The plastic yield strength is evaluated using microhardness test data (see Discussion below for details). 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 number, the Deborah number De (or Weissenberg number) and is defined as the ratio of material to process time. Deborah number, abbreviated as De, a dimensionless number, is the ratio of fluidity of materials under specific flow conditions, primarly used in rheology. The sum of these numbers is 3 â 7 + 5 + 13 â 2 = 12 ; The ratio of both, the De (Deborah) number is an important process parameter. 2. 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 â R d (d = 2, â¦ The term âDeborah numberâ was first coined by Reiner (1964) and was inspired by the statement âThe mountains flowed before the lordâ of Deborah in the Bible (Judges 5:5), since De measures the ability of a material to âflowâ, that is, to deform by viscous creep. 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). 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. garnet (Karato et al., 1995; Wang and Ji, 1999), as given in the next section. For example 3 + (â2) = 3â2 = 1. We = Weber number (dimensionless) Ï = density of fluid (kg/m 3, lb/ft 3) Adding a negative number is the same as subtracting the number (without the negative). Measurements in Knowing this, let us try an example: Example 3: Find the mean of these numbers: 3, â7, 5, 13, â2. 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. Deborah Number formula $$\large{ De = \frac{ t_c }{ t_p } }$$ 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. We = Ï v 2 l / Ï (1) where. 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. It can be expressed as. We study the small Deborah number limit of the DoiâOnsager equation in the case when hydrodynamic effects are neglected. The thickness of the plastic yield region is plotted as contours. The nondimensionalization of the governing equations of fluid flow is important for both theoretical and computational reasons. The Deborah number can be evaluated using the experimental flow law of a single crystal, e.g. 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 Deborah number also represents the relationship between the heat transferred by conduction and the accumulation of heat in the material.