论文标题
气溶胶运输的微观力量
Microscopic force for aerosol transport
论文作者
论文摘要
单个颗粒衍射成像实验的关键成分是样品的成功递送。当前的样品传递方法基于气溶胶注射剂，其中样品是由流体动力学驱动的。这些通常是使用Stokes的阻力来模拟的，对于微米大小或较小的颗粒，应用了Cunningham校正因子。这不仅是不令人满意的，而且即使使用依赖温度的配方，也会在低温温度下失败。在这里，我们提出了基于爱泼斯坦公式的直接计算力的直接计算，该计算允许颗粒与气体的较高相对速度以及与气温不同的内部颗粒温度。新力量将斯托克斯的阻力重现了斯托克斯阻力已知的条件。此外，它在4 K处的实验表现出了极好的一致性，这证实了在较大温度范围内改善模拟的描述能力。
A key ingredient for single particle diffractive imaging experiments is the successful and efficient delivery of sample. Current sample-delivery methods are based on aerosol injectors in which the samples are driven by fluid-dynamic forces. These are typically simulated using Stokes' drag forces and for micrometer-size or smaller particles, the Cunningham correction factor is applied. This is not only unsatisfactory, but even using a temperature dependent formulation it fails at cryogenic temperatures. Here we propose the use of a direct computation of the force, based on Epstein's formulation, that allows for high relative velocities of the particles to the gas and also for internal particle temperatures that differ from the gas temperature. The new force reproduces Stokes' drag force for conditions known to be well described by Stokes' drag. Furthermore, it shows excellent agreement to experiments at 4 K, confirming the improved descriptive power of simulations over a wide temperature range.
