Influence of the Thermal and RANS Closures on Walls Heat Transfers Computations

ACTInternational audienceThis study deals with the heat transfer calculations between the internal walls of a duct and a non-isothermal turbulent flow inside this later on. The departure point for this work is the appearance of an asymmetry in the velocity fields, implying consequently a modification of the temperature profiles [1, 2]. Therefore, the fluid properties can be modified and the corresponding Reynolds numbers and associated non-dimensional distances to the wall (y+) can be significantly different from one side to another. We will first present the fluid and thermal modeling retained, using both an EB-RSM model with thermal GGDH closure and a k - e - v2/k model, i.e. two elliptic models either at order two or order one. Then, the heat transfers at the walls are computed on a 3D geometry consisting of a T\textendashjunction between a cylindrical pipe and a larger rectangular duct, whose flow are turbulent yet with different velocities. This type of devices corresponds usually to a part of a larger one involved in nuclear power plants