, the shear rate is not constant and the measurement cannot be made at a single film pressure as a gradient is required. Another basic method, more advantageous in these respects, is one that goes back to Plateau... 

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)... 

The absolute viscosities of the perfluorinated inert Hquids are higher than the analogous hydrocarbons but the kinematic viscosities are lower due to the higher density of the perfluorinated compounds. The viscosity index, ie, the change in viscosity with temperature, is generally higher for the perfluorinated Hquids than for hydrocarbons. 

Fig. 3. Stribeck curve relating friction coefficient to absolute viscosity ]1, speed N in rpm, and unit loadp.

Absolute viscosities are difficult to measure with capillary viscometers, but viscosities relative to some standard fluid of known viscosity, such as water, are readily determined. The viscometer is caHbrated with the reference fluid, and viscosities of other fluids relative to the reference sample are determined from their flow times. 

In early hterature, the molecular weights of PVDC and VDC copolymers were characterized by the absolute viscosity of a 2 wt % solution in (9-dichlorobenzene at 140°C. The exact correlation between this viscosity value and molecular weight is not known. Gel-permeation chromatography is the... 

Viscosities of Gases Coordinates for Use with Fig. 2-32.. . . Nomograph for Determining a) Absolute Viscosity of a Gas as a Function of Temperature Near Ambient Pressure and (h) Relative Viscosity of a Gas Compared... 

The absolute viscosity ( l) is defined as the sheer stress at a point... 

The Iduematic viscosity (v) is defined as the ratio of the absolute viscosity to density at the same temperature and pressure. The most common unit corresponding to the poise is the stoke (1 cmVsec). The SI unit would be mVsec. 

Viscosity, dynamic Sometimes called absolute viscosity, the shear stress in a fluid divided by the velocity gradient. 

Viscosity is a property associated with a fluid s resistance to flow more precisely, tliis property accounts for tlie energy losses resulting from shear stresses tliat occur between different portions of tlie fluid, moving at dilferent velocities. The absolute viscosity (p.) has units of mass per lengUi-time die... 

Experimentally determined viscosities are generally reported either as absolute viscosity (q) or as Idnematic viscosity (u). Kinematic viscosity is simply the absolute viscosity normalized by the density of the fluid. The relationship between absolute viscosity (q), density (p), and Idnematic viscosity (u) is given by Equation 3.2-1. 

The unit of absolute viscosity is the Poise (P, g cm s or mPa s), while the unit for Idnematic viscosity is the Stoke (St, cm s Because of the large size of these viscosity units, absolute viscosities for ionic liquids are usually reported in centipoises (cP) and Idnematic viscosities reported in centistokes (cSt). 

Figure 3.2-2 Change in the absolute viscosity (cP) as a function of the [EMIMJCI mol % in an...

Figure 2-45. Absolute viscosity of air. By permission. Standards for Steam Jet Ejectors, 3rd Ed., Heat Exchange Institute, 1956 [54] also. Standards for Steam Jet Vacuum Systems, 4th Ed., 1988 [58].

X = (lambda) yield factor, (W/W )with subscript o referring to reference value p = (mu) absolute viscosity at flowing temperature, centipoise (cp)... 

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