Variable vane valve in a gas turbine

Abstract

In a gas turbine bypass engine having an inlet for gas flow to a core duct and an outer duct for bypassing a portion of the inlet air flow around such core duct, an improvement is provided in which a plurality of pivotal outlet guide vanes mounted on the rear frame member, aft of the low-pressure turbine, the vanes being hollow and upstanding edgewise in the path of the core gas with each vane mounted to pivot on an axis extending through the length thereof, with means to pivot the vanes on their axes so as to correct the swirl of turbine discharge gases toward axial flow through the nozzle of such engine, during high bypass ratio and low bypass ratio operation. The vanes are sized to extend from the rear frame into close clearance with a wall defining the inner surface of the engine bypass duct, which wall has a plurality of apertures therethrough between bypass duct and core duct to define an interduct connecting area, which apertures are sized, shaped and located to match the cross-sectional area of such vanes, so that such apertures can be at least partially blocked by such vanes when the latter are pivoted therebeneath into registration therewith.