PULMONARY MASS AND HEAT TRANSPORT

肺传质和传热

• 批准号: 3358637
• 负责人: JAMES Bernard GROTBERG
• 金额: $ 9.75万
• 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 1992-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3358637
• 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.

与肺肿块和肺热相关的三个项目 可扩散(气体)和难扩散(气溶胶)的传输 污染物将通过硬件实验和 应用数学分析。总体目标是解决 激发肺转运现象的几个方面 根据生理和临床情况，植根于基础液体 机械师。具体来说，这三个主题是： I.体积循环振荡的实验研究 刚性的、呼吸道分叉模型中的流动。在这套 实验中，激光多普勒风速计探头由四个部分组成 激光将以几个小时的速度进入振荡流动 选定横截面的网格点，以使局部 速度可以分解成其三维结构，在 周期中的特定时间。利用这项技术将增强 我们对轴向对流、二次涡流作用的认识 流动、边界层发展和定常流动 常规和高频通风(HFV)。此外, 定常和非定常压力测量都将用于 根据以下细节描述非线性阻抗 流动行为，如旋涡脱落、湍流和 流媒体。 II.体积循环振荡流的理论研究 并在灵活的通道中进行大规模传输。一种数学分析 由柔性墙包含的循环流动将在 以确定管子顺应性和壁面运动的影响 关于流体速度场，以及随后的预测 溶解物种的轴向净输运。我们寻求依赖 对Pe、α、A和无量纲管顺应性的定义。 这一分析将有助于加深对两者的理解 输运机制、振荡流动和阻抗 正常呼吸道和变态呼吸道的特点 合规性。 体积循环振荡的实验研究 在灵活的渠道中流动。通过修改通道设备 在我们之前的实验中，我们将研究变形 在这种流动状态下的染料条纹。稳重的 由灵活性引起的流将使用我们的 以前的技术，并与预测的流进行比较 速度在II。因为流反映了特征 在非定常速度中，它提供了对预测的检验 非定常速度场是最重要的 分散。