A three-dimensional direct simulation was carried out to examine the natural convective fluid flow and heat transfer characteristics in a long enclosure with a twisted cylinder. The effects of the Rayleigh number, dimensionless mean radius, and wavelength (or wavenumber) for a twisted cylinder were investigated. In addition to the heat transfer characteristics at cylinder and enclosure, the distributions of temperature and fluid flow are also presented by the iso-surfaces of temperature and vortical structure formed inside the enclosure. An artificial neural network was applied to predict the characteristics of natural convective flow and heat transfer by considering various simulation parameters for the elliptical and twisted cylinders. The input parameters considered in this study significantly affect on the heat transfer characteristics at cylinder and enclosure.

进行了三维直接模拟，以检查带有扭曲圆柱体的长外壳中的自然对流流体流动和传热特性。研究了扭曲圆柱体的瑞利数，无量纲平均半径和波长（或波数）的影响。除了圆柱体和外壳的传热特性外，温度和流体流量的分布还由外壳内部形成的温度等值面和涡旋结构表示。通过考虑椭圆形和扭曲圆柱体的各种模拟参数，将人工神经网络应用于自然对流流动和传热特性的预测。