Micro-scale Analysis of High Knudsen Number Flows

要描述罕见度， Knudsen数（Kn）由平均自由路径的比率（λ）由流动的特征维度（L）划分。根据Kn Exceeds 0.01的规定，我们不能将流动视为连续的一个，但必须将流动视为原子或分子的一个。我们将这些流量称为“大Kn”高Knudsen数流量，“其中correspond不只是用于低密度气体流量，但也可以用于小L的微型或纳米系统中的气体流量。在一个大的情况下，出现了一个强有力的非equilibrium现象，因为几个间分子集合。由于L非常小，在另一只手上，流动场受到分子与固体边界比间分子聚合物的相互作用的强烈影响。根据需要的原子或分子的光学测量技术，对热流体现象进行了与热流体现象有关的高昆德森数流量的实验分析，如它们的发射和吸收。Howe ... More ver， the experimental techniques are behind in development with the molecular simulation techniques。在此研究中，我介绍了一个resonantly enhanced multiphoton ionization （REMPI）方法和一个压力敏感的分子film （PSMF）。我们已经建立了2 R +2N_2-REMPI技术，在其中的硝基分子是由两个步骤电离化的。从地面状态到共振状态（2个光子）的第一步和从共振状态到电离状态（2个光子）的第二步。已经检测到的氮离子是一个信号，并依赖于辐射激光束的波长，通过Boltzmann绘图测量旋转温度。2 R +2N_2-REMPI技术应用于测量超声波自由分子硝基流动和获得P_0·D=15 Torr mm的非Boltzmann流动分布（P_0是源压力，D是nozzle直径）。压力敏感性绘画（PSP）具有潜在的压力测量工具，因为压力敏感性绘画的原理（PSP）技术是基于氧气检测的氧化剂检测的诊断工具，在高Knudsen数值规律中，由于压力敏感性绘画的原理。为了将PSP应用于微型设备，我们有使用PdoEP和PdMP的制造压力敏感分子薄膜（PSMF）的技术，并已测试这些PSMF以评估微型设备周围的压力测量的可行性。Less（低）

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