摘要:
A method for operating a pulse detonation system (50). The method includes providing a pulse detonation chamber (62) including a plurality of detonation tubes (58) extending therein, and detonating a mixture of fuel and air within each detonation tube such that at least a first tube is detonated at a different time than at least a second detonation tube.
摘要:
An active liner for attenuating noise includes a rigid backplate (26) supporting a piezoelectric panel (28). A pressure transducer (30) is disposed in the panel (28) for sensing acoustic pressure of noise being propagated against a face surface of the panel. A controller (36) includes a predetermined schedule of acoustic impedance for controlling a displacement driver (32) joined to the panel (28) to effect a displacement velocity of the panel face surface (28b) for obtaining a predetermined acoustic impedance at the sensed acoustic pressure for attenuating noise.
摘要:
An apparatus and method for suppressing dynamic instability in a bleed duct (42) of a gas turbine engine (10) includes a fan bypass duct (32) configured to permit a flow of air (28) through the gas turbine engine (10). The fan bypass duct (42) defines a fan duct surface (31), and the bleed duct (42) has an inlet (41) in fluid communication with the fan bypass duct (32) and a flow control valve (44) having an opened position and a closed position. A flow diverter (50) is positioned on the fan duct surface (31) proximate the inlet (41) of the bleed duct (42) and diverts the flow of air (28) from the inlet (41) when the flow control valve (44) is closed, while permitting a portion (57) of the flow of air (28) to enter the inlet (41) when the flow control valve (44) is opened.
摘要:
An apparatus and method for suppressing dynamic instability in a bleed duct (42) of a gas turbine engine (10) includes a fan bypass duct (32) configured to permit a flow of air (28) through the gas turbine engine (10). The fan bypass duct (42) defines a fan duct surface (31), and the bleed duct (42) has an inlet (41) in fluid communication with the fan bypass duct (32) and a flow control valve (44) having an opened position and a closed position. A flow diverter (50) is positioned on the fan duct surface (31) proximate the inlet (41) of the bleed duct (42) and diverts the flow of air (28) from the inlet (41) when the flow control valve (44) is closed, while permitting a portion (57) of the flow of air (28) to enter the inlet (41) when the flow control valve (44) is opened.
摘要:
A fan casing (10) for a gas turbine engine is provided which combines the functions of blade containment and noise suppression. The fan casing has an annular metallic inner shell (14) with a plurality of holes (17) are formed therethrough. An acoustic absorber (39), such as a cellular resonator, is disposed around the inner shell (14).
摘要:
A fan casing (10) for a gas turbine engine is provided which combines the functions of blade containment and noise suppression. The fan casing has an annular metallic inner shell (14) with a plurality of holes (17) are formed therethrough. An acoustic absorber (39), such as a cellular resonator, is disposed around the inner shell (14).
摘要:
The active liner comprises the rigid backplate, the piezoelectric panel having a back surface fixedly joined to the backplate, and an opposite face surface for directly facing the noise. The pressure transducer is disposed in the panel for sensing acoustic pressure of the noise being propagated against the panel face surface. A device electrically drives the panel to effect piezoelectric displacement of it in a direction normal to the panel face surface. A device is operatively joined to the pressure transducer and the driving device for controlling displacement of the panel face surface. The control device includes a predetermined schedule of acoustic impedance for controlling the driving device to effect a velocity of the panel face surface for the acoustic pressure for obtaining the predetermined acoustic impedance to attenuate the noise.
摘要:
An active liner for attenuating noise includes a rigid backplate (26) supporting a piezoelectric panel (28). A pressure transducer (30) is disposed in the panel (28) for sensing acoustic pressure of noise being propagated against a face surface of the panel. A controller (36) includes a predetermined schedule of acoustic impedance for controlling a displacement driver (32) joined to the panel (28) to effect a displacement velocity of the panel face surface (28b) for obtaining a predetermined acoustic impedance at the sensed acoustic pressure for attenuating noise.