Direct Numerical Simulation of Turbulent Heat Transfer with Slip and Temperature Jump

The fully developed turbulent flow and heat transfer in a plane channel at a nominal shear Reynolds number of 180 is studied via the direct numerical simulation technique. A linear velocity-slip boundary condition is assumed on one of the channel walls, whereas the classical no-slip condition is imposed on the other wall. The heat transfer at the slip wall is assumed to occur with and without temperature jump, whereas a classical first-kind temperature boundary condition is assumed on the no-slip wall. Various statistical quantities are shown and discussed. It is observed that the velocity fluctuations are attenuated in the proximity of the slip wall but they are amplified in the vicinity of the no-slip wall. The behavior is somewhat different for the temperature fluctuations. For the case without temperature jump, the temperature fluctuations are amplified near the slip wall, whereas they are attenuated close to the no-slip wall. For the case with temperature jump, the modifications of turbulent heat fluxes are more dramatic and they decrease by increasing the amount of wall slip. In general, the velocity slip condition will result in an enhanced heat transfer if no temperature jump is taken into account. This behavior is reversed when the temperature jump at the slip wall is taken into account. The budget of temperature variance is shown and discussed for the case with temperature jump.

Automated summary

The study focuses on fully developed turbulent flow and heat transfer in a plane channel with different velocity slip and no-slip conditions. It is found that velocity and temperature fluctuations behave differently, with temperature jump leading to reduced turbulent heat flux under velocity slip condition, enhancing heat transfer.