Imaging Technology of Surface Pressure Distribution using Luminescent Coatings

研究了利用发光涂层对气动模型表面压力分布进行成像的技术。我们改进了阳极氧化铝压敏漆（AA-PSP），这是一种用于测量非稳态压力波动的最先进的油漆。在此基础上，发展了一种软凝胶法测量表面应力场的技术。(1)感压涂料是用发光染料与其粘合而成的。发光强度取决于粘合剂中的氧浓度。由于阳极氧化铝的多孔结构具有很大的气体扩散性，染料吸附在孔的表面上，AA-PSP具有相当快的响应特性。然而，阳极氧化铝表现出亲水性，这导致AA-PSP响应中严重的潮湿敏感性。我们通过在阳极氧化铝上涂覆两亲分子以及发光染料来降低湿敏性。我们用链烷酸作为两性物质 关于我们 hic分子。我们成功地将潮湿敏感性降低到原始AA-PSP敏感性的四分之一。在此基础上，利用疏水AA-PSP测量了三角翼跨音速非定常压力脉动。我们在1 kPa的不确定度内捕获了频率为1 kHz的压力波动。(2)提出了一种在任意表面上涂覆多孔氧化铝的方法。以醇铝为原料，采用溶胶-凝胶法（Yoldas法）制备了多孔氧化铝。通过在氧化铝溶胶中加入聚乙二醇，制备了多孔结构的氧化铝溶胶。压敏性与阳极氧化铝PSP相当。(3)我们开发了一种智能薄膜来测量表面应力场。根据弹性力学理论，可以从薄膜的变形量来估计薄膜的应力场。必须仔细选择薄膜的弹性，以检测少量的应力。我们用明胶和发光的细粉。从荧光粉的图像中成功地估算了厚度和剪切变形，但计算的应力值仍有相当大的误差。需要进一步改进以计算表面上的应力的全场测量。少

We studied the imaging technology of surface pressure distribution on the aerodynamic models using luminescent coatings. We improved the anodized aluminum pressure sensitive paint (AA-PSP), which is a state-of-the-art paint for measuring unsteady pressure fluctuations. Furthermore, we developed a measuring technique of surface stress field using soft gel.(1) The pressure-sensitive paint is luminescent dyes with their binder. The intensity of the luminescence depends on the oxygen concentration in the binder. The AA-PSP has a quite fast-responding characteristic due to large gas diffusivity of the porous structure of the anodized aluminum, in which the dyes are adsorbed on the surface of pores. The anodized aluminum, however, exhibits a hydrophilic property, which causes a severe humid sensitivity in the response of the AA-PSP. We reduced the humid sensitivity by coating amphipathic molecules on the anodized aluminum as well as the luminescent dyes. We used the alkanoic acid as amphipat … More hic molecules. We successfully reduced the humid sensitivity to a quarter of the sensitivity of original AA-PSP. Then we measured unsteady pressure fluctuation on the delta wing in transonic flow using the hydrophobic AA-PSP. We captured the pressure fluctuation having a frequency of 1 kHz within the uncertainty of 1 kPa.(2) We developed a coating method of porous alumina on arbitrary surface. We successfully made the porous alumina via a sol-gel route (Yoldas method) using an aluminum alcoxide as the material. The porous structure was achieved adding polyethylene glycol in the alumina sol. The pressure-sensitivity is equal to that of the anodized aluminum PSP.(3) We developed a smart film to measure the surface stress field. The stress filed can be estimated from the deformation of the film based on the theory of elasticity. The elasticity of the film must be chosen carefully to detect the small amount of the stress. We used gelatin with luminescent fine powders. The thickness and shear deformation were successfully estimated from the images of the luminescent fine powders, although there still remain considerable errors in the calculated stress value. Further improvement was needed to calculate full-field measurement of the stress on the surface. Less