Discussion on Measurement Mecha-nism of Pressure-Sensitive Paints
Discussion on Measurement Mecha-nism of Pressure-Sensitive Paints
复制标题
压敏涂料测量机理探讨
DOI：
10.1016/j.snb.2009.07.022
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
T. Niimi
中科院分区：
文献类型：
--
作者：
H. Yamaguchi;Y. Matsuda;T. Niimi
压敏涂料（PSP）是测量表面压力分布的一种非常有用的工具。一般来说，涂料测得的压力分布与压力水龙头测得的压力分布吻合得很好。油漆被认为代表热力学压力。近年来，该涂料已被应用于稀薄气体流动和微/纳米流动，即高克努森数状态，并显示出在大流量范围内测量压力的可行性。在本研究中，我们讨论了通过高克努森数状态测量从油漆发出的发光强度的物理意义。众所周知，在这种情况下，由于温度的跳变，压力水龙头与表面压力的关系很好，而与热力学压力的关系不太好。要求将高克努森数流视为分子流；因此，我们用分子动力学理论讨论了PSP的测量机理。用DSMC数值计算结果对PSP的压力分布进行了分析，验证了PSP反映的是表面压力。在连续流动条件下，对温度敏感性进行了详细的分析研究，讨论了“PSP测量的是压力，而不是密度”的建议[H]。Bell， E.T. Schairer， L.A. Hand， R.D. Mehta，使用发光涂层的表面压力测量，Annu。流体力学，33(2001):155-206。然而，从这些分析中，我们认为PSP测量了一些氧分子流向表面的通量。讨论了高努森数流中宏观流动对PSP的影响。
The pressure-sensitive paint (PSP) is a very useful tool to measure pressure distributions on surfaces. In general, a measured pressure distribution by the paint shows good agreement with that by pressure taps. The paint is considered to represent the thermodynamic pressure. Recently, the paint has been adopted to rarefied gas flows and micro/nanoflows, i.e. high Knudsen number regime, and exhibited feasibility of pressure measurement in wide range of flows. In this study, we have discussed the physical meaning of luminescent intensity emitted from the paint through high Knudsen number regime measurements. It is known that a pressure tap shows good agreement with surface pressure and not with thermodynamic pressure in this regime, because of the temperature jump. High Knudsen number flow is required to be treated as a molecular flow; thus we discussed the PSP measurement mechanism by the molecular kinetic theory. The pressure profile of PSP was examined by a DSMC numerical result, and it was verified that PSP indicates the surface pressure. The temperature sensitivity was also investigated analytically in detail in continuum flow regime to discuss the suggestion that “PSP measures pressure, not density” [H. Bell, E.T. Schairer, L.A. Hand, R.D. Mehta, Surface pressure measurements using luminescent coatings, Annu. Rev. Fluid Mech. 33 (2001) 155–206]. From these analyses, however, we suggest that PSP measures a number flux of oxygen molecules toward the surface. The effect of a macroscopic flow against PSP in high Knudsen number flow is also discussed.