横向大剪切干涉应用于水平圆管自然对流换热

Natural convection heat transfer of horizontal cylinder with lateral shearing interferometry

将横向大剪切干涉技术扩展到温度检测以及传热分析等应用场合中,得到了大空间自然对流水平圆管壁温从400℃降至13℃的整个过程的实时干涉条纹,然后根据一维无限长假设反演出相应的温度场,最终得到了多个壁温下沿圆周各个方向的温度梯度值,并拟合了Rayleigh数和Nuave之间的准则关系式。实验结果表明虽然壁面0°附近部分真实条纹可能被圆管竖直倾角引发的阴影遮挡而造成条纹级数检测值有轻微误差,但这不会对换热分析造成显著影响。与文献中主流准则关系式对比可知,利用横向大剪切干涉技术仅需简单的后处理即可得到具有很高的时间、空间分辨率的自然对流换热的可信数据。研究结果为今后热管换热器的理论研究和工程应用提供了参考。

The real-time interferometric fringes of natural convection around horizontal circular cylinder in infinite space with different wall temperatures from 400℃ to 13℃ were obtained based on lateral shearing interferometry with large shearing quantity,which was applied to temperature measurement and heat transfer analysis.The inversion of corresponding temperature fields was completed according to the assumption of one-dimensional infinite length.The temperature gradients along circumferential direction at different wall temperatures and the fitting criteria relationship between Rayleigh number and average Nusselt number were obtained.The experimental results show that the shadow caused by circular cylinder vertical obliquity results in a slight error in the detection of true fringe series near the wall at the angles close to 0°,but it does not have a significant impact on the heat transfer analysis.The comparison of mainstream criteria relationships obtained in this study and in literature shows that the data of natural convection heat transfer with high time and spatial resolution can be obtained via simple post-processing.Reference for future theoretical research and engineering applications of heat pipe is provided.