Abstract:
The present disclosure concerns a nacelle for an aircraft engine, which includes a thrust reverser cowling that is slidably mounted between a direct jet position, and a reversed jet position in which the cowling opens a passage in the nacelle and uncovers a deflection device, and at least one actuator for moving the cowling. The nozzle section of the cowling delimits at least one opening that is combined with a leakage door, the leakage door being movably mounted on the cowling between a closed position in which the door engages with the associated opening to counteract the flow of air through said opening, and an open escape position in which the door is retracted to allow a portion of the air flow to flow through said opening.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/FR2014/052595, filed on Oct. 13, 2014, which claims the benefit of FR 13/59896, filed on Oct. 11, 2013. The disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a nacelle for an aircraft engine with a variable section nozzle. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0004]    As is known, an aircraft engine nacelle allows conveying outside air toward the engine, of the turbojet engine type for example, and providing the ejection of air at high velocity so as to provide thrust. 
         [0005]    In bypass turbojet engines, the air flow mixed by the fan is divided, downstream thereof, into a primary flow (also said “hot”) which enters inside the core of the turbojet engine in order to undergo several compressions and an expansion, and a secondary flow (also said “cold”), which circulates inside a substantially annular flow path, defined on the one hand by a fairing of the engine (fixed internal structure, also called “IFS”), and on the other hand by the thickness of the nacelle. 
         [0006]    The cold air flow, coming out downstream of the nacelle via an output nozzle defined by the downstream edge of the nacelle, provides most of the thrust. 
         [0007]    Moreover, as is known, the nacelle incorporates very frequently thrust reversal means, allowing directing a portion of the secondary air flow upstream of the nacelle during landing, thereby actively contributing to the braking of the aircraft. 
         [0008]    These thrust reversal means are often of the cascade type, that is to say that they include a series of vanes arranged downstream of the fan casing, at the periphery of the flow path of cold flow. These vanes can be uncovered on request by a thrust reverser cowl slidingly mounted on the structure of the nacelle. 
         [0009]    In addition to a thrust reversal function, a movable thrust reverser cowl belongs to the rear section of the nacelle and may have a portion forming an ejection nozzle. 
         [0010]    The section of the ejection nozzle of the cowl can be adjusted depending on the different phases of flights, which may in particular include take-off, climb, cruise, descent and landing in order to always keep a desired nozzle section depending on the turbojet engine speed. The nozzle will then be called variable section nozzle. 
         [0011]    Such a variable section nozzle is associated with an actuating system allowing this section variation. 
         [0012]    There are several solutions to make a variable section nozzle. 
         [0013]    In particular, there is known a nacelle described and represented in the document FR-2622929, which is equipped with a movable thrust reverser cowl which has an upstream section intended to cover the cascade vanes, and a downstream section forming a variable section nozzle. 
         [0014]    According to this document, the downstream section of the cowl has a generally annular shape, the downstream section being slidingly mounted axially on the upstream section to clear a leakage passage between the downstream section and the upstream section of the cowl. 
         [0015]    This leakage passage allows a portion of the air flow flowing in the secondary flow path to be ejected, which amounts to expanding the section of the nozzle formed by the cowl. 
         [0016]    Although this type of nacelle allows effectively varying the section of the nozzle, it has some disadvantages. 
         [0017]    Indeed, the mechanical connection between the downstream movable annular portion and the upstream portion of the cowl constitutes a mechanical weakening of the nacelle. 
         [0018]    In addition to weakening the thrust reverser cowl, this mechanical connection may also generate vibrations of the downstream annular portion of the cowl during the operation of the engine. 
       SUMMARY 
       [0019]    The present disclosure provides a nacelle for an aircraft engine, of the type comprising:
       a thrust reverser cowl including a covering upstream section and a nozzle downstream section, the cowl being slidingly mounted along a direction generally parallel to the longitudinal axis of the nacelle, between a direct jet position in which the cowl covers a device for deflecting the air flow, and a reverse jet position in which the cowl opens a passage in the nacelle and uncovers the deflecting device, and   a device for driving in displacement the cowl including at least one actuator,       
 
         [0022]    characterized in that the nozzle section of the cowl delimits at least one opening which is associated with a leakage door, the leakage door being movably mounted on the cowl between a closed position in which the door cooperates with the associated opening to oppose the flow of the air flow through said opening, and a leakage open position in which the door is retracted to allow the flow of a portion of the air flow through said opening. 
         [0023]    Such a design allows making a one-piece movable thrust reverser cowl, the covering upstream section of the deflecting device and the nozzle downstream section being integrally made, in order to enhance the mechanical strength of the cowl. 
         [0024]    According to another feature, the nacelle is equipped with a device for locking the leakage door on the movable cowl, the locking device being designed to adopt an unlocked state in which the leakage door is detached from the cowl, and a locked state in which the leakage door is locked on the cowl, so that the leakage door and the cowl are adapted to be simultaneously driven in displacement by the actuator. 
         [0025]    The locking device allows driving in displacement the cowl and/or the door selectively or jointly, by the same actuator. 
         [0026]    According to a first variant of the present disclosure, the leakage door is slidingly mounted between its closed position and its open position, along a direction generally parallel to the axis of the nacelle. 
         [0027]    This first variant is associated with a flow deflecting device with movable cascade vanes, the latter generally offering more space to allow the sliding travel of the leakage door. 
         [0028]    According to a second form of the present disclosure, the leakage door is pivotally mounted between its closed position and its open position about an axis substantially perpendicular to the axis of the nacelle. 
         [0029]    This second variant is particularly adapted to a flow deflecting device for with fixed cascade vanes, the latter offering a limited space downstream of the cascade vane for housing the leakage door. 
         [0030]    According to this second variant, the leakage door includes:
       an inner skin which is pivotally mounted on a fixed portion of the nacelle,   an outer skin which extends opposite the inner skin and which is pivotally mounted on a fixed portion of the nacelle, the outer skin having an opening angle smaller than that of the inner skin in order to limit the aerodynamic disturbances outside the nacelle when the leakage door occupies its open position.       
 
         [0033]    According to another aspect, the door has an outer face which is designed to provide the external aerodynamic continuity of the fairing of the nacelle, and an inner face which is designed to provide the internal aerodynamic continuity of the nacelle, when the door occupies its closed position. 
         [0034]    In addition, the nacelle includes sealing system, which is designed to oppose the flow of air through the opening when the leakage door occupies its closed position. 
         [0035]    By avoiding air leakages, the sealing system ensures improved operation and efficiency of the nacelle and of the associated engine. 
         [0036]    In order to enhance the mechanical strength of the cowl, the covering upstream section and the nozzle downstream section of the cowl are integrally made in one form of the present disclosure. 
         [0037]    In addition, the actuator includes an upstream body secured to a fixed portion of the nacelle and a downstream actuating rod which is slidingly mounted in the associated body along an axis generally parallel to the axis of the nacelle and which is connected on the leakage door to drive the leakage door in displacement. 
         [0038]    According to one form of the present disclosure, the cowl delimits a plurality of openings which are distributed circularly around the longitudinal axis of the nacelle and which are each associated to a movable leakage door. 
         [0039]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0040]    In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
           [0041]      FIG. 1  is an overall perspective view, which illustrates an aircraft nacelle including a thrust reverser cowl delimiting four leakage openings, according to the present disclosure; 
           [0042]      FIG. 2  is a schematic longitudinal sectional view, which illustrates the thrust reverser cowl of  FIG. 1  in its direct jet position and the leakage door in its closed position, according to a first form of the present disclosure; 
           [0043]      FIG. 3  is a schematic view similar to that of  FIG. 2 , which illustrates the thrust reverser cowl of  FIG. 1  in its direct jet position and the leakage door in its open position, according to the first form of the present disclosure; 
           [0044]      FIG. 4  is a schematic view similar to that of  FIG. 2 , which illustrates the thrust reverser cowl of  FIG. 1  in its reverse jet position and the leakage door in its open position, according to the first form of the present disclosure; 
           [0045]      FIG. 5  is a schematic longitudinal sectional detail view, which illustrates a sealing system of the leakage door according to the first form of the present disclosure; 
           [0046]      FIG. 6  is a schematic longitudinal sectional view, which illustrates the thrust reverser cowl of  FIG. 1  in its direct jet position and the leakage door in its closed position, according to a second form of the present disclosure; 
