Viscosity, high pressure

From stochastic molecnlar dynamics calcnlations on the same system, in the viscosity regime covered by the experiment, it appears that intra- and intennolecnlar energy flow occur on comparable time scales, which leads to the conclnsion that cyclohexane isomerization in liquid CS2 is an activated process [99]. Classical molecnlar dynamics calcnlations [104] also reprodnce the observed non-monotonic viscosity dependence of ic. Furthennore, they also yield a solvent contribntion to the free energy of activation for tlie isomerization reaction which in liquid CS, increases by abont 0.4 kJ moC when the solvent density is increased from 1.3 to 1.5 g cm T Tims the molecnlar dynamics calcnlations support the conclnsion that the high-pressure limit of this unimolecular reaction is not attained in liquid solntion at ambient pressure. It has to be remembered, though, that the analysis of the measnred isomerization rates depends critically on the estimated valne of... 

The first term is essentially the reciprocal of the Weber number and the second term is a function of the Ohnesorge number. Equation 13 may be invaHd for airblast atomizers operating at high pressures, >1 MPa (>10 atm), or with high viscosity Hquids. 

For nonpolar, nonhydrocarbon vapor mixtures at high pressures, the method of Dean and Stiel [Eq- (2-102)] discussed earlier can be used. The accuracy of the method is excellent and dependent on the pure component viscosity values used as input parameters. 

The polymer melts at 216°C and above this temperature shows better cohesion of the melt than PTFE. It may be processed by conventional thermoplastics processing methods at temperatures in the range 230-290°C. Because of the high melt viscosity high injection moulding pressures are required. 

Visi-osity High viscosity crudes may flow in the laminar flow regime which causes high pressure drops. This is especially true of emulsions of water in high-viscosity crudes where the effective velocity of the mi slur e could be as much as ten times that of the base crude (see Volume 11... 

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