12th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
Heat Transfer & Cooling
This paper investigates the impacts of wall heating conditions on heat transfer performace for a rotating channel with one side smooth and one side roughened by 45 degree inclined ribs. Previous experimental and numerical studies for only ribbed wall heated case showed that rotation has significantly negative impact on heat transfer performance. In order to investigate this uncommon behaviour, RANS simulations were conducted under three different wall heating conditions in present study: ribbed wall heated, all walls heated and adiabatic conditions. Numerical results show that the uneven wall heating condtions has negligible impact on stationary case, however, it has a large influence on rotational cases, in both the heat transfer and the fluid field. This is because in rotating cases, uneven heatings result in different buoyancy effects on trailing and leading walls that alter the main flow velocity profile. As a consequence, also secondary flows and heat transfer performance are affected.