           [0047]      FIG. 7  is a schematic view similar to that of  FIG. 6 , which illustrates the thrust reverser cowl of  FIG. 1  in its direct jet position and the leakage door in its open position, according to the second form of the present disclosure; 
           [0048]      FIG. 8  is a schematic view similar to that of  FIG. 6 , which illustrates the thrust reverser cowl of  FIG. 1  in its reverse jet position and the leakage door in its open position, according to the second form of the present disclosure; 
           [0049]      FIG. 9  is a schematic longitudinal sectional detail view along the axis  9 - 9  of  FIG. 1 , which illustrates the hinge of the leakage door represented in its closed position, according to the second form of the present disclosure; 
           [0050]      FIG. 10  is a schematic longitudinal sectional detail view along the axis  10 - 10  of  FIG. 1 , which illustrates the hinge of the leakage door represented in its closed position, according to the second form of the present disclosure; 
           [0051]      FIG. 11  is a schematic longitudinal sectional detail view along the axis  9 - 9  of  FIG. 1 , which illustrates the hinge of the leakage door represented in its open position, according to the second form of the present disclosure; 
           [0052]      FIG. 12  is a schematic longitudinal sectional detail view along the axis  10 - 10  of  FIG. 1 , which illustrates the hinge of the leakage door represented in its open position, according to the second form of the present disclosure; 
           [0053]      FIG. 13  is a schematic longitudinal sectional detail view, which illustrates a sealing system of the leakage door according to the second form of the present disclosure; 
           [0054]      FIG. 14  is a schematic cross-sectional view, which illustrates a side sealing system of the leakage door according to the second form of the present disclosure; 
           [0055]      FIG. 15  is a schematic view similar to that of  FIG. 14 , which illustrates a first variant of the side sealing system of the leakage door according to the second form of the present disclosure; and 
           [0056]      FIG. 16  is a schematic view similar to that of  FIG. 14 , which illustrates a second variant of the side sealing system of the leakage door according to the second form of the present disclosure. 
       
    
    
       [0057]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
       DETAILED DESCRIPTION 
       [0058]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
         [0059]    In the description and the claims, to clarify the description and the claims, the terminology longitudinal, vertical and transverse will be adopted with no limitation with reference to the trihedron L, V, T indicated in the figures, whose axis L is parallel to the axis A of the nacelle. 
         [0060]    Note that in the present disclosure, the terms “upstream” and “downstream” should be understood in relation to the circulation of the air flow inside the propulsion unit formed by the nacelle and the turbojet engine, that is to say from the left to the right with reference to  FIGS. 1 to 13 . 
         [0061]    Similarly, the expressions “front” and “rear” will be used with no limitation respectively with reference to the left portion and right portion of  FIGS. 1 to 13 . 
         [0062]    In  FIG. 1 , there is represented a nacelle  10  for an aircraft engine of the turbojet engine type (not represented), the nacelle  10  extending along a longitudinal axis A. 
         [0063]    The nacelle  10  is intended to be suspended from an engine pylon  5  (not represented) via a fixation islet (not represented) forming a connection interface. 
         [0064]    The nacelle  10  extends from the front to the back from an upstream air inlet section  12 , a midsection  14  and a downstream section  16  equipped with a thrust reverser device  18 . 
         [0065]    The thrust reverser device  18  comprises a substantially peripheral thrust reverser cowl  20  and a set of cascade vanes  22  (one of which is partially represented in  FIG. 2 ). 
         [0066]    The cascade vanes  22  are slidingly mounted along the axis A of the nacelle  10 , between a retracted position represented in  FIGS. 2 and 3 , in which the vanes  22  are arranged at least partially in the thickness of the midsection  14  of the nacelle  10 , and a deployed position represented in  FIG. 4 , in which the vanes  22  extend downstream of the midsection  14 . 
         [0067]    As can be seen in  FIG. 2 , the thrust reverser cowl  20  is arranged around an annular fixed inner structure  24  forming a fairing of the turbojet engine, to delimit a flow path  26  of a secondary air flow. 
         [0068]    Furthermore, the cowl  20  includes an upstream covering section  28  of the cascade vanes  22  and a nozzle downstream section  30 . 
         [0069]    In addition, thrust reverser flaps  32  are hingedly mounted on the cowl  20  each via a connecting rod  34  pivotally mounted on the fairing fixed inner structure  24  of the turbojet engine. 
         [0070]    The cowl  20  is slidingly mounted along a direction generally parallel to the axis A of the nacelle  10 , between a direct jet position represented in  FIGS. 1 to 3 , in which the thrust reversal flaps  32  are arranged in the extension the thrust reversal cowl  20  to allow the free circulation of the air flow in the flow path  26  and the air flow cascade vanes  22  are covered and, a reverse jet position represented in  FIG. 4 , in which the cowl  20  is slid downstream of the cascade vanes  22 , resulting in pivoting of the thrust reversal flaps  32  through the flow path  26  of the secondary air flow, causing the deflection of the air flow through the vanes  22 , outward and upstream of the nacelle  10 . 
         [0071]    In addition, the cowl  20  is designed to adopt a further maintenance position (not represented), in which the cowl  20  is moved fully rearward to allow access to the interior of the nacelle  10 . 
         [0072]    According to another aspect, the nozzle section  30  of the cowl  20  delimits four openings  36  that are each associated with a leakage door  38 . 
         [0073]    The four openings  36  are arranged in a circle around the axis A of the nacelle  10 , at the periphery of the nacelle, and they are each shaped in the form of a slot open radially outward of the nacelle  10 , delimiting a passage between the flow path  26  of the air flow and the outside of the nacelle  10 . 
         [0074]    The openings  36  are separated into pairs by a rigid connection portion  40  of the cowl  20 , represented in  FIG. 1 . 
         [0075]    In order not to encumber the description, only one set constituted by an opening  36  and an associated leakage door  38  is described in detail hereinafter, the openings  36  and the associated doors  38  being all similar. 
         [0076]      FIGS. 2 to 5  represent the cowl  20  of the nacelle  10  according to a first form  20  of the present disclosure. 
         [0077]    According to this first form, the leakage door  38  is slidingly mounted on the cowl  20  longitudinally along the axis A of the nacelle  10 , between a closed position represented in  FIG. 2 , in which the door  38  cooperates with the associated opening  36  to oppose the flow of the air flow through the opening  36 , and an open leakage position represented in  FIGS. 3 and 4 , in which the door  38  is retracted to allow the flow of a portion of the air flow through the opening  36 . 
         [0078]    The air flow is represented by arrows in  FIGS. 2 to 4 . 
         [0079]    Referring to  FIG. 2 , the leakage door  38  is delimited by an outer face  42  which is designed to provide external aerodynamic continuity of the fairing of the nacelle  10 , and an inner face  44  which is designed to ensure the internal aerodynamic continuity of the nacelle  10 , in order not to disturb the flow of the air flow through the flow path  26 , when the door  38  occupies its closed position. 
         [0080]    As can be seen in  FIGS. 3 and 4 , the leakage door  38  is generally arranged in the extension of the vane  22 , downstream of the vane  22 . 
         [0081]    More specifically, the leakage door  38  is radially interposed between the flap  32  and the outer fairing of the cowl  20 , when the door  38  occupies its open position and the cowl  20  occupies its direct jet position, with reference to  FIG. 3 . 
         [0082]    In addition, according to  FIG. 5 , the nacelle  10  includes a first O-ring seal  46  and a second O-ring seal  48  forming one variation of a sealing system according to the present disclosure, which are designed to oppose the flow of air through the opening  36  when the leakage door  38  occupies its closed position. 
         [0083]    The first seal  46  is carried by a corner piece  50  which is arranged at an upstream end of the leakage door  38 , facing a transverse edge  52  formed by the cowl  20 , the first seal  46  being adapted to cooperate with the transverse edge  52  of the cowl  20  when the leakage door  38  is closed. 
         [0084]    Similarly, the second seal  48  is carried by a corner piece  54  which is arranged at the upstream end of the leakage door  38 , facing an outer face  56  of the reversal flap  32 , the second seal  48  being adapted to cooperate with the outer face  56  of the flap  32  when the leakage door  38  is closed and the cowl  20  is in the direct jet position. 
         [0085]    According to another aspect, the leakage door  38  is driven in displacement by an actuator  58  of the cylinder type which includes an upstream body  60  (partially represented) secured to a fixed portion of the nacelle  10  and a downstream actuating rod  62 . 
