基于诱导电渗流的颗粒分选数值模拟研究

发布时间：2018-03-27 23:38

本文选题：颗粒分选　切入点：zeta电势　出处：《大连海事大学》2016年硕士论文

【摘要】：颗粒连续分选在多个领域具有重要的需求。为快速评价船舶压载水处理效果、鉴定压载水中微生物存活状态,开发一种能够根据生物相对介电常数差异的颗粒分选方法显得尤为迫切。此外,根据尺寸的差异分选滑油中不同粒径的磨粒,可为机械设备的保养维护和故障整修提供必要的信息。本文提出一种基于诱导电渗流进行颗粒分选的方法,即通过利用不同属性颗粒直流电场下形成的诱导电渗流强度不同,达到颗粒分选的目的。本文的主要研究内容如下：(1)基于电介质极化理论,研究了任意形状和介电常数颗粒的表面诱导zeta电势,推导得出了计算表面诱导zeta电势的数值求解表达式：并对其进行验证,证明了该表达式适用于任意表面形状、任意相对介电常数的电介质；(2)设计了基于诱导电渗流的颗粒连续分选系统,建立了颗粒分选模型中描述电场、流场、颗粒运动及固-液界面追踪等物理场的控制方程、边界条件及初始条件的数理模型,并对其分选性能进行了数值模拟研究,实现了基于颗粒尺寸和介电常数差异的连续分选；(3)获得了一个可表征颗粒周围诱导电渗流形成的涡与通道壁面相互作用强度的无量纲参数通过比较此参数与临界值的关系,能够准确预测不同颗粒在所设计通道中的流动方向。本文的研究对于发展相应的颗粒连续分选技术具有一定的指导意义。
[Abstract]:The continuous separation of particles has important requirements in many fields. In order to evaluate the effect of ballast water treatment on ships quickly and to identify the survival status of microorganisms in ballast water, It is particularly urgent to develop a method of particle separation according to the biological relative dielectric constant. In addition, according to the difference in size, the abrasive particles in the oil are separated with different particle sizes. This paper presents a method of particle separation based on induced electroosmotic flow (EOF), in which the induced electroosmotic strength is different by using different properties of particle DC electric field, which can provide necessary information for the maintenance and repair of mechanical equipment. The main contents of this paper are as follows: (1) based on the dielectric polarization theory, the surface induced zeta potential of particles of arbitrary shape and dielectric constant is studied. A numerical solution to calculate the surface-induced zeta potential is derived and verified. It is proved that the expression is suitable for arbitrary surface shapes. The particle continuous separation system based on induced electroosmotic flow is designed. The governing equations of describing the physical fields such as electric field, flow field, particle motion and solid-liquid interface tracing are established in the particle separation model. The mathematical model of boundary condition and initial condition, and its sorting performance are studied by numerical simulation. A dimensionless parameter which can characterize the intensity of vortex-wall interaction around particles is obtained by comparing the relationship between this parameter and the critical value, which is based on the difference of particle size and dielectric constant. The flow direction of different particles in the designed channel can be accurately predicted. The research in this paper has a certain guiding significance for the development of the corresponding particle continuous separation technology.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U664.92

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