DNS of turbulent channel flow with conjugate heat transfer: effect of thermal boundary conditions on the second moments and budgets

Cédric Flageul (1) , Sofiane Benhamadouche (1) , Eric Lamballais (2) , Dominique Laurence (3, 1)

1 EDF R&D MFEE - Mécanique des Fluides, Energies et Environnement
2 PPrime [Poitiers] - Institut Pprime [UPR 3346]
3 MACE - School of Mechanical Aerospace and Civil Engineering [Manchester]

Budgets of turbulent heat fluxes and temperature variance obtained from the Direct Numerical Simulation of an incompressible periodic channel flow with a Reynolds number of 150 (based on friction velocity) and a Prandtl number of 0.71 are presented and analysed for four cases: locally imposed temperature at the wall (constant Dirichlet), locally imposed heat flux (constant Neumann), heat exchange coefficient (Robin) and 3D conjugate heat transfer. The dissi-pation rate associated with the temperature variance is strongly impacted by the thermal boundary condition. For non-conjugate cases, a straightforward analytical analysis establishes the connection between the boundary condition, the temperature variance and the wall-normal part of the thermal dissipation rate at the wall. For the conjugate case, the two-point correlations of the thermal field in the solid domain confirms the existence of very large scale thermal structures.

Mots clés: Direct Numerical Simulation; Channel flow; Robin; Conjugate heat transfer; second-moment closures; budgets

Domaines: Mécanique des fluides [physics.class-ph]

Cédric Flageul, Sofiane Benhamadouche, Eric Lamballais, Dominique Laurence. DNS of turbulent channel flow with conjugate heat transfer: effect of thermal boundary conditions on the second moments and budgets. International Journal of Heat and Fluid Flow, 2016, Special Issue devoted to the 10th Int. Symposium on Engineering Turbulence Modelling and Measurements (ETMM10) held in Marbella, Spain on September 17-19, 2014, 55, ⟨10.1016/j.ijheatfluidflow.2015.07.009⟩. ⟨hal-01321586⟩