초록 ▼

A method for scheduling the flow of cooling air to a gas turbine engine achieves a varying clearance between the turbine blade tips and surrounding annular shroud responsive to the current engine power level. Excess clearance is provided during operation at less than maximum normal engine power to a

A method for scheduling the flow of cooling air to a gas turbine engine achieves a varying clearance between the turbine blade tips and surrounding annular shroud responsive to the current engine power level. Excess clearance is provided during operation at less than maximum normal engine power to accommodate the transient decrease in clearance following a step change in engine power level.

대표청구항 ▼

A method for modulating a cooling flow of air to a gas turbine engine operating within a power range, comprising the steps of determining a desired minimum clearance between a plurality of rotating blade tips within the gas turbine engine and a surrounding annular shroud; establishing a cooling air

A method for modulating a cooling flow of air to a gas turbine engine operating within a power range, comprising the steps of determining a desired minimum clearance between a plurality of rotating blade tips within the gas turbine engine and a surrounding annular shroud; establishing a cooling air flow rate schedule responsive to engine power within the power range, including the steps of (a) establishing a first cooling air flow rate corresponding to a maximum, steady state, engine power level within the power range, the first cooling air flow being sufficient to result in the blade tip to shroud clearance being equal to the determined minimum clearance; (b) determining, for each of a plurality of other engine power levels within the operating range, the magnitude of a corresponding transient clearance decrease resulting from a step change in engine power from the other engine power level to the maximum power level, and (c) establishing, responsive to the determined transient clearance displacement, a plurality of corresponding air flow rates for the plurality of other engine steady state power levels.