Abstract: A mould for obtaining an element is provided. The mould includes an outer face and a plurality of parallel ribs and/or grooves formed on the outer face. One of the walls of the mould includes ribs and/or grooves of which at least a portion of the ribs and/or grooves can be retracted, at least temporarily, such that at least a portion of the surface of the wall is smooth.

Abstract: The invention concerns an aircraft propulsion system comprising at least one member (1, 3, 4, 8) in contact with a turbulent flow of a stream (F), characterised in that said member is covered, at least partially, by a piezoelectric structure (S) such as a piezoelectric film, said structure (S) comprising a grooved structure (5, 6, 7, 9) comprising a series of grooves, in contact with the flow of the stream, the grooves extending in the direction of flow of the stream, the grooved structure comprising at least one geometric parameter (h, s, w) configured to adapt depending on at least one parameter of the flow of the stream and/or an operating point of the propulsion system and/or an engine speed of the propulsion system.

Abstract: A method for making an aerodynamic element, particularly for an aircraft, including an external face and a plurality of parallel ribs and/or grooves formed on the external face, the method including making the element and its ribs and/or its grooves simultaneously with a mold, including a step to supply a film made of a deformable material that includes ribs and/or grooves complementary to the ribs and/or grooves of the element, a step to position the film on a wall of the mold, a step in which the element is molded, a step in which the element is separated from the mold simultaneously with the film, and a step in which the film is separated from the element.

Abstract: The invention relates to a method for fire protection (S) of a part (1) of a gas-turbine engine made of a composite material comprising a main fibrous reinforcement compregnated by a main matrix, the protection method (S) comprising the following steps: preforming (S1) a panel of prepreg (20) such as to grant same a shape corresponding to the shape of a surface (3) of the part (1) to be protected against fire, said panel of prepreg (20) comprising a secondary fibrous reinforcement compregnated by a secondary matrix; applying (S2) the panel of prepreg (20) thus preformed to the part (1); and securing (S3) the panel of prepreg (20) to the surface (3) by thermal treatment of the part (1) provided with said panel of prepreg (20) in order to obtain a fire-protection layer (2).

Abstract: A mould for obtaining an element is provided. The mould includes an outer face and a plurality of parallel ribs and/or grooves formed on the outer face. One of the walls of the mould includes ribs and/or grooves of which at least a portion of the ribs and/or grooves can be retracted, at least temporarily, such that at least a portion of the surface of the wall is smooth.

Abstract: The invention concerns an aircraft propulsion system comprising at least one member (1, 3, 4, 8) in contact with a turbulent flow of a stream (F), characterised in that said member is covered, at least partially, by a piezoelectric structure (S) such as a piezoelectric film, said structure (S) comprising a grooved structure (5, 6, 7, 9) comprising a series of grooves, in contact with the flow of the stream, the grooves extending in the direction of flow of the stream, the grooved structure comprising at least one geometric parameter (h, s, w) configured to adapt depending on at least one parameter of the flow of the stream and/or an operating point of the propulsion system and/or an engine speed of the propulsion system.

Abstract: Method for forming a riblet on a component and riblet mould. This invention relates to a method for forming a riblet (3) on a component (1), characterised in that it comprises steps of: printing (106) the riblet on the component (1), comprising applying a film (1) comprising a riblet imprint (6) on the component (1), and peeling (108) the film (4) so as to separate the riblet imprint (6) from the component (1), after printing (106). This invention also relates to a riblet mould (3), the mould comprising a film (4) in which a riblet imprint (6) is formed, the film (4) being adapted to be separated from a component (1) on which a riblet (3) has been printed by means of the riblet mould (3), by peeling the film (4).

Abstract: A method for making an aerodynamic element, particularly for an aircraft, including an external face and a plurality of parallel ribs and/or grooves formed on the external face, the method including making the element and its ribs and/or its grooves simultaneously with a mold, including a step to supply a film made of a deformable material that includes ribs and/or grooves complementary to the ribs and/or grooves of the element, a step to position the film on a wall of the mold, a step in which the element is molded, a step in which the element is separated from the mold simultaneously with the film, and a step in which the film is separated from the element.

Abstract: The invention relates to a method for fire protection (S) of a part (1) of a gas-turbine engine made of a composite material comprising a main fibrous reinforcement compregnated by a main matrix, the protection method (S) comprising the following steps: preforming (S1) a panel of pre-preg (20) such as to grant same a shape corresponding to the shape of a surface (3) of the part (1) to be protected against fire, said panel of prepreg (20) comprising a secondary fibrous reinforcement compregnated by a secondary matrix; applying (S2) the panel of prepreg (20) thus preformed to the part (1); and securing (S3) the panel of prepreg (20) to the surface (3) by thermal treatment of the part (1) provided with said panel of prepreg (20) in order to obtain a fire-protection layer (2).

Abstract: The invention relates to a copolyamide comprising units resulting from the polycondensation reaction of the following precursors: terephthalic acid (a), an aliphatic diamine (b) comprising x carbon atoms, x being an integer between 6 and 22, and an aminocarboxylic acid and/or a lactam (c) comprising a main chain and at least one linear or branched alkyl branching, the total number of carbon atoms of the aminocarboxylic acid and/or of the lactam (c) being between 12 and 36. The invention also relates to the process for preparing said copolyamide and to a composition comprising such a copolyamide.