PULMONARY MASS AND HEAT TRANSPORT

肺传质和传热

• 批准号: 3358632
• 负责人: JAMES Bernard GROTBERG
• 金额: $ 11.07万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1991-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3358632
• 关键词: computer simulation; environmental toxicology; heat; heterodyning; high frequency ventilation; mathematical model; model design /development; phantom model; respiratory airflow disorder; respiratory airflow measurement; respiratory airway pressure; respiratory airway volume; respiratory gas transport

Three related projects concerning pulmonary mass and heat transport for diffusible (gases) and poorly diffusible (aerosols) contaminants will be examined by hardware experiments and applied mathematical analysis. The overall aim is to address aspects of pulmonary transport phenomena which are motivated by physiological and clinical contexts and rooted in basic fluid mechanics. Specifically the three topics are: I. An experimental investigation of volume-cycled oscillating flow in a rigid, airway bifurcation model. In this set of experiments, a laser Doppler anemometer probe consisting of four laser beams will be directed into the oscillating flow at several grid points of selected cross sections in such a way that the local velocity may be resolved into its three dimensional structure at specific times in the cycle. Utilizing this technique will enhance our understanding of the role of axial convection, secondary swirl flows, boundary layer development and steady streaming in conventional and high-frequency ventilation (HFV). In addition, both steady and unsteady pressure measurements will be made to characterize the non-linear impedance with respect to details of the flow behavior such as vortex shedding, turbulence and streaming. II. A theoretical investigation of volume-cycled oscillating flow and mass transport in a flexible channel. A mathematical analysis of cycled flow contained by flexible walls will be carried out in order to determine the effect of tube compliance and wall motion on the fluid velocity field and, subsequently, on the predictions of net axial transports of dissolved species. We seek the dependence of Deff on Pe, alpha, A, and the dimensionless tube compliance. This analysis will assist in developing an understanding of both transport mechanisms and of oscillatory flow and impedance characteristics of normal airways and airways with altered compliance. III. An experimental investigation of volume-cycled oscillating flow in a flexible channel. By modifying the channel apparatus used in our previous experiments, we will study the deformation of dye streaks subjected to this flow regime. The steady streaming induced by flexibility will be measured using our previous techniques and compared to the predicted streaming velocities in II. Since the streaming reflects the characteristics of the unsteady velocities, it provides a check on the predicted unsteady velocity field which is of primary importance in dispersion.

三个有关肺肿块和热量的相关项目 可扩散（气体）和难扩散（气溶胶）的输送 污染物将通过硬件实验进行检查 应用数学分析。 总体目标是解决 肺部运输现象的各个方面 受生理和临床背景的影响，并植根于基础液体 机械师。 具体来说，这三个主题是： 一、体积循环振荡的实验研究 刚性气道分叉模型中的流动。 在这组 实验中，激光多普勒风速计探头由四个组成 激光束将在几个位置被引导到振荡流中 选定横截面的网格点，使得局部 速度可以分解为其三维结构 循环中的特定时间。 利用该技术将增强 我们对轴向对流、二次涡流作用的理解 流动、边界层发展和稳定流动 常规通气和高频通气 (HFV)。 此外， 将进行稳定和非稳定压力测量 表征非线性阻抗的细节 流动行为，例如涡流脱落、湍流和 流式传输。 二. 体积循环振荡流的理论研究 以及灵活渠道的大众运输。 数学分析 柔性壁包含的循环流将在 为了确定管顺应性和壁运动的影响 关于流体速度场，以及随后的预测 溶解物质的净轴向传输。 我们寻求依赖 Deff 对 Pe、α、A 和无量纲管顺应性的影响。 该分析将有助于加深对两者的理解 传输机制以及振荡流和阻抗 正常气道和改变气道的特征 遵守。 三． 体积循环振荡的实验研究 在灵活的通道中流动。 通过修改通道装置 在我们之前的实验中使用，我们将研究变形 受到这种流动状态的染料条纹。 稳定的 由灵活性引起的流将使用我们的测量 之前的技术并与预测的流媒体进行比较 II 中的速度。 由于流媒体体现了以下特点 对于非定常速度，它提供了对预测的检查 非定常速度场是最重要的 分散。