Department of Chemical Engineering, Aristotle University of Thessaloniki, P.O. Box 472, 541 24 Thessaloniki, Greece.
Int J Pharm. 2013 May 1;448(1):205-13. doi: 10.1016/j.ijpharm.2013.03.004. Epub 2013 Mar 22.
In this work the steady-state flow in a commercial dry powder inhaler device, DPI (i.e., Turbuhaler) is described using computational fluid dynamics. The Navier-Stokes equations are solved using commercial CFD software considering different flow models, i.e., laminar, k-ε, k-ε RNG, and k-ω SST as well as large Eddy simulation. Particle motion and deposition are described using a Eulerian-fluid/Lagrangian-particle approach. Particle collisions with the DPI walls are taken to result in deposition when the normal collision velocity is less than a critical capture velocity. Flow and particle deposition, for a range of mouthpiece pressure drops (i.e., 800-8800 Pa), as well as particle sizes corresponding to single particles and aggregates (i.e., 0.5-20 μm), are examined. The total volumetric outflow rate, the overall particle deposition as well as the spatial distribution of deposition sites in the DPI are determined. The transitional k-ω SST model for turbulent flow was found to produce results most similar to a reference solution obtained with LES, as well as experimental results for the pressure drop in the DPI. Overall, the simulation results are found to be in agreement with the available experimental data for local and total particle deposition.
本文使用计算流体动力学（CFD）描述了商业干粉吸入器（DPI，即 Turbuhaler）中的稳态流动。通过商业 CFD 软件求解纳维-斯托克斯方程，考虑了不同的流动模型，即层流、k-ε、k-ε RNG 和 k-ω SST 以及大涡模拟。使用欧拉-流体/拉格朗日-粒子方法描述了颗粒的运动和沉积。当颗粒与 DPI 壁面的法向碰撞速度小于临界捕获速度时，认为颗粒会发生碰撞并沉积。研究了一系列喷口压降（800-8800 Pa）以及对应于单个颗粒和团聚体的颗粒尺寸（0.5-20 μm）下的流动和颗粒沉积情况。确定了总体积流出率、总颗粒沉积以及 DPI 中沉积部位的空间分布。发现对于湍流，过渡 k-ω SST 模型产生的结果与使用大涡模拟（LES）获得的参考解以及 DPI 压降的实验结果最相似。总的来说，模拟结果与局部和总颗粒沉积的现有实验数据一致。
