三维燃烧火焰辐射成像模型及其构建算法

Radiative Imaging Model of Three-Dimensional Flame and Its Construction Method

基于辐射图像的燃烧温度场测量方法由于其系统简单、对被测对象无干扰等特点而受到广泛关注.该测量方法中建立准确的辐射成像模型以获得三维燃烧火焰发射和二维辐射图像间对应关系是温度场准确测量的前提.基于点扩散函数的透镜成像模型能够考虑三维燃烧火焰中聚焦平面内外发射点的不同成像特性,适用于不同的燃烧对象和辐射成像系统.针对现有成像模型构建算法在计算精度或计算时间上存在的不足,通过分析发射点在成像面上的能量分布函数,得到改进的辐射成像模型构建算法.以简化的三维燃烧火焰为研究对象,利用不同算法获得辐射图像并进行对比分析.结果表明,文中改进的辐射成像算法具有很好的计算精度,且计算效率高于蒙特卡罗方法.

The temperature field measurement method based on radiative images has attracted wide attention be-cause of its simplicity and no interference to the measured object.To obtain the relationship between the three-dimensional flame emission and the two-dimensional radiative image,an accurate radiative imaging model is nec-essary,and this is a prerequisite for the accurate temperature field measurement.The lens imaging model based on the point spread function can take into account the different imaging characteristics of the emission points inside and outside the focal plane,which is suitable for different combustion objects and radiative imaging systems.Aimed at the disadvantages of the existing construction method for imaging models in terms of computing accuracy or time consumption,an improved construction method to establish the radiative imaging model is developed by analyzing the energy distribution function of emission points on the image plane.A simplified three-dimensional flame is taken as a research object,and the radiative images obtained using different methods are compared and analyzed.Results show that the improved method has a good computing accuracy,and the computing efficiency is higher than that of the Monte Carlo method.