Patent Application
20070220984
The present invention relates generally to temperature and/or pressure sensor assemblies, and more particularly to a temperature and/or pressure sensor assembly having a portion capable of being located in a compressor/fan inlet flow path.
Air temperature and/or pressure sensor assemblies are known which have a monolithic or a contiguous two part (an upstream part or shield and a downstream part) housing mounted to a fan hub frame of an aircraft gas turbine engine, which include leading and trailing edges located in a high-pressure-compressor/fan inlet flow path, and which include a sensor (such as a resistance temperature detector and/or a pressure transducer) which is located in or apart from the housing. The housing includes an opening which receives air from the compressor/fan inlet flow path, wherein the opening is in fluid communication with the sensor. In one example, the sensor is located in the housing and is in fluid communication with aspirated air from the compressor/fan inlet flow path. The leading and trailing edges of the housing are electrically heated during idle decent conditions to eliminate ice buildup on the housing. Air temperature sensor assemblies are also known which measure the fan inlet temperature, which open a bleed line valve when ice is detected on the housing to have compressor bleed air wash over the exterior of the housing to melt the detected ice, such bleed air then mixing with the fan inlet air, and such mixed air then encountering the temperature detector. It is noted that in a contiguous two part housing, the upstream part or shield minimizes ice accretion on the downstream part of the housing which includes the opening and may also include the sensor. Some known shields segment ice accretion into separate pieces, wherein each piece has a small mass which does not adversely affect downstream components of the engine.
Still, scientists and engineers continue to seek improved temperature and/or pressure sensor assemblies.
A first expression of an embodiment of the invention is a sensor assembly including a housing and a tube. The housing has a first leading edge portion which is capable of being located in a compressor/fan inlet flow path and which includes an interior wall section. The tube has a proximal portion and a distal portion. The proximal portion includes an air inlet which is adapted to receive a compressor bleed air flow. The distal portion is located in the housing and includes at least one air outlet hole. The at-least-one air outlet hole is spaced apart from the interior wall section and is aligned to direct at least some of the compressor bleed air flow to impinge against the interior wall section. The housing includes an opening which receives air from the compressor/fan inlet flow path when the housing is disposed in the compressor/fan inlet flow path, wherein the opening is adapted for fluid communication with a sensor, and wherein the sensor measures at least one of air temperature and air pressure.
In one example of the first expression of the embodiment of the invention, use of impinging compressor bleed air on an interior wall section of a leading edge portion is a more efficient heating method to prevent ice buildup than conventionally using heated air washed over the exterior of the housing or conventionally using an electrical heater to heat the leading and trailing edges of the housing.
The accompanying drawing illustrates an embodiment of the invention wherein:
Referring now to the drawing,
A leading edge portion of the housing 12 is a portion of the housing 12 disposed at and/or proximate a leading edge of the housing 12. It is noted that the compressor bleed air flow 30 is an air flow which has been heated by compression, and that, in one example, such heated air flow impinging against the interior wall section 22 will efficiently prevent ice buildup on the housing 12, as can be appreciated by those skilled in the art. In one example, the housing 12 is a monolithic housing. In another example, not shown, the housing is a contiguous multi part housing. In one variation, the multi part housing includes an upstream part or shield associated with the tube 14 and a downstream part contacting the shield and associated with the opening (such as an air scoop 43). In one modification, not shown, only a portion of the tube 14 is spaced apart from surrounding structure (note that the aft portion of the tube 14 in
In a first example, the sensor 16 measures air temperature and is disposed in the housing 12. In another example, not shown, the sensor includes an air temperature sensor portion disposed in the housing and an air pressure sensor portion disposed apart from the housing wherein a common or separate housing openings are associated with the two sensor portions and are adapted for total or static air pressure measurement by the air pressure sensor portion. In one enablement of the first expression of the embodiment of
In one application of the first expression of the embodiment of
In one implementation of the first expression of the embodiment of
In the same or a different implementation, the housing 12 includes a trailing edge 40 which is disposable in the compressor/fan inlet flow path 20, wherein the sensor 16 is disposed between the tube 14 and the trailing edge 40. In one variation, the distal portion 26 of the tube 14 is disposed proximate the first leading edge portion 18, and the sensor 16 is disposed proximate the leading edge 40. In one modification, the sensor 16 has its sensing tip 42 spaced apart from the surrounding housing 12 to provide thermal protection against heat from the tube 14, as can be appreciated by the artisan.
In one arrangement of the first expression of the embodiment of
In one configuration of the design having the air scoop 48, the housing 12 includes at least one spent-impingement-air exhaust hole 34 which is in fluid communication with at least some of the compressor bleed air flow 30 which impinged against the interior wall section 22 of the first leading edge portion 18 of the housing 12. In one example, when the first leading edge portion 18 is disposed in the compressor/fan inlet flow path 20, the air scoop 48 is disposed a greater distance into the compressor/fan inlet flow path 20 than is the at-least-one spent-impingement-air exhaust hole 34. This avoids any of the spent heated air from entering the air scoop 48 to adversely affect air temperature measurements, as can be appreciated by those skilled in the art. In one variation, the housing 12 includes first and second sides 50 and 52 extending from the first leading edge portion 18 to the trailing edge 40, the at-least-one spent-impingement-air exhaust hole 34 includes a first air exhaust hole 34′ disposed on the first side 50 and a second air exhaust hole 34″ disposed on the second side 52. In this variation, the first and second air exhaust holes 34′ and 34″ are disposed upstream from the sensor 16 allowing the exhausted spent heated air to mix with, and be cooled by, air in the compressor/fan inlet flow path 20 before passing the area of the housing 12 containing the sensor 16.
In one deployment of the first expression of the embodiment of
A second expression of the embodiment of
In one deployment of the second expression of the embodiment of
While the present invention has been illustrated by a description of several expressions of an embodiment, it is not the intention of the applicants to restrict or limit the spirit and scope of the appended claims to such detail. Numerous other variations, changes, and substitutions will occur to those skilled in the art without departing from the scope of the invention.
