Heat transfer characteristics of a submerged jet impinging axisymmetrically onto a rotating disk

In this paper, the heat transfer characteristics of a submerged jet impinging axisymmetrically onto a rotating disk is investigated numerically using a Reynolds stress turbulence model with elliptic blending. The heat transfer is characterized based on the effects of jet Reynolds number, rotational Reynolds number and Prandtl number. Key flow field features and the drag experienced by the rotating disk are also studied. Rigid body rotation of the disk is captured using a moving mesh approach and is compared with a traditional moving reference frame approach. It was found that the moving mesh approach provided a solution that was more uniform about the axis of rotation, however when considering the average heat transfer, there is less than a 1 % difference between moving reference frame and moving mesh predictions. A clear distinction between the jet dominated, transition and rotation dominated flow regimes is made. With increasing jet Reynolds numbers and decreasing rotational Reynolds numbers, the jet dominated flow regime spatially grows about the axis of rotation and the rotation dominated flow regime shifts downstream from the axis of rotation. Jet and rotation dominated heat transfer regimes were identified and the transition point between the two regimes shifts radially outwards from the axis of rotation as the jet Reynolds number increases. The trade-off between heat transfer enhancement and drag on the disk was explored by studying the wall shear stress. A continuous increase in the wall shear stress along the radius of the disk was observed when the rotational Reynolds number was high due to a strong influence of the circumferential component of the wall shear stress. A correlation for the average heat transfer was also proposed based on the jet Reynolds number, rotational Reynolds number and Prandtl number.