Thrust reverser with sealing membrane and retention system

A thrust reverser for an aircraft propulsion unit, the thrust reverser comprising:

• a fixed structure having a front frame and an internal delimiting wall for a secondary flow path of the aircraft propulsion unit, the secondary flow path configured to be traversed by a secondary flow in a general direction of flow,
• a movable structure including at least one cowl, the movable structure movable in translation relative to the fixed structure along a longitudinal central axis of the thrust reverser between a thrust position and a thrust reversal position,
• at least one sealing membrane configured to divert at least part of the secondary flow outwards through a radial opening formed between the front frame and the movable structure in the thrust reversal position, and the at least one sealing membrane extends into the secondary flow path in the thrust reversal position,
• at least one retention system that cooperates with the fixed structure and the at least one sealing membrane, the at least one retention system configured to apply a return force to the at least one sealing membrane, the return force comprising a component opposite to the general direction of flow in the thrust reversal position,
• wherein the fixed structure includes a rear frame, the at least one sealing membrane having a first end coupled to the rear frame,
• wherein the at least one cowl comprises an external delimiting wall configured to delimit the secondary flow path with the internal delimiting wall in the thrust position and an external panel having an outer aerodynamic surface of the thrust reverser,
• wherein the at least one cowl has a cavity open towards the front frame in the thrust position and formed between the external delimiting wall and the external panel, the rear frame located in the cavity in the thrust position so that the at least one sealing membrane is at least partially in the cavity in the thrust position, and
• wherein the at least one retention system comprises a connecting element configured to cooperate with a fastening point of the fixed structure on one end of the connecting element and configured to cooperate with the at least one sealing membrane at an attachment point on another end of the connecting element, and the attachment point is in the cavity in the thrust position.