| 摘要 |
A turbine blade has a labyrinth of internal channels (4,5,6,7,8) for the circulation of coolant received through an inlet integrally formed in a terminal portion of the blade root (1), the novel labyrinth geometry comprises; an inlet arranged on an axially upstream face of the terminal portion leading to an upstream duct portion (4) having a first section (4a) adjacent the inlet and a second section (4b), the second section (4b) having a reduced cross section compared to the first section (4a); a leading edge passage (5) intersecting the first section (4a) and extending through the blade body (3) towards the tip of the blade, a proximal end of the leading edge passage (5) being angled, in use, towards the direction of incoming air flow; a main blade passage (6) intersecting a downstream duct portion (7), the downstream duct portion arranged in axial alignment with the upstream duct portion (4) but separate from the upstream duct portion; and a restrictor passage (8) intersecting with the mid-blade passage (6) and extending towards a mid-blade duct portion (9), the mid-blade duct portion (9) in axial alignment with the upstream and downstream duct portions (4,7) and in fluid communication with the upstream duct portion (4). The main blade passage (6) is optionally a multi-pass. An optional multi-pass channel (23) can be machined between the downstream duct portion (7) and the mid-blade duct portion (9). Varying the diameter of the multi-pass channel (23) relative to the cross sections areas of intersections between the cast passages and ducts can adapt the coolant flow to suit changing blade end use requirements. |
