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.