Deborah’s number

The origin of Deborah s number is indicated in the frontispiece to this text. In Figure 4.1.2 we take the characteristic flow time to be the inverse of the typical deformation rate while in oscillatory flows we use the amplitude of the oscillatory strain times its frequency (yaO)). Die elastic, Newtonian, and linear viscoelastic limits illustrated in Figure 4.1.2 have already been discussed in Ch ters 1, 2, and 3, respectively. Second-order fluids, to be covered shortly, reside in a fringe of the regime of nonlinear viscoelasticity that lies just across the border from the Newtonian domain. 

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