| 摘要 |
<p>A gas turbine engine turbine (15) is provided with a casing (20) cooling system which operates in one of two conditions. In the first condition which is operational at engine cruise, all of the cooling air is initially directed on to a specific region (17) of the casing (20). Under full power conditions, some of the cooling air is directed on to the specific casing region (17) and the remainder directed on to the remainder of the casing (20). The cooling system operates to optimise turbine blade/casing radial clearances.</p> |
