Micro-scale Analysis of High Knudsen Number Flows

高努森数流动的微观分析

• 批准号: 15206020
• 负责人: NIIMI Tomohide
• 金额: $ 30.78万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15206020/
• 关键词: Micro-Scale; High Knudsen Number Flows; REMPI; Gas-Surface Interaction; Free Molecular Flow; Langmuir-Blodgett Film; Non-Equilibrium; Temperature Measurement; 共鳴多光子イオン化法(REMPI); 面一分子干渉

To describe the degree of rarefaction, Knudsen number (Kn) is defined by the ratio of the mean free path (λ) divided by the characteristic dimension (L) of the flow. Provided that the Kn exceeds 0.01, we cannot approximate the flow as a continuum one, but have to perceive the flow as an atomic or molecular one. We call these flows with large Kn "High Knudsen number flows," which correspond not only to low density gas flows with large λ, but also to gas flows in micro- or nano-systems with small L. In the case of large λ, there appear the strong non-equilibrium phenomena because of few intermolecular collisions. For extremely small L, on the other hand, the flow field is strongly influenced by interaction of molecules with a solid boundary rather than intermolecular collisions. Experimental analyses of thermo-fluid phenomena related to the high Knudsen number flows need the optical measurement techniques based on atoms or molecules, such as their emission and absorption of photons. Howe … More ver, the experimental techniques are behind in development compared with the molecular simulation techniques.In this study, I introduce a resonantly enhanced multiphoton ionization (REMPI) method and a pressure sensitive molecular film (PSMF). We established the 2R+2 N_2-REMPI technique, in which nitrogen molecules are ionized by two steps, i.e., the first step from the ground state to the resonance state (2 photons) and the second step from the resonance state to the ionization state (2 photons). The nitrogen ions are detected as a signal and its spectra depending on the wavelength of an irradiated laser beam are analyzed to measure the rotational temperature through the Boltzmann plot. The 2R+2 N_2-REMPI technique is applied to measure the rotational population in supersonic free molecular nitrogen flows and obtain the non-Boltzmann rotational distribution for P_0・D=15 Torr mm (where P_0 is the source pressure and D is the nozzle diameter). The pressure-sensitive paint (PSP) has potential as a diagnostic tool for pressure measurement in the high Knudsen number regime because the principle of the pressure sensitive paint (PSP) technique is based on oxygen quenching of luminescence. Aiming to apply the PSP to micro devices, we have adopted Langmuir-Blodgett (LB) technique to fabricate pressure sensitive molecular films (PSMFs) using PdOEP and PdMP, and have tested these PSMFs to evaluate the feasibility of the pressure measurement around micro devices. Less

为了描述稀疏度的程度，knudsen数（kN）是由平均自由路径（λ）除以流量的特征尺寸（L）的比例。只要KN超过0.01，我们不能将流量近似为连续的流量，而必须将流量视为原子或分子。我们将这些流量称为“高knudsen数量流”，这不仅与具有大λ的低密度气流相对应，而且还对应于带有小L的微型或纳米系统中的气流。在较大的λ的情况下，由于少数几个间粒子碰撞，因此似乎存在强大的非平衡现象。另一方面，对于极小的L，流场受到分子与固体边界而不是分子间碰撞的相互作用的强烈影响。与高纳德森数量流有关的热流体现象的实验分析需要基于原子或分子的光学测量技术，例如它们的发射和照片的遗憾。与分子模拟技术相比，更多的是，实验技术是在开发中的落后之后。在这项研究中，我引入了一种共振增强的多光子电离（REMPI）方法和压力敏感的分子膜（PSMF）。我们建立了2R+2 N_2-REMPI技术，其中氮分子通过两个步骤电离，即，从基态到共振状态的第一步（2张照片）和从共振状态到电离状态的第二步（2张照片）。检测到氮离子为信号，其光谱取决于辐照激光束的波长，以测量通过Boltzmann图测量旋转温度。 2R+2 N_2-REMPI技术用于测量超音速无分子氮流中的旋转群体，并获得P_0 ・ d = 15 torr mm的非螺栓雄性旋转分布（其中P_0是源压力，D是源压力，D是喷嘴直径）。压力敏感的油漆（PSP）具有潜力作为高量标准型制度压力测量的诊断工具，因为压力敏感涂料（PSP）技术的原理基于发光的氧气淬火。为了将PSP应用于微型设备，我们采用了Langmuir-Blodgett（LB）技术，使用PDOEP和PDMP来制造压力敏感的分子膜（PSMFS），并测试了这些PSMF，以评估微型设备周围压力测量的可行性。较少的

项目成果

酸素感応膜及びその製造方法

氧敏感膜及其制造方法

• 发表时间: 2005

森英男, 新美智秀, 丹羽健二, 秋山勇雄: "REMPIによる超音速自由分子流における回転温度非平衡現象の解析に関する研究"日本機械学会論文集(B編). 69, 679. 623-629 (2003)

Hideo Mori、Tomohide Niimi、Kenji Niwa、Isao Akiyama：“使用 REMPI 分析超音速自由分子流中旋转温度非平衡现象的研究”日本机械工程师学会会刊（编辑 B）。 623-629（2003）

Application of Pressure Sensitive Luminophores for Micro- and Nano-systems

压敏发光体在微纳米系统中的应用

• 发表时间: 2005
• 期刊: IEEE International Symposium on Micromechanics and Human Science (MHS2005)
• 作者: Y.Matsuda;H.Mori;T.Niimi;H.Uenishi;M.Hirako
• 通讯作者: M.Hirako

Visualization of flow fields around clustered linear-type aerospike nozzles with sidewalls

带侧壁的线性型气动塞式喷嘴周围流场的可视化

• 发表时间: 2005
• 期刊: 5^<th> Pacific Symposium on Flow Visualization and Image Processing (PSFVIP-5)
• 作者: H.Mori;M.Taniguchi;R.Nishihira;T.Niimi
• 通讯作者: T.Niimi

Mori, H., Niimi, T., Yoshida, M., Kondo, M., Oshima, Y.: "Application of PSP to low density gas flows"Journal of Visualization. 7, 1. 55-62 (2004)

Mori, H.、Niimi, T.、Yoshida, M.、Kondo, M.、Oshima, Y.：“PSP 在低密度气流中的应用”可视化杂志。