         [0086]    The actuating rod  62  of the actuator  58  is slidingly mounted in the associated body  60  longitudinally along an axis generally parallel to the axis A of the nacelle  10 . 
         [0087]    In addition, the rod  62  has a downstream free end  64  which is connected on the leakage door  38  to drive the door  38  in displacement. 
         [0088]    In a complementary manner, the nacelle  10  is equipped with a locking device “L” for locking the leakage door  38  on the movable cowl  20 . 
         [0089]    The locking device L is designed to adopt an unlocked state in which the leakage door  38  is detached from the cowl  20  and is capable to be driven in displacement separately, directly by the associated actuator  58 , and a locked state in which the leakage door  38  is locked on the cowl  20  so that the leakage door  38  and the cowl  20  are adapted to be simultaneously driven in displacement by the actuator  58 . 
         [0090]    The locking device L is of a type such as a claw or hook lock, and it is associated with any known control type, whether hydraulic, electric or pneumatic, linked to the control system of the nacelle  10  also of a known type. 
         [0091]    An example of the different steps of locking and unlocking the leakage door  38  and the cowl  20  is represented in  FIGS. 2 to 5 . 
         [0092]    In  FIG. 2 , the leakage door  38  is closed and the cowl  20  occupies its direct flow position. 
         [0093]    In  FIG. 3 , the leakage door  38  is driven in translation rearward by the actuator  58 , from its closed position, to its open position, thereby causing an increase of the nozzle section  30  formed by the cowl  20 . 
         [0094]    To this end, the locking device L occupies an unlocked state to detach the leakage door  38  and the cowl  20 . 
         [0095]    Conversely, referring to  FIG. 4 , the locking device L occupies a locked state to secure the cowl  20  and the leakage door  38  in displacement, while the set formed by the cowl  20  and the leakage door  38  is driven rearward by the actuator  58  until the cowl  20  occupies its indirect jet position, in order to uncover the cascade vane  22  and pivotally drive the flap  32 . 
         [0096]      FIGS. 6 to 16  represent the cowl  20  of the nacelle  10  according to a second form of the present disclosure. 
         [0097]    According to this second form, the leakage door  38  is pivotally mounted on the cowl  20 , between a closed position represented in  FIGS. 6, 9 and 10 , in which the door  38  cooperates with the associated opening  36  to oppose the flow of the air flow through the opening  36 , and a leakage open position represented in  FIGS. 7, 8, 11 and 12  in which the leakage door  38  is retracted to allow the flow of a portion of the air flow through the opening  36 . 
         [0098]    The air flow is represented by arrows in  FIGS. 6 to 8 . 
         [0099]    According to the second form of the present disclosure, as can be seen in detail in  FIGS. 9 to 12 , the leakage door  38  includes an inner skin  66 , an outer skin  68  and a slide  70  which slidingly connects the inner skin  66  and the outer skin  68  together. 
         [0100]    The inner skin  66  and the outer skin  68  are pivotally mounted on the cowl  20  about an axis B and an axis C, respectively, the axes B and C being perpendicular to the axis A of the nacelle  10  and shifted from each other, the pivot axis B of the inner skin  66  being radially closer to the central axis A of the nacelle  10  than the pivot axis C of the outer skin  68 , as can be seen in  FIG. 10 . 
         [0101]    Furthermore, according to  FIG. 9 , the inner skin  66  has an upstream portion  72  which is pivotally mounted on the actuating rod  62  of the actuator  58 . 
         [0102]    In addition, according to  FIG. 10 , the inner skin  66  includes a guide rail  74  which extends toward the outer skin  68  and which is slidingly mounted in the slide  70  provided for this purpose. 
         [0103]    In a complementary manner, the slide  70  is equipped with a pivot head  76  which is pivotally mounted on the outer skin  68 , so that the slide  70  is pivotally hinged on the outer skin  68  about an axis D perpendicular to the axis A of the nacelle  10 , and parallel to the pivot axes B and C of the inner skin  66  and outer skin  68 , respectively. 
         [0104]    The pivoting drive of the leakage door  38  according to the second form, from its open position to its closed position, is described below. 
         [0105]    The rod  62  of the actuator  58  is driven forward, or upstream, of the nacelle  10  so that the inner skin  66  pivots about its pivot axis B. 
