ACOUSTIC MEASUREMENT SYSTEM INCORPORATING A TEMPERATURE CONTROLLED WAVEGUIDE
First Claim
1. A measurement system for combustion gas in a gas turbine engine based on propagation of an acoustic signal while the gas passes through a measurement region in the engine, the system comprising:
- a waveguide having first and second ends and a cavity extending between the first and second ends of the waveguide, the first end configured to adjoin the flow path for injection of the acoustic signal into the measurement region; and
an acoustically transmissive physical barrier positioned between a portion of the waveguide and the measurement region to prevent movement of the combustion gas from the measurement region into the waveguide while permitting transmission of the acoustic signal from the waveguide into the measurement region.
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Accused Products
Abstract
For a gas turbine engine (10), a method and apparatus for determining temperature of combustion gas in a flow path (17) of the engine. In one embodiment a waveguide (30) includes a cavity (36) with a first waveguide end (32) including a barrier layer (58) which may be a membrane. With the first end positioned to inject an acoustic signal into the flow path, the barrier layer (58) isolates the cavity from combustion gas. Acoustic instrumentation positioned along the surface (38i) of a wall (38) of the waveguide provides generation and propagation of acoustic signals into the flow path for detection and measurement after reflection back into the cavity. The wall may include sections of two different materials, one material having a higher melting temperature than the other, or one material having greater electrically isolating properties than the other section.
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Citations
20 Claims
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1. A measurement system for combustion gas in a gas turbine engine based on propagation of an acoustic signal while the gas passes through a measurement region in the engine, the system comprising:
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a waveguide having first and second ends and a cavity extending between the first and second ends of the waveguide, the first end configured to adjoin the flow path for injection of the acoustic signal into the measurement region; and an acoustically transmissive physical barrier positioned between a portion of the waveguide and the measurement region to prevent movement of the combustion gas from the measurement region into the waveguide while permitting transmission of the acoustic signal from the waveguide into the measurement region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A gas turbine engine including an apparatus for controlling operation based on propagation of an acoustic signal while the gas passes through a measurement region a measurement region in the engine by determining time of flight information for an acoustic signal propagating through the measurement region, the engine comprising:
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a combustor section; a turbine section along which a flow path extends from the combustor section; a waveguide having first and second ends, with the first end adjoining the measurement region to enable injection of the acoustic signal into the flow path while the waveguide remains isolated from flow of the combustion gas therein, the waveguide including a barrier layer across the first end; and acoustic instrumentation providing the functions of an acoustic transmitter and a receiver positioned along an interior wall of the waveguide to generate the acoustic signal and to sense receipt of the acoustic signal after reflection from the measurement region. - View Dependent Claims (14, 15, 16)
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17. A waveguide for use in a gas turbine engine for determining time of flight information for propagation of an acoustic signal through a measurement region in a flow path carrying engine combustion gas, the waveguide comprising:
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a body comprising first and second ends and a tapered cavity extending between the first and second ends, with the first end comprising an acoustically transmissive physical barrier layer so that when the first end is positioned to adjoin the flow path to inject the acoustic signal into the flow path, the cavity remains isolated from flow of the combustion gas along the flow path; and acoustic instrumentation positioned to provide for generation of the acoustic signal and propagation of the acoustic signal into the measurement region. - View Dependent Claims (18, 19, 20)
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Specification