| 摘要 |
<p>A blade tip clearance control arrangement (25B) for a compressor (16) of a gas turbine engine (10) comprises a first annular control member (56) which defines a portion of the gas flowpath through the compressor and which is spaced from the tips of the rotor blades (32) by a clearance. The first annular control member (56) is positioned coaxially inwardly of a pair of second annular control members (48,50) and is secured thereto by a radially resilient annular support member (52). The first annular control member (56) is formed from a relatively low expansion material and the second annular control members are formed from a relatively high expansion material. Initially the first annular control member (56) expands rapidly in accordance with its own rate of thermal expansion against the resilience of the resilient annular support member (52), and the first annular control member (56) is caused to expand beyond its fully thermally expanded state by the second annular control members (48,50) and the resilient annular support member (52) in accordance with the rate of thermal expansion of the second annular control members.</p> |
