Abstract: An apparatus for controlling vibrations in a rotor stage rotating through core gas flow is provided. The apparatus includes a source of high-pressure gas and a plurality of ports for dispensing high-pressure gas. The rotor stage rotates through core gas flow having a plurality of circumferentially distributed first and second regions. Core gas flow within each first and second region travels at a first and a second velocity, respectively. The first velocity is substantially higher than the second velocity. The ports dispensing the high-pressure gas are selectively positioned upstream of the rotor blades, and aligned with the second regions such that high-pressure gas exiting the ports enters the second regions. The velocity of core gas flow in the second regions consequently increases, and substantially decreases the difference in core gas flow velocity between the first and second regions.

Abstract: An apparatus for controlling vibrations in a rotor stage rotating through core gas flow is provided. The apparatus includes a source of high-pressure gas and a plurality of ports for dispensing high-pressure gas. The rotor stage rotates through core gas flow having a plurality of circumferentially distributed first and second regions. Core gas flow within each first and second region travels at a first and a second velocity, respectively. The first velocity is substantially higher than the second velocity. The ports dispensing the high-pressure gas are selectively positioned upstream of the rotor blades, and aligned with the second regions such that high-pressure gas exiting the ports enters the second regions. The velocity of core gas flow in the second regions consequently increases, and substantially decreases the difference in core gas flow velocity between the first and second regions.

Abstract: A variable cycle gas turbine engine (10) includes a core unit (30) having a guide vane array (36), and a hybrid stage (38) with a rotor blade array (40) and a stator vane array (42). The engine is operable in at least two modes which channel different quantities of working medium air to the core unit, and each mode corresponds to a distinct thermodynamic cycle. The vanes (54) of the hybrid stage stator vane array are bivariable so that the leading segment (140) and trailing segment (146) of each vane are separately adjustable over a range of pitch angles. The bivariable character of the vanes ensures aerodynamic stability of the engine in each of its modes of operation.

Abstract: A diffuser for a radial-flow compressor with a circumferentially and radially extending annular splitter plate dividing the entrance portion of each diffusing passage into two parallel passages.