Combustor

Abstract

A combustion method and combustor for use in a jet engine, the jet engine having a compressor portion and a turbine portion. The combustor includes an outer tube having a central axis that extends longitudinally intermediate the compressor portion and turbine portion and is positioned to receive air discharged by the compressor portion. An inner tube is positioned within the outer tube that includes an associated outer surface spaced from the inner surface of the outer tube thereby defining a combustion chamber. The outer tube and inner tube include fluid directing structure for communicating at least some of the air discharged by the compressor portion to the combustion chamber. The fluid directing structure directs air into the combustion chamber in a direction offset from the central axis, thereby causing rotation or swirling of the air about the central axis.

Having described the invention, the following is claimed: 
     
         1 . A jet engine comprising:
 a housing having a first end and a second end and an interior passage that extends from the first end to the second end;   a compressor positioned within the first end of the interior passage;   a turbine positioned within the second end of the interior passage; and   a combustor positioned within the interior passage between the compressor and the turbine, the combustor extending along a central axis and comprising:   an outer tube having an outer surface and an inner surface defining a passage;   an inner tube positioned within the passage of the outer tube and having an outer surface and an inner surface defining an interior, wherein a fluid passage is defined between the outer surface of the inner tube and the inner surface of the outer tube, the fluid passage being supplied with a mixture of air and combustible fuel, the inner tube and the outer tube having fluid directing structure for causing the mixture of air and combustible fuel within the fluid passage to rotate radially about the central axis.   
     
     
         2 . A combustor for a jet engine, said jet engine having a compressor portion and a turbine portion, the combustor comprising:
 a) an outer tube having a central axis, said outer tube extending longitudinally and positioned to receive air discharged by said compressor portion and said outer tube having an outer surface and an inner surface;   b) an inner tube positioned within said outer tube, said inner tube having an outer surface spaced from said inner surface of said outer tube, thereby defining a combustion chamber passage therebetween;   c) said outer tube including fluid directing structure for communicating at least some of the air discharged by said compressor portion into said combustion chamber passage, said air being directed in a direction offset from said central axis, thereby causing rotation of said air about said central axis;   d) at least one fuel supply member for supplying a fuel to said combustion chamber passage in order to form a rotating fuel air mixture in said combustion chamber passage.   
     
     
         3 . The combustor of  claim 2  wherein said inner tube includes associated fluid directing structure for communicating air discharged by said compressor portion to said combustion chamber passage, said associated fluid directing structure directing said air in a direction that is offset from said central axis. 
     
     
         4 . The combustor of  claim 1  wherein said fuel member communicates with said combustion chamber passage and directly supplies fuel to said combustion chamber passage where it is mixed with said compressor air to form a rotating combustible fuel/air mixture. 
     
     
         5 . The combustor of  claim 2  wherein said fuel member premixes said fuel with some compressor air and then supplies said premixed fuel and air to said combustion chamber passage where it is mixed with the rotating compressor air in said combustion chamber passage. 
     
     
         6 . The apparatus of  claim 2  wherein said fuel member discharges fuel into a stream of air discharged by said compressor and flowing towards said outer tube, said fluid directing structure of said outer tube communicating both fuel and compressor air to said combustion chamber passage. 
     
     
         7 . The apparatus of  claim 1  wherein an axis of said inner tube and said central axis of said outer tube are coincident. 
     
     
         8 . The apparatus of  claim 7  wherein said axes of said inner and outer tubes are also coincident with a rotational axis of said compressor portion. 
     
     
         9 . A combustor for a jet engine, said jet engine having a compressor portion and a turbine portion, the combustor comprising:
 a) a tube having a central axis, the tube being located intermediate said compressor portion and said turbine portion, said tube having an outer surface and an inner surface;   b) fluid directing structure formed on said tube including passages extending from said outer surface to said inner surface;   c) said inner surface of said tube defining a combustion chamber;   d) a passage communicating air discharged by said compressor portion with said outer surface of said tube for delivering compressor air to said combustion chamber through said fluid directing structure, said fluid directing structure directing said compressor air at an angle offset from said central axis, thereby causing rotation of said compressor air in said combustion chamber;   e) a fuel member for supplying fuel to said combustion chamber.   
     
