Abstract:
An aircraft includes a fuselage including a propulsion system supported within an aft portion. A thrust reverser is mounted proximate to the propulsion system for directing thrust in a direction to slow the aircraft. The thrust reverser directs thrust at an angle relative to a vertical plane to reduce interference on control surfaces and reduce generation of underbody lift.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/725,106 filed on Nov. 12, 2012. 
     
    
     BACKGROUND 
       [0002]    A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. 
         [0003]    Typically, the gas turbine engine is supported under an aircraft wing on either side of the fuselage. However, such under-wing installations may not be compatible with unique aircraft configurations. Accordingly, different mounting locations for the engines such as at the rear of the fuselage are being considered. Different mountings locations present different challenges and require alternate engine configurations. 
         [0004]    A thrust reverser is utilized once an aircraft has landed, and creates a reverse thrust force to aid in slowing the aircraft. Typical thrust reversers and nozzles are components of the engine nacelle surrounding an under-wing mounted engine. Engines mounted within an aircraft fuselage do not include the same nacelle structures and therefore conventional thrust reversing devices may not be compatible. 
         [0005]    Alternate aircraft architectures may require alternate mounting locations of the gas turbine engines to enable specific wing and fuselage configurations. However, conventional gas turbine engine configurations have been developed to operate with conventional aircraft architectures. 
         [0006]    Accordingly, alternate gas turbine engine configurations may be required and developed to enable implementation of favorable aspects of alternate engine architectures. 
       SUMMARY 
       [0007]    A propulsion system according to an exemplary embodiment of this disclosure, among other possible things includes first and second propulsors mounted at an aft portion of a fuselage, and first and second thrust reversers mounted proximate to corresponding first and second propulsors. Each of the first and second thrust reversers include respective thrust reverser doors, the thrust reverser doors rotatable to a deployed position such that longitudinal centerlines along the thrust reverser doors converge below the thrust reversers thereby reducing lift producible by redirected thrust. 
         [0008]    In a further embodiment of the foregoing propulsion system, the thrust reverser doors include an upper door and a lower door pivotally mounted for movement between a stowed position and the deployed position. 
         [0009]    In a further embodiment of any of the foregoing propulsion systems, the upper door and the lower door are pivotally mounted for movement along the longitudinal centerline that is angled relative to the vertical plane. 
         [0010]    In a further embodiment of any of the foregoing propulsion systems, includes a first engine core driving a first fan and a first bypass passage disposed along a first propulsor axis and a second engine core driving a second fan and a second bypass passage disposed along a second propulsor axis. 
         [0011]    In a further embodiment of any of the foregoing propulsion systems, the first and second thrust reversers includes corresponding first and second upper doors and first and second lower doors that are pivotally mounted for movement between a stowed position and the deployed position. 
         [0012]    In a further embodiment of any of the foregoing propulsion systems, the first and second upper doors and the first and second lower doors close on a centerline of corresponding ones of the first and second bypass passages to capture both a bypass flow stream and a core flow stream. 
         [0013]    An aircraft according to an exemplary embodiment of this disclosure, among other possible things includes a fuselage including an aft portion, a propulsion system supported within the aft portion of the fuselage, and a thrust reverser mounted in the aft portion of the fuselage proximate to the propulsion system for directing thrust in a direction to slow the aircraft. The thrust reverser directs thrust at an angle relative to a vertical plane. 
         [0014]    In a further embodiment of the foregoing aircraft, the propulsion system includes a first engine core driving a first fan within a first bypass passage disposed about a first propulsor axis and a second engine core driving a second fan within a second bypass passage disposed about a second propulsor axis and the thrust reverser inlcudes a first and second thrust reversers each directing thrust at an angle relative to the vertical plane. 
         [0015]    In a further embodiment of any of the foregoing aircrafts, the first and second thrust reversers are angled away from each other such that airflow directed above the first and second thrust reversers flows away from each other and thrust directed below the first and second thrust reversers combines to reduce excess lift. 
         [0016]    In a further embodiment of any of the foregoing aircrafts, the first and second thrust reversers include corresponding first and second upper doors and first and second lower doors that are pivotally mounted for movement between a stowed position and a deployed position. 
         [0017]    In a further embodiment of any of the foregoing aircrafts, the first and second doors and the first and second lower doors close on a corresponding one of the first propulsor axis and the second propulsor axis to capture both a bypass flow stream and a core flow stream. 
         [0018]    In a further embodiment of any of the foregoing aircrafts, the aircraft includes a vertical stabilizer extending upward from the aft portion of the fuselage and the first and second thrust reversers direct thrust away from the vertical stabilizer. 
         [0019]    In a further embodiment of any of the foregoing aircrafts, the vertical stabilizer is disposed between the first and second bypass passages. 
         [0020]    In a further embodiment of any of the foregoing aircrafts, the aircraft includes a horizontal stabilizer supported on the vertical stabilizer. 
         [0021]    Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
         [0022]    These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  schematically shows an example aircraft with a propulsion system mounted within a fuselage. 
