On the Discontinuity of ε θ -the Dissipation Rate Associated with the Temperature Variance - at the Fluid-Solid Interface for Cases with Conjugate Heat Transfer

Cédric Flageul (1, 2) , Sofiane Benhamadouche (2) , Eric Lamballais (3) , Dominique Laurence (4) , Iztok Tiselj (1)

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

Conjugate heat transfer describes the thermal coupling between a fluid and a solid. It is of prime importance in industrial applications where fluctuating thermal stresses are a concern, e.g. in case of a severe emergency cooling (Pressurized Thermal Shock) or long-term ageing of materials (T junctions). For such complex applications, investigations often rely on experiments, high Reynolds RANS (Reynolds-Averaged Navier-Stokes) or wall-modelled LES (Large Eddy Simulation). However , experimental data on conjugate heat transfer are scarce as walls in lab rigs are often made of plexiglas and the transported scalar studied is often a dye. The development of RANS models for conjugate heat transfer is relatively recent, see Craft et al. [1]. In this paper, we establish that the dissipation rate associated with the temperature variance is discontinuous at the fluid-solid interface, in case of conjugate heat transfer. This discontinuity is verified using some DNS (Direct Numerical Simulation) of the turbulent channel flow with conjugate heat transfer. There is currently no RANS model for conjugate heat transfer that takes into account this discontinuity.

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

Cédric Flageul, Sofiane Benhamadouche, Eric Lamballais, Dominique Laurence, Iztok Tiselj. On the Discontinuity of ε θ -the Dissipation Rate Associated with the Temperature Variance - at the Fluid-Solid Interface for Cases with Conjugate Heat Transfer. 25th International Conference Nuclear Energy for New Europe (NENE 2016), Nuclear Society of Slovenia, Sep 2016, Portorož, Slovenia. ⟨hal-01456930⟩