高Ra数和极高Ra数Rayleigh-Bénard湍流热对流的物理和流动特性研究，对自然界和工业设计等领域的对流热输运科学问题研究具有极重要的意义。DNS模拟是研究湍流热对流的重要手段之一。本课题组创建的高效规模并行计算DNS直接求解方法PDM-DNS，可以在“天河二号”超级计算机上实现极高Ra数湍流热对流DNS模拟计算。在获得丰富的结果数据基础上，本课题将进行二维极高Ra数情况下Nu数和Re数对Ra数标度率及其变化的分析研究，讨论湍流热对流的“终极态”。开展系列Ra数和Pr数的温度边界层特性、流动结构变化、羽流形态及其运动特性以及对宏观传热规律的影响等二维和三维湍流热对流的物理特性及未知问题的具有挑战性研究工作。研究隔板对流装置传热倍增现象的物理规律。本课题的研究将为湍流热对流流动特性研究提供大量的定量信息，加深对高Ra数和极高Ra数湍流热对流传热规律和温度边界层物理规律的理解。

The researches of characteristics for the turbulent Rayleigh–Bénard convection at high and very high Ra number have very important significance for the research of the convective heat transport scientific problems in the nature and the designs for the industry. The direct numerical simulation (DNS) is one of the important means of turbulent convection. The Parallel Direct Method of DNS (PDM-DNS) was established by us and the DNS simulations for the turbulent convection with very high Ra number can be done on the “Tianhe 2” supercomputer. The present project proposed to conduct a great quantity of the DNS data for the turbulent convection.Based on the calculation results and data, the scaling law of the Nu number and Re number to the Ra number and its changes with the very high Ra number will be analyzed, and the “ultimate regime” will be discussed. The challenging researches of the physical characteristics and unknown problems for the 2D and 3D turbulent convection with different Ra number and Pr number will be done, such as the problems of the temperature boundary layer, the changes of the flow structure, the characteristics of plumes and their motion, and the effect on the heat transport law. The heat transfer multiple enhancement in the partitioned thermal convection will be discussed. The researches in present project will provide a large number quantitative information to illuminate the features of turbulent heat convection at high and very high Ra number.