           [0024]      FIG. 2  is a schematic view of an example reverse flow gas turbine engine. 
           [0025]      FIG. 3  is a schematic view of view of an example thrust reverser in a stowed position. 
           [0026]      FIG. 4  is a schematic view of the example thrust reverser in a deployed position. 
           [0027]      FIG. 5  is a rear view of the thrust reverser in the deployed position. 
           [0028]      FIG. 6  is a rear view of the example thrust reverser in a stowed position. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    Referring to the  FIGS. 1 and 2  an aircraft  10  includes a fuselage  12  having wings  16  and a tail  14 . A propulsion system  18  is mounted in aft end  15  of the fuselage  12 . The propulsion system  18  includes first and second engine cores, which are reverse core gas turbine engines,  20   a - b  that drive corresponding first and second propulsors, including fan sections  22   a - b.  The first and second fan sections  22   a - b  provide the propulsive thrust through corresponding first and second bypass passages  36   a - b.    
         [0030]    Each of the fan sections  22   a - b  are disposed about corresponding first and second propulsor axis A 1  and A 2 . The first and second engine cores  20   a - b  is disposed about a corresponding first and second engine axis B 1  and B 2 . That is the first engine core  20   a  is disposed about the first engine axis B 1  and drives the first propulsor about the first propulsor axis A 1 . The second engine core  20   b  is disposed about the second engine axis B 2  and drives the second fan section  20   b  about the second propulsor axis A 2 . 
         [0031]    The example engine cores  20   a - b  are gas generators that include a compressor  24 , a combustor  26  and a turbine  28 . Air is drawn in through inlets  32   a - b  to the compressor  24  is compressed and communicated to a combustor  26 . In the combustor  26 , air is mixed with fuel and ignited to generate an exhaust gas stream that expands through the turbine  28  where energy is extracted and utilized to drive the compressor  24  and corresponding fan  22   a - b.  In this example the engine cores  20   a - b  drive the corresponding fan  22   a - b  through a geared architecture  30   a - b  that is part of the propulsor. 
         [0032]    In the disclosed example, each of the first and second propulsors  22   a - b  is mounted substantially parallel to each other about respective propulsor axes A 1 , A 2 . The first and second engine axes B 1 , B 2  are disposed at an angle  34  relative to the corresponding propulsor axis A 1 , A 2 . The engine cores  20   a - b  are also angled away from each other at an angle  38 . 
         [0033]    Referring to  FIGS. 3 and 4 , the aircraft includes a thrust reverser for directing thrust to slow the aircraft  10  upon landing. The disclosed thrust reverser includes a first thrust reverser  40   a  and a second thrust reverser  40   b  for corresponding bypass passages  36   a - b.  The first and second thrust reversers  40   a - b  include corresponding first and second upper doors  42   a,    42   b  and first and second lower doors  44   a,    44   b.    
         [0034]    The upper and lower doors  42   a - b,    44   a - b  are movable between a stowed position ( FIG. 3 ) and a deployed position ( FIG. 4 ). Movement of the upper and lower doors  42   a - b,    44   a - b,  is facilitated by pivots  48  that support rotation between stowed and deployed positions. An actuator  46  is provided to move the upper and lower doors  42   a - b,    44   a - b  between the stowed and deployed positions. 
         [0035]    In the stowed position, thrust flows unimpeded through the bypass passages  36   a - b.  In the deployed position, thrust is directed upwardly as indicated at  52  and downwardly as indicated at  56  about the propulsor axes A 1 , A 2 . The upward and downward directed thrust  52 ,  54  slows the aircraft  10  during landing. In some aircraft  10  architectures, the downward directed thrust  54  can generate undesired lift by directing thrust under the aircraft fuselage  12  or other surface. As appreciated, thrust that generates lift, or interferes with desired aircraft aerodynamic performance is undesirable. 
         [0036]    Referring to  FIGS. 5 and 6 , the example thrust reversers  40   a - b  are angled relative to a vertical plane  50  to reduce and/or eliminate the generation of lift on the aircraft  10 . The first and second thrust reversers  40   a - b  are circumferentially oriented, or clocked about the corresponding propulsor axes A 1 , A 2  to direct upward thrust  52  away from the vertical plane  50 . 
         [0037]    In this example the first and second thrust reversers  40   a - b  close about respective centerlines  58   a,    58   b  that are angled away from each other above the axes A 1 , A 2 . The angle  54  between the centerlines  58   a,    58   b  enables direction of upward thrust  52  away from the vertical plane  50  and vertical stabilizer  19 . 
         [0038]    The angle  54  results in the centerlines  58   a - b  intersecting at a point below the axes A 1 , A 2 . Accordingly, downward thrust  56  combine below the axes A 1 , A 2  and the aircraft fuselage  12  to effectively cancel any resulting lift forces generated on the fuselage  12 . 
         [0039]    Accordingly, the disclosed thrust reversers  40   a - b  are angled to avoid thrust impingement on the tail  14  and also combine downward thrust to substantially reduce any generation of lift on the aircraft. 
         [0040]    Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure.