PULMONARY MASS AND HEAT TRANSPORT

肺质热相关三题 扩散性（气体）和扩散性差（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 肺转运现象的各个方面， 由生理和临床背景，并植根于基本流体 力学 具体而言，这三个专题是： I. 容积循环振荡的实验研究 刚性气道分叉模型中的流动。 的此集合中 实验中，激光多普勒风速计探头组成的四个 激光束将被引导到振荡流中， 选定横截面的网格点， 速度可以分解成它的三维结构， 周期中的特定时间。 利用这项技术将提高 我们对轴向对流、二次涡流 流动、边界层发展和定常流 常规和高频通气（HFV）。 此外，本发明还提供了一种方法， 将进行稳态和非稳态压力测量， 关于以下细节表征非线性阻抗： 流动特性，如旋涡脱落、湍流和 流.对于 二. 体积循环振荡流的理论研究 以及在柔性通道中的质量传输。 数学分析 的循环流所包含的柔性墙将进行 以确定管顺应性和室壁运动的影响 在流体速度场，随后，在预测的 溶解物质的轴向净输送。 我们寻求依赖 Deff对Pe、alpha、A和无量纲管柔度的影响。 这一分析将有助于发展对两者的理解 传输机制以及振荡流和阻抗 正常气道和改变的气道的特征 合规 三. 容积循环振荡的实验研究 在一个灵活的渠道。 通过修改通道装置 在我们以前的实验中使用，我们将研究变形 在这种流动状态下的染色条纹。 稳步 由灵活性引起的流将使用我们的 先前的技术并与预测的流传输相比较 速度在II。 由于流反映了 的非定常速度，它提供了一个检查的预测 非定常速度场是最重要的， 分散体

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.