Clearance control apparatus for a bladed fluid flow machine

摘要

In a gas turbine engine the clearance between the tips of a row of rotor blades and the surrounding casing is maintained in a pre-determined range by providing supplies of relatively hot and cold air to passages in the casing. The amount of hot or cold air which is allowed to pass through the passages is controlled by exhausting the flow from the passages through a control clearance which varies in proportion to the size of the clearance to be controlled.