Acoustic termination for a pressure monitoring system

Abstract

Aspects of the invention relate to an improved acoustic termination for a pressure monitoring system. The termination can include an inner tube having a passage extending therethrough. One end of the inner tube can extend into an open end of an outer tube, which is closed at its opposite end. The portion of the inner tube that extends into the outer tube can include a plurality of apertures. Sound absorption material can fill the space between the outer tube and the portion of the inner tube extending therein. A pressure signal entering the acoustic termination can be substantially dissipated and can minimize signal reflection from the termination. As a result a more accurate pressure measurement can be obtained by a pressure measurement device that operatively connects to the passage upstream of the termination.

1 . An acoustic termination for a pressure monitoring system comprising: 
 an outer tube having an at least partially open first end and a closed second end, the outer tube having an interior, wherein at least a portion of the interior is filled with sound absorption material; and    an inner tube having an open inlet end and an open termination end, the inner tube further having an outer peripheral surface and an inner peripheral surface, the inner peripheral surface defining a passage extending through the inner tube, the inner tube operatively engaging the first end of the outer tube such that the passage is in fluid communication with the interior of the outer tube;    whereby a pressure signal transmitted through the inner tube is received within the interior of the outer tube and dampened by engagement with the sound absorption material.    
     
     
         2 . The acoustic termination of  claim 1  wherein the sound absorption material is fiberglass.  
     
     
         3 . The acoustic termination of  claim 1  wherein the first end of the outer tube provides an opening sized to allow passage of the inner tube such that the opening substantially engages the outer peripheral surface of the inner tube.  
     
     
         4 . The acoustic termination of  claim 1  wherein the inlet end of the inner tube is connected to a pressurized chamber.  
     
     
         5 . The acoustic termination of  claim 4  wherein the pressurized chamber is the combustor of a gas turbine engine.  
     
     
         6 . The acoustic termination of  claim 1  further including: 
 a pressure measurement device operatively connected in branched relation to the passage, whereby the pressure measurement device determines pressure when it is engaged by a pressure signal in the passage.    
     
     
         7 . The acoustic termination of  claim 6  wherein the pressure measurement device is a pressure transducer.  
     
     
         8 . The system of  claim 1  wherein the termination end of the inner tube is positioned substantially proximate the first end of the outer tube, wherein a chamber is defined within the sound absorption material such that the passage of the inner tube is in fluid communication with the chamber, whereby a pressure signal exiting the inner tube is received within the chamber.  
     
     
         9 . The system of  claim 1  wherein a portion of the inner tube including the termination end extends into the first end of the outer tube, wherein the inner tube includes a plurality of apertures only in the portion of the inner tube that extends into the outer tube, and wherein the sound absorption material is provided in the space between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube and the termination end of the inner tube and the second end of the outer tube.  
     
     
         10 . A pressure monitoring system comprising: 
 a pressurized chamber containing at least one pressure signal;    an outer tube having an at least partially open first end and a closed second end, the outer tube having an interior, wherein at least a portion of the interior is filled with sound absorption material; and    an inner tube having an open inlet end and an open termination end, the inner tube further having an outer peripheral surface and an inner peripheral surface, the inner peripheral surface defining a passage extending through the inner tube, the inner tube operatively engaging the first end of the outer tube so as to be in fluid communication with the interior of the outer tube;    whereby a pressure signal transmitted through the inner tube is received within the interior of the outer tube and dampened by engagement with the sound absorption material.    
     
     
         11 . The system of  claim 10  wherein the pressurized chamber is the combustor of a gas turbine engine.  
     
     
         12 . The system of  claim 10  wherein the sound absorption material is fiberglass.  
     
     
         13 . The system of  claim 10  wherein the termination end of the inner tube is positioned substantially proximate the second end of the outer tube, wherein a chamber is defined within the sound absorption material such that the passage of the inner tube is in fluid communication with the chamber, whereby a pressure signal exiting the inner tube is received within the chamber.  
     
     
         14 . The system of  claim 10  wherein a portion of the inner tube including the termination end extends into the first end of the outer tube, wherein the inner tube includes a plurality of apertures only in the portion of the inner tube that extends into the outer tube, and wherein the sound absorption material is-provided in the space between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube and the termination end of the inner tube and the second end of the outer tube.  
     
     
         15 . The acoustic termination of  claim 10  further including: 
 a pressure measurement device operatively connected in branched relation to the passage, whereby the pressure measurement device determines pressure when it is engaged by a pressure signal in the passage.    
     
     
         16 . The acoustic termination of  claim 15  wherein the pressure measurement device is a pressure transducer.  
     
     
         17 . A pressure monitoring system comprising: 
 an outer tube having an at least partially open first end and a closed second end, the outer tube having an inner peripheral surface;    an inner tube having an open inlet end and an open termination end, the inner tube further having an outer peripheral surface and an inner peripheral surface, the inner peripheral surface defining a passage extending through the inner tube, wherein a portion of the inner tube including the termination end extends into the first end of the outer tube, wherein the inner tube includes a plurality of apertures only in the portion of the inner tube that extends into the outer tube;    a pressure measurement device operatively connected in branched relation to the passage; and    sound absorption material provided in the space between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube and the termination end of the inner tube and the second end of the outer tube,    whereby a pressure signal transmitted through the inner tube engages the pressure measurement device so that the device determines pressure, and whereby the pressure signal is substantially dampened by engagement with the sound absorption material after exiting the inner tube through the apertures and the termination end.    
     
     
         18 . The system of  claim 17  wherein the inlet end of the inner tube is connected to the combustor of a gas turbine engine.  
     
     
         19 . The system of  claim 17  wherein the sound absorption material is fiberglass.  
     
     
         20 . The system of  claim 17  wherein the pressure measurement device is a pressure transducer.