Thermal performance in a rotating two-passage channel with various turning guide vanes

Abstract

Generally, significant changes are observed in heat transfer and pressure distribution with respect to the turning area of a rotating twopassage channel. Thus, the achievement of high heat transfer and low pressure loss in the turning area of a rotating two-passage channel is an important goal in the design of a high-efficiency cooling passage. This study explored the use of various guide vane arrangements in the turning area to achieve this goal. The study investigated heat transfer and pressure loss in the turning area of a rotating two-passage rectangular channel with various guide vanes. A naphthalene sublimation method was used to determine detailed local Sherwood number ratios (which can be converted to the heat/mass transfer coefficient). The pressure loss in the rotating channel was measured to calculate the thermal performance. The channel aspect ratios is 5 and hydraulic diameter is 26.67 mm. Additionally the Reynolds number was maintained constant at 10000, and the rotation number corresponded to 0.1. The results revealed that the turning flow in the turning area was largely influenced by the rotation effect. Furthermore, the turning flow was deflected towards the outer wall, and the centrifugal force induced a large flow separation region around the inner wall. This was in contrast to the results typically observed for a stationary channel. Among the various observed patterns of a turning guide vane, the inner guide vane case exhibited the best thermal performance in the rotating two-passage channel. The inner guide vane in the rotating two-passage channel guided the turning flow and helped in reducing the flow separation. This increased the thermal performance of the rotating two-passage channel.