Nacelle for an aircraft bypass turbojet engine

A nacelle for an aircraft dual flux turbojet engine having a longitudinal axis and an upstream section comprising an air intake structure equipped with an air intake lip, an internal wall of which defines a space for circulation of a main airflow, said nacelle comprising at least one device for modulating the cross-section of said space positioned in the wall of the air intake lip and including:

• means for injecting an auxiliary flow of a gas, configured for varying the orientation and/or the speed of said auxiliary flow by an induced ejector effect;
• means for drawing in at least one portion of this injected auxiliary flow;
• and
• an internal area for return of the auxiliary flow in one or several walls, said area being configured so as to form a cavity allowing the circulation of the portion of the injected auxiliary flow and of the drawn-in auxiliary flow and the contacting of a portion of the injected gas auxiliary flow and of the main airflow, comprising, in order to do this, at least one downstream aperture, configured for drawing in at least one portion of the gas in contact with the air of the main flow and an upstream outlet configured for allowing the circulation of the injected by the injection means and the gas circulating in the cavity,
• characterized in that the internal return area has an external front portion forming a striction area of the internal return area.