Numerical predictions of turbulent heat transfer for air flow in rotating pipe

Heat transfer in fully developed turbulent pipe flow with isoflux condition imposed at the wall is investigated numerically by use of direct numerical simulation (DNS) and large eddy simulation (LES) for various rotation rates (0⩽N⩽7)(0⩽N⩽7) at a Reynolds number equal to 5500. To validate the present computations, predictions are compared to the results reported in the archival literature, and found to agree fairly well with them. With increasing rotation number, the temperature fluctuations decrease near the wall and are enhanced in the core region. The pipe rotation induces a reduction of the streamwise turbulent heat flux and an obvious augmentation of the azimuthal one, especially near the wall. Thus, heat transfer between fluid and wall is reduced. For higher rotation numbers (N>3)(N>3), the flow and the scalar transport become nearly insensitive to N. Joint probability density functions sketch the correlation between flow and thermal fields. Visualization of the temperature field exhibits the stabilizing effects of the centrifugal forces.