Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Shear Recovery after steady Shearing Flow

Shear Recovery after Steady Shearing Flow (362) [Pg.155]

The total amount of shear recoil after steady state shear flow at sufficiently low shear rates is related to Je°  [Pg.155]

When the shear rate at steady state is in the non-Newtonian region for the fluid, the recoil is smaller than J°a0 for both broad and narrow molecular weight distributions (362). [Pg.155]


FIG. 15.11 Total, viscous and recoverable (i.e. elastic) deformations, y, yvis and yrec, respectively, during steady shear flow and recovery after cessation of flow at time f,. [Pg.553]

After this rather extensive discussion of the experimental verification of eqs. (2.11), (2.20) and (2.22), where the interrelations of steady flow properties with dynamic properties and shear recovery are scrutinized, a few words should be added with respect to stress-relaxation after cessation of steady shear flow. As pointed out above, Lodge predicted a decrease of the extinction angle during stress relaxation (4). That this... [Pg.200]

There are other more complicated experimental situations where viscoelastic behavior can also be predicted in terms of the relaxation and retardation spectra or other functions. These include deformations at constant rate of strain and constant rate of stress increase, stress relaxation after cessation of steady-state flow, and creep recovery or elastic recoil, all of which were mentioned in Chapter 1, as well as nonsinusoidal periodic deformations. In referring to stress a, strain y, and rate of strain 7, the subscript 21 will be omitted here although it is understood that the discussion applies to shear unless otherwise specified. [Pg.71]

An alternative to the preceding experiment is, after steady shear flow of a viscoelastic liquid under stress creep recovery is simply given by the creep function. The strain at 2 is 7(t2) = + tV Jo) the strain during the re-... [Pg.73]

The concept of the Graessley theory that the steady-state concentration of entanglements is diminished during flow at high shear rates implies that the steady-state compliance Ry observed in recovery after cessation of steady-state flow will be larger than J and given by the equation ... [Pg.259]

The steady-state shear compliance as determined by recovery after cessation of steady-state non-Newtonian flow may be defined by analogy with equations 40... [Pg.519]


See other pages where Shear Recovery after steady Shearing Flow is mentioned: [Pg.2669]    [Pg.50]    [Pg.50]    [Pg.83]    [Pg.793]    [Pg.58]    [Pg.9111]    [Pg.55]    [Pg.520]    [Pg.1404]    [Pg.3144]    [Pg.8]    [Pg.404]   


SEARCH



Shear steady

Shearing flow

Steady shear flow

© 2024 chempedia.info