     
         10 . The apparatus of  claim 9  wherein a spaced apart continuous wall surrounds said tube, thereby defining at least a portion of said passage for communicating air to said outer surface of said tube. 
     
     
         11 . The apparatus of  claim 10  wherein said jet engine includes a plurality of said combustors spatially arranged around an axis of rotation defined by said compressor portion. 
     
     
         12 . The apparatus of  claim 2  wherein said rotating fuel air mixture is substantially completely combusted in said combustion chamber passage. 
     
     
         13 . The combustor of  claim 2 , wherein the fluid directing structure includes a plurality of openings and a guide associated with each opening, the guides being angled relative to the tube surface for radially rotating the mixture about the central axis. 
     
     
         14 . The fuel burner of  claim 13 , wherein the guides are arranged in a series of rows that extends around the periphery of the outer tube. 
     
     
         15 . The combustor of  claim 2 , wherein the fluid directing structure includes a series of steps formed into the outer tube, the steps including openings for directing the air into the combustion chamber passage to rotate the mixture radially about the central axis. 
     
     
         16 . The combustor of  claim 15 , wherein each step has an L-shape including a first member and a second member including the openings for directing the air such that the openings of one step direct the air across the adjoining step to impart rotation to the mixture. 
     
     
         17 . The combustor of  claim 2 , wherein the fluid directing structure includes a plurality of openings that each extend from the outer surface of the outer tube to the inner surface; each opening extending through the outer tube at an angle relative to an axis extending normal to the outer surface of the inner tube and through the central axis. 
     
     
         18 . The combustor of  claim 17 , wherein the outer tube includes a plurality of second openings that each extend from the outer surface of the outer tube to the inner surface in a direction extending to the central axis. 
     
     
         19 . The combustor of  claim 2 , wherein the outer tube is formed as a series of overlapping arcuate plates that define the fluid directing structure, each plate having a corrugated profile having a series of passages through which the air is directed into the combustion chamber passage. 
     
     
         20 . The combustor of  claim 19 , wherein the corrugated profile includes a plurality of alternating peaks and valleys. 
     
     
         21 . The combustor of  claim 20 , wherein the overlapping plates are longitudinally and radially offset from one another such that the peaks of one plate are positioned between the peaks of adjacent plates. 
     
     
         22 . The combustor of  claim 19 , wherein each plate directs the air in a direction that extends substantially parallel to the adjoining plate to impart rotation to the mixture. 
     
     
         23 . The combustor of  claim 3 , wherein the inner tube includes a first that communicates with air discharged by said compressor portion and a second end having an end wall for closing the second end of the inner tube in a gas-tight manner, such that said associated fluid directing structure provides the only fluid path to said combustion chamber passage for said air received by said inner tube from said compressor portion. 
     
     
         24 . The combustor of  claim 2 , wherein the rotating mixture is radially layered within the combustion chamber passage. 
     
     
         25 . A method for combusting fuel in a jet engine having compressor and turbine portions, comprising the steps of:
 a) providing a tube having an outer surface communicating with air discharged by said compressor portion and an inner surface at least partially defining a combustion chamber;   b) providing fluid directing structure between said inner and outer surfaces for communicating said compressor air from said outer surface to said combustion chamber, at an angle offset with respect to a central axis of said tube, such that said air is caused to rotate within said combustion chamber;   c) supplying fuel to said combustion chamber to thereby provide a swirling fuel/air mixture;   d) at least partially combusting said fuel air mixture in said combustion chamber;   e) supplying said combusted fuel/air mixture to said turbine portion.   
     
     
         26 . The method of  claim 25  further comprising the step of providing an inner tube within said outer tube such that said combustion chamber is defined between an outer surface of said inner tube and an inner surface of said outer tube. 
     
     
         27 . The method of  claim 26  further comprising the step of directing compressor air from an inner surface of said inner tube to an outer surface of said inner tube through associated fluid directing structure that imparts rotation to said compressor air as it travels into said combustion chamber.