Nanoparticle Coagulation in a Planar Jet
Nanoparticle Coagulation in a Planar Jet
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DOI：
10.1080/02786820490247669
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发表时间：
2004-01
影响因子：
5.2
通讯作者：
S. Miller;S. Garrick
中科院分区：
文献类型：
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作者：
S. Miller;S. Garrick
对纳米颗粒在平面射流中的凝聚过程进行了直接数值模拟。粒子场采用分段法近似气溶胶动力学方程。该方法是有利的，因为没有关于颗粒尺寸分布的先验假设，并且与非定常Navier-Stokes求解器相结合，它以准确的方式提供了颗粒场的时空演化。射流由包含直径为1 nm的颗粒的不可压缩流体组成，该流体进入无颗粒的同向流动流。解决了10个部分，允许粒子场发展到8 nm的直径。结果表明，几何标准差在喷嘴下游一个射流直径内达到自保持值，并保持在该值高达7.5个射流直径。在该近端区域中，颗粒尺寸在整个射流中相对均匀。进一步下游，大规模的旋涡结构的影响是增加的区域内的颗粒的停留时间和扰动的几何标准偏差超过自我保护的值。
Direct numerical simulation of nanoparticle coagulation in a planar jet is performed. The particle field is represented using a sectional method to approximate the aerosol general dynamic equation. The methodology is advantageous in that there are no a priori assumptions regarding the particle size distribution and coupled with an unsteady Navier-Stokes solver, it provides the spatio-temporal evolution of the particle field in an accurate manner. The jet consists of an incompressible fluid containing particles 1 nm in diameter issuing into a particle-free coflowing stream. Ten sections are solved allowing the particle field to develop to 8 nm in diameter. Results show that the geometric standard deviation reaches the self-preserving value within one jet diameter downstream of the nozzle and remains at that value up to 7.5 jet diameters. In this proximal region, the particle size is relatively uniform throughout the jet. Further downstream, the effects of large-scale vortical structures is to increase the residence time of particles within the domain and perturb the geometric standard deviation beyond the self-preserving value.