DEVICE MODELING AN AIRCRAFT PROPULSION ASSEMBLY

Abstract

DEVICE MODELING AN AIRCRAFT PROPULSION ASSEMBLY One aspect of the invention relates to a device 100 modeling an aircraft propulsion assembly configured to carry out mechanical tests comprising a nacelle 101 with a longitudinal axis X surrounding a shroud 102 with a longitudinal axis X, the shroud 102 surrounding the upstream portion of a fixed casing 103 with a shroud with a longitudinal axis X, the shroud 102 and the fixed casing 103 being independent of each other, a primary flow channel 104 being surrounded externally by the fixed casing 103 and a secondary flow channel 107 being formed between the shroud 102 and the nacelle 101, the device being remarkable in that it comprises a deformable sealing shroud 109, the sealing shroud 109 ensuring a seal between the shroud 102 and the fixed casing 103. Figure to be published with the abstract: Figure 3

Description

Title of the invention: DEVICE MODELING AN AIRCRAFT PROPULSION ASSEMBLY TECHNICAL FIELD OF THE INVENTION

[0001] The field of the invention is that of devices modeling an aircraft propulsion unit configured to carry out mechanical tests whose objective is to demonstrate the counter-thrust capacity of a fan as well as the correct supply of a primary channel in reverse condition. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] In a manner known per se, in order to demonstrate the counter-thrust capacity of a fan as well as the correct supply of the primary channel in reverse condition, devices are known which model an aircraft propulsion unit 1 conforming to that illustrated in [Fig.l].

[0003] Such a device 1 extends along a longitudinal axis X oriented from upstream to downstream. Subsequently, the terms “upstream” and “downstream” are defined with respect to the orientation of the longitudinal axis X. The terms “inner” and “outer” are defined in the radial direction with respect to the longitudinal axis X.

[0004] The device 1 comprises a nacelle 2 with a longitudinal axis X surrounding a cover 3 in the form of a shell with a longitudinal axis X. The cover 3 surrounds the upstream part of a fixed casing 4 in the form of a shell with a longitudinal axis X.

[0005] The cover 3 and the fixed casing 4 surround a machine frame 5 embodying a turbojet.

[0006] A primary flow channel 6 is externally surrounded by the internal surface of the fixed casing 4.

[0007] A secondary flow channel 7 is formed between the external surface of the cover 3 and the internal surface of the nacelle 2.

[0008] The device 1 further comprises, upstream, a blower 8 mounted to rotate around the longitudinal axis X to accelerate the flow of internal air from upstream to downstream. This blower 8 is connected to first means 9 for measuring the forces applied to the blower 8.

[0009] Downstream of the blower 8, arranged in the secondary channel 7, are placed flow straightening vanes 10, also designated by the acronym OGV (for Outlet Guide Vanes in English) making it possible to straighten the flow of cold air generated by the blower 8.

[0010] In addition, inlet guide vanes 11, also designated by the acronym IGV (for Inlet Guide Vanes in English) are present in the channel primary 6.

[0011] The flow straightening vanes 10, the inlet guide vanes 11 and the cowl 3 are integral with each other and connected to second means 12 for measuring the mechanical forces applied to these elements.

[0012] It should be noted that in order not to disturb the measurements, the fan 8, the flow straightening vanes 10, the inlet guide vanes 11, the cowl 3 as well as the first and second measuring means 9, 12 must be capable of moving slightly relative to the fixed casing 4.

[0013] As illustrated in [Fig.2], in order to allow relative movements of the aforementioned elements with respect to the fixed casing 4, there is a leakage zone 13 from the primary channel 6 to the secondary channel 7 at the junction between the cowl 3 and the fixed casing 4. This leakage zone 13 influences the results negatively when it is desired to demonstrate the counter-thrust capacity of a fan as well as the good supply of a primary channel in reverse condition. Summary of the invention

[0014] An objective of the invention is to propose a device modeling an aircraft propulsion unit in which relative movements between the cowl and the fixed casing are permitted and in which the leakage zone from the primary channel to the secondary channel is eliminated.

[0015] To this end, the invention thus relates, in its broadest acceptance, to a device modeling an aircraft propulsion unit configured to carry out mechanical tests comprising a nacelle with longitudinal axis X surrounding a shroud-shaped cowl with longitudinal axis X, the cowl surrounding the upstream part of a fixed casing with a shroud-shaped casing with longitudinal axis X, the cowl and the fixed casing being independent of each other, a primary flow channel being surrounded externally by the fixed casing and a secondary flow channel being formed between the cowl and the nacelle.

[0016] The device according to this aspect of the invention is remarkable in that it comprises a deformable sealing ferrule, the sealing ferrule ensuring a seal between the cover and the fixed casing.

[0017] The term “hood and fixed casing independent of each other” means that the hood can make slight movements relative to the fixed casing and vice versa.

[0018] The sealing shroud thus prevents the flow of air from the primary channel to the secondary channel. In addition, being deformable, it also allows the hood to move relative to the fixed casing.

[0019] In addition to the characteristics which have just been mentioned in the preceding paragraph, the device according to the invention may have one or more additional characteristics among the following, considered individually or in all technically possible combinations.

[0020] According to a non-limiting implementation of the invention, the sealing ferrule is arranged between a downstream end of the cover and a downstream end of the fixed casing. In other words, the sealing ferrule forms a junction between the downstream end of the cover and the downstream end of the fixed casing.

[0021] According to a non-limiting implementation of the invention, the sealing ferrule comprises a first part bearing on an external surface of the fixed casing and a second part substantially perpendicular to the first part, the second part bearing on a bearing surface of the cover substantially perpendicular to the external surface of the fixed casing, the first part being integral with the fixed casing and the second part being integral with the cover.

[0022] According to a non-limiting implementation of the invention, the device comprises a blower arranged at the inlet of the primary channel and the secondary channel, the blower being mechanically connected to first means for measuring the forces applied to the blower.

[0023] According to a non-limiting implementation of the invention, the device comprises inlet guide vanes arranged in the primary channel and flow straightening vanes arranged in the secondary channel, the inlet guide vanes, the flow straightening vanes and the cover being mechanically connected to second means for measuring the forces applied to the inlet guide vanes and the flow straightening vanes.

[0024] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures.

[0025] [Fig-1] illustrates, schematically, a device modeling a propulsion unit aircraft according to the prior art.

[0026] [Fig.2] schematically illustrates a leak from the primary channel to the secondary channel secondary in a device modeling an aircraft propulsion assembly according to the prior art.

[0027] [Fig.3] illustrates, schematically, a sectional view of a modeling device an aircraft propulsion assembly configured to perform mechanical tests according to a non-limiting aspect of the invention.

[0028] [Fig.4] illustrates, schematically, an enlargement of a sealing ferrule which is included in the device illustrated in [Fig.3].

[0029] The figures are presented for information purposes only and in no way limit the invention.

[0030] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0031] Figures 1 and 2 have been described in support of the prior art.

[0032] [Fig. 3] illustrates a non-limiting exemplary embodiment of a device 100 modeling an aircraft propulsion assembly according to the invention.

[0033] The device 100 comprises a nacelle 101 with longitudinal axis X surrounding a cover 102 in the form of a shell with longitudinal axis X.

[0034] The cover 102 surrounds the upstream part of a fixed casing 103 in the form of a ferrule with a longitudinal axis X.

[0035] Inside the fixed casing 103 is formed a primary channel 104 for the flow of the streams.

[0036] The external surface 105 of the cover 102 forms the internal surface of a secondary flow channel 107. The internal surface 108 of the nacelle 101 forms the external surface of the secondary channel 107.

[0037] The device 100 also comprises a deformable sealing ferrule 109 ensuring a seal between the cover 102 and the fixed casing 103. According to this embodiment, the sealing ferrule 109 is arranged between a downstream end of the cover 102 and a downstream end of the fixed casing 103. In other words, this sealing ferrule 109 forms a sealed junction between the downstream end of the cover 102 and the downstream end of the fixed casing 103.

[0038] [Fig.4] illustrates an enlargement of this sealing ferrule 109.

[0039] The sealing ferrule 109 comprises a first part 110 bearing on the external surface 106 of the fixed casing 103 and a second part 111 substantially perpendicular to the first part 110.

[0040] The second part 111 bears on a bearing surface 112 of the cover 102 substantially perpendicular to the external surface 106 of the fixed casing 103.

[0041] In other words, the sealing ferrule 109 forms a shouldered ferrule bearing on the cover 102 and the fixed casing 103 and obstructs the leakage zone present in the prior art.

[0042] According to this non-limiting embodiment, the first part 110 and the second part 111 are joined together by a curved surface 113.

