Response of an emulsion of leaky dielectric drops immersed in a simple shear flow: Drops more conductive than the suspending fluid
Response of an emulsion of leaky dielectric drops immersed in a simple shear flow: Drops more conductive than the suspending fluid
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DOI：
10.1063/1.2892635
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发表时间：
2008-04
影响因子：
4.6
通讯作者：
Arturo Fernández
中科院分区：
文献类型：
--
作者：
Arturo Fernández
直接数值模拟被用于研究当电场施加于体系时，漏电介质流体乳液的流变特性。由中性浮力液滴组成的乳液沉浸在简单剪切流中，且在平板之间施加电势差。假定液滴比悬浮流体更具导电性，并且液滴与悬浮流体之间的电导率之比$R = \sigma_i\ /\ \sigma_o$大于介电常数之比$S = \epsilon_o\ /\ \epsilon_i$。如果单个漏电介质液滴沉浸在电场中，这种性质组合会导致粘性流体从赤道向两极运动。乳液的响应取决于电力和流体剪切之间的竞争。这种关系通过梅森数$M_n = (3\lambda + 2)\mu\gamma\ /\ 6(\lambda + 1)\epsilon_0\beta^2 E_{\infty}^2$来量化。液滴可变形性的重要性通过电毛细管数$C_e = \epsilon_0\beta^2 E_{\infty}^2 a\ /\ \gamma$来衡量。微观结构和……
Direct numerical simulation is used to examine the rheological properties of an emulsion of leaky dielectric fluids when an electric field is applied to the system. The emulsion consisting of neutrally buoyant drops is immersed in a simple shear flow where an electric potential difference is applied between the plates. It is assumed that drops are more conductive than the suspending fluid and that the electrical conductivity ratio between the drops and the suspending fluid, R=σi∕σo, is larger than the dielectric permittivity ratio, S=eo∕ei. If a single leaky dielectric drop is immersed in an electric field, this combination of properties leads to a viscous fluid motion from the equator to the poles. The response of an emulsion depends on the competition between the electrical forces and the fluid shear. This relation is quantified by the Mason number, Mn=(3λ+2)μγ∕6(λ+1)e0β2E∞2. The significance of drop deformability is measured through the electric capillary number, Ce=e0β2E∞2a∕γ. The microstructure and ...