Control of Blade Tip-To-Shroud Leakage in a Turbine Engine By Directed Plasma Flow
AssigneeSiemens Energy, Inc.
InventorsDavid J. Wiebe, Matthew D. Montgomery
Life of this patent
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Abstract
An electrode (54) in the tip (31) of a turbine or compressor blade (30), and a series of electrodes (68) in a shroud (36, 64) that surrounds a rotation path (33) of the blade tip. As the blade tip reaches each shroud electrode, a controller (74) activates an electrical potential between them that generates a plasma-induced gas flow (76) directed toward the pressure side (PS) of the airfoil. The plasma creates a seal between the blade tip and the shroud, and induces a gas flow that opposes a leakage gas flow (52) from the pressure side to the suction side (SS) of the blade over the blade tip (31).
Claims13
An aerodynamic clearance control system comprising:
- an airfoil on a rotatable shaft, the airfoil comprising a tip;
- an electrode disposed at the airfoil tip;
- a shroud surrounding a rotation path of the airfoil tip;
- an electrode disposed at the shroud;
- and
- a controller that activates an electrical potential between the blade electrode and the shroud electrode when the blade electrode and shroud electrode are adjacent and offset;
- wherein the electrical potential is effective to produce a plasma-induced flow of a gas toward a pressure side of the airfoil.
An aerodynamic clearance control system comprising:
- a circular array of airfoils on a rotatable shaft, each airfoil comprising a pressure side, a suction side, and a tip;
- a shroud surrounding a rotation path of the airfoil tips, the shroud separated from the rotation path of the airfoil tips by a clearance;
- an electrode in the tip of each airfoil;
- a series of electrodes in the shroud;
- and
- a controller that activates an electrical potential between each airfoil tip electrode and each of the shroud electrodes in succession effective to generate a plasma-induced gas flow in the clearance that is directed toward the pressure side of the airfoil.
An aerodynamic clearance control system comprising:
- a circular array comprising a given number B of turbine or compressor airfoils, each airfoil comprising a pressure side, a suction side, a tip, and a rotation axis;
- a shroud surrounding a rotation path of the airfoil tips;
- a plasma generation system comprising an electrode on the tip of each airfoil and a series of electrodes in the shroud;
- and
- a controller that activates voltages in the shroud electrodes in one or more individually controllable sets, each set containing B number of shroud electrodes;
- wherein the voltages produce electrical potentials between the airfoil electrodes and respective adjacent ones of the shroud electrodes as the airfoil electrodes reach a given position relative to the respective adjacent shroud electrodes during a rotation of the circular array;
- and
- wherein the electrical potential generates a plasma-induced gas flow directed toward the pressure side of the airfoil in a clearance between the airfoil tip and the shroud.
Dependencies are inferred from the claim text.