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US 10,119,477 B2Granted
Gas turbine engine with a multi-spool driven fan
AssigneeUnited Technologies Corporation
InventorsChristopher J. Hanlon, Daniel B. Kupratis, Walter A. Ledwith
Life of this patent
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Abstract
A gas turbine engine includes low and high spools constructed and arranged to rotate about an engine axis. The low spool drives at least one leading stage of a fan section and the high spool drives an aft stage of the fan section. The aft stage may generally include a bypass duct for controllably flowing a bypass stream directly from the leading stage and controllably and/or selectively into an auxiliary flowpath and/or into a second flowpath both located radially outward from a core flowpath.
Claims17
A gas turbine engine comprising:
- a high spool constructed and arranged to rotate about an engine axis;
- a low spool constructed and arranged to rotate about the engine axis;
- a fan leading stage connected for rotation to the low spool;
- a fan aft stage connected for rotation to the high spool;
- a fan outer housing axially aligned to and circumferentially surrounding the leading and aft stages;
- a fan inner housing spaced radially inward from the outer housing, located aft of the leading stage, and circumferentially surrounding the aft stage, wherein a bypass duct is defined by and radially between the outer housing and the inner housing for at least partially flowing air from the leading stage;
- a core case concentrically located about the engine axis, wherein a core flowpath is defined radially inward of the core case for flowing a core stream;
- a second case spaced radially outward of the core case, wherein a second flowpath is defined radially between the core and second case for flowing a second stream;
- and
- an outer case spaced at least in-part radially outward from the second case, wherein an auxiliary flowpath is defined at least in-part radially between the second and outer cases for flowing an auxiliary stream;
- wherein the bypass duct is in selective, direct communication with the second flowpath and the auxiliary flowpath such that air in the bypass duct is provided alternatively into the auxiliary flowpath or the second flowpath.
8 more elements
A gas turbine engine comprising:
- a low pressure turbine;
- a high pressure turbine proximate to the low pressure turbine;
- a first fan stage driven by the low pressure turbine and comprising a first fan blade, wherein the first fan blade includes a first airfoil that extends in span to a tip of the first fan blade;
- a second fan stage driven by the high pressure turbine and comprising a second fan blade, wherein the second fan blade includes a second airfoil that extends in span to a tip of the second fan blade, and the second airfoil is operable to receive air propelled by the first airfoil;
- a core flowpath through an engine core downstream of the second fan stage;
- a second flowpath radially outside of and surrounding the core flowpath;
- and
- an auxiliary flowpath radially outside of and surrounding the core flowpath and the second flowpath;
- wherein the second fan stage includes a bypass duct in direct, selective, communication between the auxiliary flowpath and the second flowpath, and the bypass duct is adapted to direct a bypass flow
- at least partially into the auxiliary flowpath, independent of the second flowpath, during a first mode of gas turbine engine operation;
- and
- at least partially into the second flowpath, independent of the auxiliary flowpath, during a second mode of gas turbine engine operation and
- wherein the bypass duct circumscribes the second fan blade such that air in the bypass duct bypasses the second fan stage.
10 more elements
A method of operating a gas turbine engine comprising the steps of:
- driving a leading stage of a fan section with a low spool;
- driving an aft stage of a fan section with a high spool;
- directing air from the leading stage to a bypass duct and to the aft stage, wherein the bypass duct circumscribes the aft stage of the fan section such that air in the bypass duct bypasses the second fan stage;
- directing air from the aft stage to a core flowpath through an engine core and a second flowpath that is radially outboard of and surrounding the core flowpath;
- controlling a valve arrangement to divert air flowing within the bypass duct out of the bypass duct and into the second flowpath during a first mode;
- and
- controlling the valve arrangement to divert air flowing within the second flowpath out of the second flowpath and into an auxiliary flowpath during a second mode, wherein the auxiliary flowpath is downstream of the bypass duct and radially outboard of and surrounding the second flowpath.
4 more elements
Dependencies are inferred from the claim text.