A numerical study on the influence of seal labyrinth on flow and heat transfer in a downstream rotating disk cavity

In typical aircraft engine structures, seal labyrinths are often used to control the inlet flow in rotating disk cavities. However, the presence of the seal labyrinth can significantly affect the downstream cavity flow and heat transfer. Therefore, this study employed numerical simulations to comparatively investigate the flow and heat transfer performance of disk cavities with and without labyrinth seal structures. The results indicated that the cooling air formed a jet after passing through the seal, which significantly increased both the radial velocity of the centrifugal flow and the swirl ratio in the downstream disk cavity. The changes in the flow structure led to variations in the heat transfer performance. Compared to the cavity without seal labyrinth, at an inlet mass flow rate of 0.18 kg/s, the cavity with seal labyrinth exhibited up to a 40 % increase in Nusselt number at the high radius, while showing a maximum decrease of 10 % at the low radius. The seal labyrinth also enhanced the downstream cavity's sensitivity to the inlet mass flow rate while reducing its sensitivity to rotational speed. In addition, the labyrinth tip clearance had a noticeable influence on heat transfer performance.