         [0106]    Simultaneously, as can be seen in  FIG. 12 , the guide rail  74  of the inner skin  66  slides in the slide  70 , the slide  70  being then driven in displacement substantially radially outward of the nacelle  10 , the slide  70  jointly pivotally driving the outer skin  68  about its pivot axis C. 
         [0107]    Such a mechanism allows the outer skin  68  to have an opening angle smaller than that of the inner skin  66  to limit the overlapping of the outer skin  68  outside the nacelle  10  when the leakage door  38  is in its open position, in order to limit aerodynamic disturbances outside the nacelle  10 . 
         [0108]    According to another aspect, with reference to  FIG. 13 , still according to the second form of the present disclosure, the door  38  is equipped with a first upstream seal  78  and a second downstream seal  80  of the O-ring type, forming a sealing system between the door  38  and the associated opening  36  of the cowl  20 , when the door  38  occupies its closed position. 
         [0109]    To this end, the first upstream seal  78  is interposed between an upstream end portion  82  of the outer skin  68  of the door  38 , and an outer envelope  84  of the cowl  20 . 
         [0110]    Similarly, the second downstream seal  80  is interposed between a downstream portion  86  of the outer skin  68  of the door  38  and the outer envelope  84  of the cowl  20 . 
         [0111]    In a complementary manner, as represented in  FIG. 14 , the leakage door  38  is equipped with a side sealing system between the door  38  and the associated opening  36  of the cowl  20 , in order to inhibit the transverse or side air leakages, that is to say in a direction perpendicular to the axis A of the nacelle  10 , between the door  38  and the associated opening  36 , when the door  38  occupies its closed position. 
         [0112]    The side sealing system in one form includes a first seal  88  which is interposed between a first longitudinal side edge  90  of the door  38  and a complementary first longitudinal side edge  92  of the outer envelope  84  of the cowl  20 . 
         [0113]    In a symmetrical manner, this side sealing system includes a second seal  94  which is interposed between a second longitudinal side edge  96  of the door  38  and a complementary second longitudinal side edge  98  of the outer envelope  84  of the cowl  20 . 
         [0114]    According to a variant of the side sealing system, represented in  FIG. 15 , the door  38  includes a first sealing strip  102  which extends from the first longitudinal side edge  90  of the door  38 , to the first side edge  92  of the outer envelope  84  of the cowl  20 , in order to inhibit the side air leakages between the door  38  and the associated opening  36 . 
         [0115]    In a symmetrical manner, the door  38  includes a second sealing strip  104  which extends from the second longitudinal side edge  96  of the door  38 , to the second side edge  98  of the outer envelope  84  of the cowl  20 . 
         [0116]    Finally, according to another variant of the side sealing system, represented in  FIG. 16 , the first sealing strip  102  is fixed on the first longitudinal side edge  90  of the door  38  and on the first side edge  92  of the outer envelope  84  of the cowl  20 , so that the first sealing strip  102  forms a bib, or a web, to avoid the flow of air on the sides of the door  38 , in order to promote a longitudinal axial flow of air through the opening  36  when the door  38  is open, thereby enhancing the thrust performances of the nacelle  10 . 
         [0117]    To this end, the first sealing strip is made of a resiliently deformable material, such as an elastomer. 
         [0118]    In a symmetrical manner, the second sealing strip  104  is fixed on the second longitudinal side edge  96  of the door  38  and on the second side edge  92  of the outer envelope  84  of the cowl  20 . 
         [0119]    In addition, in order to avoid the flow of air on the sides of the door  38 , rigid side bibs  106  are arranged on each side of the door  38 , as can be seen in  FIGS. 14 to 16 . 
         [0120]    Without limitation, the present disclosure also applies to a nacelle comprising a thrust reverser device  22  with so-called “fixed” cascade vanes. 
         [0121]    Similarly, the present disclosure is not limited to a cowl  20  delimiting four openings  36 , the number of openings may be, for example, six. 
         [0122]    Nonetheless, this type of thrust reverser device with fixed vanes offering a smaller space for housing the leakage doors, it will be in one form associated with the second form of the present disclosure according to which the leakage door  38  is pivotable and uses only a reduced travel space in the cowl  20 .