翻訳と辞書 Words near each other ・ Viscount Guillamore ・ Viscount Hailsham ・ Viscount Hall ・ Viscount Hambleden ・ Viscount Hampden ・ Viscount Hanworth ・ Viscount Harberton ・ Viscount Harcourt ・ Viscount Hardinge ・ Viscount Hatton ・ Viscount Hawarden ・ Viscount Head ・ Visco fuse ・ Visco Grgich ・ Visco, Friuli ・ Visco-elastic jets ・ Viscoelasticity ・ Viscoelasticity of bone ・ Viscofan ・ Viscom ・ Viscome ・ Viscometer ・ Viscomtat ・ Visconde de Mauá, Resende ・ Visconde do Rio Branco, Minas Gerais ・ Visconte ・ Visconte Maggiolo ・ Visconteo Castle (Locarno) ・ Visconti ・ Visconti (company) Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Visco-elastic jets ： ウィキペディア英語版 Visco-elastic jets Visco-elastic jets are the jets of viscoelastic fluids, i.e. fluids that disobey Newton’s law of Viscocity. A Viscoelastic fluid that returns to its original shape after the applied stress is released. Everybody has witnessed a situation where a liquid is poured out of an orifice at a given height and speed, and it hits a solid surface. For example – dropping of honey onto a bread slice, or pouring shower gel onto one's hand. Honey is a purely viscous, Newtonian fluid: the jet thins continuously and coils regularly. Jets of non-Newtonian Viscoelastic fluids show a novel behaviour. A viscoelastic jet breaks up much more slowly than a Newtonian jet. Typically, it evolves into the so-called beads-on-string structure, where large drops are connected by thin threads. The jet widens at its base (reverse swell phenomenon) and folds back and forth on itself .The slow breakup process provides the viscoelastic jet sufficient time to exhibit some new phenomena, including drop migration, drop oscillation, drop merging and drop draining. These properties are a result of the interplay of non-Newtonian properties (viscoelasticity, shear-thinning) with gravitational, viscous, and inertial effects in the jets. Free surface continuous jets of viscoelastic fluids are relevant in many engineering applications involving blood, paints, adhesives or foodstuff and industrial processes like fiber spinning, bottle-filling, oil drilling etc. In many of these processes, an understanding of the instabilities a jet undergoes due to changes in fluid parameters like Reynolds number or Deborah number is essential from process engineering point of view. With the advent of microfluidics, an understanding of the jetting properties of non-Newtonian fluids becomes essential from micro- to macro length scales, and from low to high Reynolds numbers7–9. Like other fluids, When considering viscoelastic flows, the velocity, pressure and stress must satisfy the mass and momentum equation, supplemented with a constitutive equation involving the velocity and stress. The temporal evolution of a viscoelastic fluid thread depends on the relative magnitude of the viscous, inertial, and elastic stresses and the capillary pressure. To study the inertio-elasto-capillary balance for a jet, two dimensionless parameters are defined: the Ohnesorge number (Oℎ) :$Oh=\backslash frac\{\backslash sqrt\{\backslash rho\; R\_0^3/\backslash gamma\}$. In these expressions, $\backslash rho$ is the fluid density, $\backslash eta\_0$ is the fluid zero shear viscosity, $\backslash gamma$ is the surface tension, $R\_0$ is the initial radius of the jet, and $\backslash lambda$ is the relaxation time associated with the polymer solution. == Mathematical Equations governing bead formation, filament thinning & breakup in weakly viscoelastic jets == -\frac}}|}} , where (z, t) is the axial velocity; $\backslash eta\_s$ and $\backslash eta\_p$ are the solvent and polymer contribution to the total viscosity, respectively (total viscosity $\backslash eta\_0=\backslash eta\_s+\backslash eta\_p$); $R\_z$ indicates the partial derivative $\backslash frac$ ; $\backslash sigma\_$ and $\backslash sigma\_$ are the diagonal terms of the extra-stress tensor. Equation (1) represents mass conservation, Equation (2) represents momentum equation in one dimension. Extra stress tensors $\backslash sigma\_$ and $\backslash sigma\_$ can be calculated as follows: +v\frac - 2\frac\sigma_) + \frac\sigma_^2 = 2\eta_p\frac|}} +v\frac + \frac\sigma_) + \frac\sigma_^2 = -\eta_p\frac|}} , where $\backslash lambda$ is the relaxation time of the liquid; $\backslash alpha$ is a positive dimensionless parameter corresponding to the anisotropy of the hydrodynamic drag on the polymer molecules and is called the mobility factor 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Visco-elastic jets」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.