Modelling and numerical methods for nanoparticles in a gas phase

气相纳米颗粒的建模和数值方法

• 批准号: 310585209
• 负责人: Professor Dr. Steffen Hardt
• 金额: --
• 依托单位: Fachgebiet Nano- und Mikrofluidik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/310585209?language=en
• 关键词: Modelling; numerical; methods; nanoparticles; gas

The proposed project aims at the modeling and simulation of dynamical phenomena related to nanoparticles in a gas phase. It has a special relevance for processes of gas-phase synthesis of nanoparticles. One focus of the project will be on thermophoresis of particles and orientation effects occurring when these particles are deposited on a cold surface. Another important objective is a better understanding of the gas-kinetic interaction forces between particles that exchange mass with the gas. The resulting forces may support or prevent particle agglomeration. The models employed will include effects of temperature gradients, Brownian particle dynamics, and condensation/eva-poration/sublimation of molecules at the particle surface. As a special case, also droplets and their internal flow patterns will be modeled. On the one hand, (semi)analytical models will be employed to better understand some key processes related to gas-phase dynamics of nanoparticles. These models will rely on a number of simplifications compared to the full scenario. Detailed numerical simulations of nanoparticles in a gas will be the second pillar. For that purpose an existing Monte-Carlo simulator will be extended to account for particles with heterogeneous surfaces and phase change. In addition, for the simulation of droplets in a rarefied gas the Monte-Carlo code will be coupled to a Navier-Stokes solver.

该项目旨在对气相纳米粒子相关的动力学现象进行建模和模拟。它与纳米颗粒的气相合成过程具有特殊的相关性。该项目的重点之一是颗粒的热泳动以及这些颗粒沉积在冷表面上时发生的定向效应。另一个重要目标是更好地理解与气体交换质量的颗粒之间的气体动力学相互作用力。由此产生的力可以支持或防止颗粒聚集。所采用的模型将包括温度梯度、布朗粒子动力学以及粒子表面分子的冷凝/蒸发/升华的影响。作为一种特殊情况，还将对液滴及其内部流动模式进行建模。一方面，（半）分析模型将用于更好地理解与纳米颗粒气相动力学相关的一些关键过程。与完整场景相比，这些模型将依赖于许多简化。气体中纳米颗粒的详细数值模拟将是第二个支柱。为此，现有的蒙特卡罗模拟器将得到扩展，以考虑具有异质表面和相变的粒子。此外，为了模拟稀薄气体中的液滴，蒙特卡罗代码将与纳维-斯托克斯求解器耦合。

项目成果

Interaction of rigid body motion and rarefied gas dynamics based on the BGK model

• DOI: 10.3934/mine.2020010
• 发表时间: 2020
• 作者: S. Tiwari;A. Klar;G. Russo

A meshfree method for the BGK model for rarefied gas dynamics

稀薄气体动力学 BGK 模型的无网格方法

• DOI: 10.1007/s12572-019-00254-5
• 发表时间: 2019
• 期刊: International Journal of Advances in Engineering Sciences and Applied Mathematics
• 影响因子: 0.9
• 作者: S. Tiwari;A. Klar;G. Russo
• 通讯作者: G. Russo

Drag force on spherical particle moving near a plane wall in highly rarefied gas

• DOI: 10.1017/jfm.2019.921
• 发表时间: 2020-01-25
• 期刊: JOURNAL OF FLUID MECHANICS
• 影响因子: 3.7
• 作者: Goswami, P.;Baier, T.;Klar, A.
• 通讯作者: Klar, A.

Thermophoresis of Janus particles at large Knudsen numbers

• DOI: 10.1103/physrevfluids.3.094202
• 发表时间: 2018-09-12
• 期刊: PHYSICAL REVIEW FLUIDS
• 影响因子: 2.7
• 作者: Baier, Tobias;Tiwari, Sudarshan;Hardt, Steffen
• 通讯作者: Hardt, Steffen