Viscosity kinetic

As shown in Fig. 6 [19], for the lubricant with higher viscosity (kinetic viscosity from 320 mm /s to 1,530 mm /s), the film is thick enough so that a clear EHL phenomenon can be observed, i.e., the relationship between the film thickness and speed is in liner style in the logarithmic coordinates. 

However, for the lubricants with lower viscosity, e.g.. Polyglycol oil 1 and 2 with the kinetic viscosity of 47 mm /s to 145 mm /s in Table 1, the transition from EHL to TFL can be seen at the speed of 8 mm/sand23 mm/s, i.e., the relationship between film thickness and speed becomes much weaker than that in EHL. The transition regime can be explained when the film reduces to several times the thickness of the molecular size, the effect of solid surface forces on the action of molecules becomes so strong that the lubricant molecules become more ordered or solid like. The thickness of such a film is related to the lubricant viscosity or molecular size. 

The unit of Pf here is MPa is the kinetic viscosity of lubricant in mm /s u is the velocity in mm/s, for the oil without polar additives, k is 23.5 X 10". If the tribo-pairs need to be lubricated with the fluid film in the TFL and EHL regime, the lubricant and the rolling speed should be chosen according to the pressure applied as Eq (9) so as to make that the liquid factor L is larger than the failure fluid factor L. Otherwise, the liquid film caimot be maintained under the pressure added. 

Conversion between Kinetic Viscosity and Absolute Viscosity for Air... 

Pipe Diameter (inches) x Kinetic Viscosity (centistokes)... 

Co304 pellets used in practice are of 4-5 mm in size. Thus, they are much larger than the diameter of wires in platinum gauzes. For this reason, in contrast to the reaction on gauzes, the reaction on Co304 pellets under atmospheric pressure is characterized by the Reynolds number much larger than 1, the Reynolds number being defined by Re = ul/v where u is the linear velocity of the stream, / is the characteristic dimension, v is the kinetic viscosity coefficient. The thickness of the diffusion layer for such pellets is... 

Figure 4.6 Relationship between average wave number of smallest eddy group and kinetic viscosity.

As the vessel size increases beyond 1 liter or the kinetic viscosity rj/p becomes very small (that is, <0.1 cm /sec), turbulence sets in, the heat transfer improves, and the gradients are diminished (see Benson, loc. cit). 

Viscosity. It shall be detd in accordance with method 305.6 of Federal Test Method Std 791B (Jan 1969) (ASTM Method D445-65). The time is measured for a fixed vol of the liq to flow thru a calibtated Ubbelohde capillary viscometer under an accurately reproducible head and at a closely controlled temp. The kinetic viscosity is then calculated from the measured time flow and the calibration constant of the viscometer. Kinetic viscosity is a measure of the time for a fixed vol of liq to flow by gravity thru a capillary. It is usually expressed in centistokes, cSt, so that 1 St = 100 cSt. The dynamic viscosity is the product of kinematic viscosity density of the liq, both at same temp. The unit is poise, P, in g/cm/sec [For details see ASTM Standard, Part 17(1971), ppl78—83]... 

For a drop, the solution naturally depends on the ratio between the kinetic viscosities of the outer and inner fluids [146, 172, 21, 174]. A closed form of K t — t) has not been obtained for this case [96]. 

The Schmidt number, Sc = v/D, that determine the ratio between the kinetic viscosity or the diffusivity of momentum and the molecular diffusivity of mass. 

Example 11-5. How w ould your answers change if the reaction were carried out in the liquid phase where kinetic viscosity saried as. 40UOJf j 0... 

For many years, the term Bunker C fuel oil has been widely used to designate the most viscous residual fuels for general land and marine use. Recognizing the need for a wide and more accurate classification for residual fuels, particularly when used for marine applications, in 1977 the major oil companies in cooperation with other interested parties introduced an expanded list of grading for residual oils. The intermediate fuel oil (IFO) grades are based upon the kinetic viscosity in centistokes (cSt) at 50°C. 

The flux is the Stokes settling velocity of a spherical particle times the number of particles in that size interval. In the expression, g is the gravitational acceleration, v the kinetic viscosity, and pp and pt the particle and fluid densities. The time unit is indicated by [t]. 

In the formula, jx, p respectively are kinetic viscosity of gas and atmospheric pressure. 

Poise (P for Poiseuille). Kinetic viscosity represents the quotient of dynamic viscosity and fluid density (unit Stokes, (St)). 

EXCESS KINETIC VISCOSITY OF BINARY MIXTURES. IGUCHIA... 

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