A New Hue Capturing Technique for the Quantitative Interpretation of Liquid Crystal Images Used in Convective Heat Transfer Studies
A New Hue Capturing Technique for the Quantitative Interpretation of Liquid Crystal Images Used in Convective Heat Transfer Studies
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DOI：
10.1115/91-gt-122
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发表时间：
1991-06
期刊：
影响因子：
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通讯作者：
C. Camcı;Kui-soon Kim;S. A. Hippensteele
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文献类型：
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作者：
C. Camcı;Kui-soon Kim;S. A. Hippensteele
本研究的重点是一种新的图像处理为基础的彩色捕获技术的定量解释的液晶图像用于对流传热的研究。本方法对燃气涡轮机发动机中暴露于对流加热的表面是高度适用的。研究表明，在单晶模式下，传热表面上出现的许多颜色与局部温度密切相关。使用实验确定的线性色调与温度关系的非常精确的定量方法是可能的。从光源照射传热表面的强度、光源相对于传热表面的取向、晶层均匀性和工艺重复性等方面详细讨论了新的色调捕获工艺。该方法使用一个24位彩色图像处理系统，该系统在色调-饱和度-强度域中操作，这是使用红-绿-蓝颜色定义的传统系统的替代方案。本发明的方法比多重过滤器方法更有利，因为其能够以非常时间有效的方式从高分辨率的单晶图像同时产生许多等温线。目前的方法是有价值的，因为它直接应用于目前用于吸气式推进系统热段传热研究的稳态和瞬态传热技术。
This study focuses on a new image processing based color capturing technique for the quantitative interpretation of liquid crystal images used in convective heat transfer studies. The present method is highly applicable to the surfaces exposed to convective heating in gas turbine engines. The study shows that, in single crystal mode, many of the colors appearing on the heat transfer surface strongly correlate with the local temperature. A very accurate quantitative approach using an experimentally determined linear hue versus temperature relation is possible. The new hue capturing process is discussed in detail, in terms of the strength of the light source illuminating the heat transfer surface, effect of the orientation of the illuminating source with respect to the surface, crystal layer uniformity and the repeatability of the process. The method uses a 24 bit color image processing system operating in hue-saturation-intensity domain which is an alternative to conventional systems using red-green-blue color definition. The present method is more advantageous than the multiple filter method because of its ability to generate many isotherms simultaneously from a single crystal image at a high resolution, in a very time efficient manner. The current approach is valuable in terms of its direct application to both steady state and transient heat transfer techniques currently used for the hot section heat transfer research in air breathing propulsion systems.Copyright © 1991 by ASME