[0043] The deformation of the first part 110 with respect to the second part 111 or vice versa is made possible by the small thickness of the sealing ferrule 109. Indeed, the first part 110 is able to pivot with respect to the second part 111 and vice versa.

[0044] In order to improve the sealing between the primary channel 104 and the secondary channel 107, the device 100 comprises a first compression ferrule 114.

[0045] This first compression ferrule 114 is arranged around the first part 110 of the sealing ferrule 109 and compresses this first part 110 against the external surface 106 of the fixed casing 103.

[0046] According to this non-limiting embodiment, the first compression ferrule 114 and the first part 110 of the sealing ferrule 109 are secured to the fixed casing 103 by screws 115. The screw heads 115 bear on the first compression ferrule 114 which distributes the force uniformly around the periphery of the first part 110 of the sealing ferrule 109.

[0047] The device 100 further comprises a second compression ferrule 116. This second compression ferrule 116 compresses the second part 111 of the sealing ferrule 109 onto the bearing surface 112 of the cover 102.

[0048] According to this non-limiting embodiment, the second compression ferrule 116 and the second part 111 of the sealing ferrule 109 are secured to the cover 102 by screws 115. The screw heads 115 bear on the second compression ferrule 116 which distributes the force uniformly around the periphery of the second part 111 of the sealing ferrule 109.

[0049] The device 100 also comprises a blower 117 arranged at the inlet of the primary channel 104 and the secondary channel 107.

[0050] This blower 117 is rotatably mounted around the longitudinal axis X to accelerate the flow of air inside the device 100 from upstream to downstream. This blower 117 is mechanically connected to first measuring means 118 of the forces applied to the blower 117. These first measuring means 118 can be formed by a thrust balance configured to measure forces applied to the blower 117.

[0051] The device 100 also comprises inlet guide vanes 119 arranged in the primary channel 104 and flow straightening vanes 120 arranged in the secondary channel 107.

[0052] The inlet guide vanes 119, the flow straightening vanes 120 and the cover 102 are mechanically connected to second means 121 for measuring the forces applied to the inlet guide vanes 119 and the flow straightening vanes 120.

[0053] These second measuring means 121 can be formed by a thrust balance configured to measure forces applied to the inlet guide vanes 119 as well as the flow straightening vanes 120.

[0054] The sealing ferrule 109 included in the device 100 according to the invention makes it possible to seal the primary channel 104 while allowing a possibility of movement between the weighed part and the fixed casing 103 without generating parasitic forces on the thrust measurements. Thanks to the invention, it is possible to demonstrate the counter-thrust capacity of a fan as well as the correct supply of a primary flow in condition reverse.

Claims

Claims

1. Device (100) modeling an aircraft propulsion unit (100) comprising a nacelle (101) with longitudinal axis X surrounding a shroud (102) with longitudinal axis X, said shroud (102) surrounding the upstream portion of a fixed casing (103) with a shroud with longitudinal axis X, said shroud (102) and said fixed casing (103) being independent of each other, a primary flow channel (104) being externally surrounded by said fixed casing (103) and a secondary flow channel (107) being formed between said shroud (102) and said nacelle (101), said device (100) being characterized in that it comprises a deformable sealing shroud (109), said sealing shroud (109) ensuring a seal between said shroud (102) and said fixed casing (103).

2. Device (100) according to the preceding claim, characterized in that the sealing ferrule (109) is arranged between a downstream end of said cover (102) and a downstream end of said fixed casing (103).

3. Device (100) according to any one of the preceding claims, characterized in that the sealing ferrule (109) comprises a first part (110) bearing on an external surface (106) of the fixed casing (103) and a second part (111) substantially perpendicular to said first part (110), said second part (111) bearing on a bearing surface (112) of the cover (102) substantially perpendicular to said external surface (106) of said fixed casing (103), said first part (110) being integral with said fixed casing (103) and said second part (111) being integral with said cover (102).

4. Device (100) according to any one of the preceding claims, characterized in that it comprises a blower (117) arranged at the inlet of the primary channel (104) and of the secondary channel (107), said blower (117) being mechanically connected to first means (118) for measuring the forces applied to said blower (117).

5. Device (100) according to any one of the preceding claims, characterized in that it comprises inlet guide vanes (119) arranged in the primary channel (104) and flow straightening vanes (120) arranged in the secondary channel (107), said inlet guide vanes (119), said flow straightening vanes (107) and said cover (102) being mechanically connected to second means (121) for measuring the forces applied to said di- inlet rectrices (119) and said flow straightening vanes (107).

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