Numerical study of mixed and free convection heat transfer under ocean conditions

The mixed and free convection heat transfer of vertical upward flow under ocean conditions is studied numerically. The turbulent heat transfer in a smooth circular tube at low flow rates and the effects of ocean conditions are validated by experimental data. A CFD method based on the v 2-f turbulence model and additional inertial force is established. The analysis indicates that the effects of ocean conditions on heat transfer depend on the Buoyancy parameter. In particular, for the mixed convection regime, the overall heat transfer increases, and the local heat transfer deterioration is aggravated. The mixed and free convection heat transfer under ocean conditions is dominated by the Coriolis force and gravity, so the influence of rolling radius is weak. As the rolling period increases, the heat transfer variation increases due to the inclination effects. However, as the rolling amplitude increases, the heat transfer behavior is non-monotonic and difficult to predict due to the combined action of Coriolis effects and buoyancy effects. The introduction of pulsating flow breaks the symmetry of heat transfer, and the hot spot only appears on one side. The overall heat transfer increases, but the local heat transfer deterioration is further aggravated.(c) 2022 Elsevier Ltd. All rights reserved.