| 摘要 |
A cooling air flow control device for a gas turbine engine comprises a cooling passage 76 defined within a component 50 and a shaped memory metal valve 114 disposed in the passage 76 to regulate, in use, the flow rate of a cooling air flow supplied through the passage 76 wherein the valve 114 operates by changing shape to control the cooling air flow rate in response to the temperature of the component 50. The valve 114 may be a disc which dilates (fig 4A) or distorts (fig 4B), or a plate (122, fig 5A,5B) or series of plates (122, fig 6A,6B) which distort. A plurality of valves (114, fig 8) which dilate or distort at different temperatures may be arranged in series in the passage 76. The component 50 may be a blade, vane disc, casing or bearing chamber or heat exchanger. The valve 114 may switch shape at a given temperature, or change shape gradually over a temperature range.
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