提出了一种建立非饱和土体宏-细观参数之间关系的方法,来建立在不同孔隙比和含水率等初始条件下非饱和土在不同应力路径下的离散元计算模型;通过编制离散元程序,基于接触粘结模型,对现有的PFC3D(Particle Flow Code in three dimensions...提出了一种建立非饱和土体宏-细观参数之间关系的方法,来建立在不同孔隙比和含水率等初始条件下非饱和土在不同应力路径下的离散元计算模型;通过编制离散元程序,基于接触粘结模型,对现有的PFC3D(Particle Flow Code in three dimensions)离散元程序进行改进,从而对在不同颗粒间粘结强度下的离散元试样进行一维固结的数值模拟试验来确定其结构屈服应力,并以结构屈服应力为桥梁建立颗粒间粘结强度随含水率变化的函数关系,最后建立能够反映真实非饱和土试样颗粒级配和在不同含水量下的离散元数值模型,为通过PFC3D等三维离散元软件研究非饱和土的基本力学特性提供思路.展开更多
To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics （CFD） simulations were conducted in the diseased triple-bifitrcation airways. Computations were ...To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics （CFD） simulations were conducted in the diseased triple-bifitrcation airways. Computations were carried out for twenty Reynolds numbers ranging from 100 to 2 000 in the step of 100. Particles in the size range of 1-10 μm were conducted. Two particle deposition mechanisms （gravitational sedimentation and inertial impaction） were considered. The results indicate that there are strong relationship between airflow structures and particle deposition patterns. Deposition efficiency is different for different particles in the whole range of the respiratory rates. Particles in different sizes can deposit at different sites. Smaller particles can be uniformly deposited at the inside wall of the considered model. Larger particles can be mainly deposited in the proximal bifurcations. Deposition fraction varies a lot for different inlet Reynolds numbers. For lower Reynolds numbers, deposition fraction is relatively small and varies a little with varying the diameters. For Reynolds number to target the aerosols at the specific site. higher Reynolds numbers, there is a most efficient diameter for each展开更多
文摘提出了一种建立非饱和土体宏-细观参数之间关系的方法,来建立在不同孔隙比和含水率等初始条件下非饱和土在不同应力路径下的离散元计算模型;通过编制离散元程序,基于接触粘结模型,对现有的PFC3D(Particle Flow Code in three dimensions)离散元程序进行改进,从而对在不同颗粒间粘结强度下的离散元试样进行一维固结的数值模拟试验来确定其结构屈服应力,并以结构屈服应力为桥梁建立颗粒间粘结强度随含水率变化的函数关系,最后建立能够反映真实非饱和土试样颗粒级配和在不同含水量下的离散元数值模型,为通过PFC3D等三维离散元软件研究非饱和土的基本力学特性提供思路.
基金Project(51178466) supported by the National Natural Science Foundation of ChinaProject(200545) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(2011JQ006) supported by the Fundamental Research Funds of the Central Universities of China
文摘To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics （CFD） simulations were conducted in the diseased triple-bifitrcation airways. Computations were carried out for twenty Reynolds numbers ranging from 100 to 2 000 in the step of 100. Particles in the size range of 1-10 μm were conducted. Two particle deposition mechanisms （gravitational sedimentation and inertial impaction） were considered. The results indicate that there are strong relationship between airflow structures and particle deposition patterns. Deposition efficiency is different for different particles in the whole range of the respiratory rates. Particles in different sizes can deposit at different sites. Smaller particles can be uniformly deposited at the inside wall of the considered model. Larger particles can be mainly deposited in the proximal bifurcations. Deposition fraction varies a lot for different inlet Reynolds numbers. For lower Reynolds numbers, deposition fraction is relatively small and varies a little with varying the diameters. For Reynolds number to target the aerosols at the specific site. higher Reynolds numbers, there is a most efficient diameter for each
