Flow and Heat Transfer in an Axial Throughflow Rotating Disk Cavity with Dual Inlets Under Variable Conditions

The flow and heat transfer in a rotating disk cavity with dual axial inlets are investigated under a range of operating conditions. A full 360° computational fluid dynamics model is employed, with 40 simulation cases varying the rotational Reynolds number ( Re ω = 1.9 × 10 6 –3.1 × 10 6 ) and axial throughflow Reynolds number ( Re z = 7.3 × 10 5 –1.2 × 10 6 ). The results show that elevated rotation intensifies turbulent mixing and significantly enhances convective cooling on the upstream disk, whereas increasing throughflow improves heat transfer on the downstream disk by promoting deeper coolant penetration. However, an excessive axial flow rate can induce local thermal stratification near the upstream disk, which offsets its heat transfer gains, and strong rotation diminishes the marginal benefits of higher throughflow on downstream cooling. Overall, the study reveals distinct cooling behaviors on the upstream and downstream disk surfaces governed by the interplay between rotation and throughflow. These findings provide insight into optimizing dual-inlet cavity designs and underscore the importance of balancing rotational speed and coolant flow distribution for effective thermal management in gas turbine disk cavities.