吸湿性PM颗粒呼吸道运动的CFD-DEM数值模拟与仿生实验

The high efficiency delivery of the inhalable drug particle in the respiratory system, which is proposed by the medical practice, is a new important project for the discipline of engineering thermophysics...Currently, researchers are optimistic about using the hygroscopic inhalable particle as the carrier to increase the deposition efficiency of the drug inhalant in lung. However, the reconstruction of the airway geometry and the recreation of airway temperature and humidity distributions as well as the simulation method are still imperfect in the research of hygroscopic particle. This application intends to reconstruct the realistic smooth upper airway model based on spiral CT scan by writing our own program; carry out the gas-solid two-phase flow simulation in the airway coupling with the heat transfer simulation within the airway boundary; develop the hygroscopic particle – vapor interaction model to simulate the hygroscopic growth of the particle in the airway; simulate the process of particle’s hygroscopic growth, transport and deposition on the particle scale based on the Computational Fluid Dynamics – Discrete Element Method (CFD- DEM), especially focusing on the particle – particle interaction and particle – fluid – particle interaction. Besides, this project plans to construct a bionic gas – solid two – phase flow experiment platform controlled by Programmable Logic Controller (PLC) to perform the particle deposition experiment under unsteady condition for the validation of the numerical model...This application is designed to reveal the mechanism. Furthermore, it is expected to form an innovative research approach and enrich the application and development of the gas – solid two – phase flow in the cutting – edge interdisciplinary research.

呼吸系统内吸入剂的高效输运是医学实践对工程热物理学科提出的重要基础研究新课题。..目前，以吸湿性可吸入颗粒物为载体，提高吸入剂入肺效率的方法被广泛看好，但现有吸湿性颗粒物研究在呼吸道模型重构、温度、湿度环境构建以及模拟方法方面尚不完善。本项目拟通过自编程序实现基于螺旋CT扫描的真实平滑上呼吸道重构；开展呼吸道内气固两相流动与边壁传热耦合模拟，正确反映呼吸道温度、湿度分布；构建吸湿性颗粒物-蒸气作用模型，模拟颗粒物在呼吸道内吸湿增长；基于CFD-DEM方法，从颗粒尺度模拟颗粒物在上呼吸道内吸湿增长、运动和沉积过程，关注过程中的颗粒-颗粒作用和颗粒-流场-颗粒作用。此外，构建PLC控制下的气固两相仿生实验平台，开展非稳态下的颗粒物沉积实验以验证数值模型。..本项目在预期揭示机理的同时，有望形成具有创新性的研究方法，丰富气固两相流在交叉前沿领域的应用和发展。

呼吸系统内吸入剂的高效输运是医学实践对工程热物理学科提出的重要基础研究新课题。.目前，以吸湿性可吸入颗粒物为载体，提高吸入剂入肺效率的方法被广泛看好，但现有吸湿性颗粒物研究在呼吸道模型重构、温度、湿度环境构建以及模拟方法方面尚不完善。.本项目通过自编程序，完成了基于螺旋CT扫描原始图像的预处理、轮廓提取、插值和点云提取以及三维重构，实现了真实平滑上呼吸道重构；开展呼吸道内气固两相流动与边壁传热耦合模拟，正确反映呼吸道温度、湿度分布，发现了呼吸道边界耦合传热传质对吸湿性颗粒物/液滴的沉积率影响可达10%；成功构建吸湿性颗粒物-蒸气作用模型，稳态模型验证误差约0.2%RH，非稳态模型验证误差约2%RH，实现了吸湿性颗粒物/液滴在呼吸道内蒸发、吸湿增长、输运和沉积的模拟；基于CFD-DEM方法，从颗粒尺度模拟颗粒物在上呼吸道内吸湿增长、运动和沉积过程，发现稀相条件下CFD-DEM方法的沉积率与CFD-DPM方法预测基本一致，浓相下可能受颗粒-流场-颗粒作用，沉积率明显提高。此外，成功构建PLC控制下的气固两相仿生实验平台，实现了任意前端呼吸道结构匹配和任意吸气波形生成，开展了呼吸道内的干颗粒沉积实验。.项目研究为基于吸湿性颗粒物方法的高效吸入药物以及高效吸入器的研发打下了坚实基础。