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.

有关肺部质量和热量的三个相关项目 运输可扩散（气体）和不足的传输（气溶胶） 污染物将通过硬件实验和 应用数学分析。 总体目的是解决 肺部运输现象的方面是动机的 通过生理和临床环境，植根于碱性液体 力学。 具体而言，这三个主题是： I.体积循环振荡的实验研究 以刚性的气道分叉模型流动。 在这套 实验，一个激光多普勒风速计探针，由四个 激光束将在几个处转移到振荡流中 选定的横截面的网格点以本地 速度可以分解为其三维结构 周期中的特定时间。 利用此技术将增强 我们对轴向对流的作用的理解，次级漩涡 流，边界层的发展和稳定流中 常规和高频通风（HFV）。 此外， 稳定和不稳定的压力测量将被进行 描述了非线性阻抗的细节 涡流脱落，湍流和流动行为 流。 ii。 体积循环振荡流的理论研究 和大规模运输在灵活的通道中。 数学分析 将在柔性墙中包含的循环流量 为了确定管子合规性和壁运动的影响 在流体速度场，随后，关于 溶解物种的净轴向运输。 我们寻求依赖 deff在PE，Alpha，A和无量纲的管子上的合规性。 该分析将有助于发展对两者的理解 运输机制和振荡流和阻抗 正常气道和气道的特征 遵守。 iii。 体积循环振荡的实验研究 在灵活的通道中流动。 通过修改通道设备 在以前的实验中，我们将研究变形 受此流动状态的染料条纹。 稳定 通过我们的灵活性引起的流媒体将使用我们的 以前的技术，并将其与预测的流媒体进行了比较 II中的速度。 由于流媒体反映了特征 在不稳定的速度中，它提供了对预测的检查 不稳定的速度字段，在 分散。