The sum of these numbers is 3 − 7 + 5 + 13 − 2 = 12 ; If a rheological experiment is faster than the relaxation process, the material will appear elastic (high De number), otherwise the viscous part will dominate (low De number). The term ‘Deborah number’ was first coined by Reiner (1964) and was inspired by the statement ‘The mountains flowed before the lord’ of Deborah in the Bible (Judges 5:5), since De measures the ability of a material to ‘flow’, that is, to deform by viscous creep. For example 3 + (−2) = 3−2 = 1. The plastic yield strength is evaluated using microhardness test data (see Discussion below for details). We = ρ v 2 l / σ (1) where. Measurements in Owing to the high conductivity of the carbon fibers and the small thickness of the laminates, typical De numbers for high performance epoxy laminates are of the order of 10. Nondimensional scaling provides a method for developing dimensionless groups that can provide physical insight into the importance of various terms in the system of governing equations. Deborah number, abbreviated as De, a dimensionless number, is the ratio of fluidity of materials under specific flow conditions, primarly used in rheology. The thickness of the plastic yield region is plotted as contours. The Weber Number is the ratio between the inertial force and the surface tension force and the Weber number indicates whether the kinetic or the surface tension energy is dominant. The ratio of t f to t r is a dimensionless number of particular significance in the study of flow of non-Newtonian fluids: depending on the circumstances, this number is called the Deborah Number or the Weissenberg Number. The ratio of both, the De (Deborah) number is an important process parameter. This is a Smoluchowski-type equation that describes the dynamics of nematic liquid crystals at a molecular level, by characterizing the evolution of a number density function, depending upon both particle position x ∈ R d (d = 2, … The Deborah number also represents the relationship between the heat transferred by conduction and the accumulation of heat in the material. Deborah Number formula \(\large{ De = \frac{ t_c }{ t_p } }\) number, the Deborah number De (or Weissenberg number) and is defined as the ratio of material to process time. garnet (Karato et al., 1995; Wang and Ji, 1999), as given in the next section. Adding a negative number is the same as subtracting the number (without the negative). The effects of various parameters, namely, Deborah numbers [Formula: see text] and [Formula: see text], Prandtl parameter [Formula: see text], Brownian motion [Formula: see text], thermophoresis parameter [Formula: see text] and Lewis number [Formula: see text], on flow and heat transfer are investigated. The Deborah number can be evaluated using the experimental flow law of a single crystal, e.g. The nondimensionalization of the governing equations of fluid flow is important for both theoretical and computational reasons. We = Weber number (dimensionless) ρ = density of fluid (kg/m 3, lb/ft 3) It can be expressed as. We study the small Deborah number limit of the Doi–Onsager equation in the case when hydrodynamic effects are neglected. Knowing this, let us try an example: Example 3: Find the mean of these numbers: 3, −7, 5, 13, −2. 2. Increasing the take up speed in a film blowing process is identical to decreasing the process time: in order for the Deborah number, characteristic for the process, to be constant, the material time has to be modified, typically