Turbojet nacelle and method for controlling separation in a turbojet nacelle
View Patent ↗An aircraft turbojet nacelle comprising blowing means intended to inject a tangential airflow (F t ) into the internal volume (V) of the nacelle, said blowing means being provided in a wall of the air intake of the nacelle in the supersonic area of said air intake. The invention also concerns a method for controlling separation in an aircraft nacelle, wherein a tangential airflow is injected (F t ) into the internal volume (V) of the nacelle in the locally supersonic area of the air intake so as to pull the main airflow (F) into the extension of the inner wall of the nacelle.
1. Aircraft turbojet nacelle wherein it comprises blowing means intended to inject a tangential airflow (F 1 ) taken from outside the nacelle into an internal volume (V) of the nacelle, said blowing means being provided in a wall of an air intake of the nacelle in a supersonic area of said air intake, the blowing means comprising at least one air inlet line equipped with a rear end and a front end, the rear end ending at an outer wall of the nacelle and capable of taking the tangential airflow from outside the nacelle and the front end ending in the nacelle in the supersonic area proximate a forward lip of said air intake where airflow is locally supersonic.
2. The nacelle according to claim 1 , in which the blowing means end comprises at least one blowing slot ending in the internal volume of said nacelle.
3. The nacelle according to claim 1 , in which the tangential airflow has a pressure between 0.8 and 1.5 times the pressure of a main airflow (F).
4. The nacelle according to claim 1 , in which a pressure ratio between the tangential airflow injected into the internal volume of the nacelle and the main airflow circulating in the internal volume of the nacelle is close to 1.
5. The nacelle according to claim 1 , in which the blowing means comprise at least one blowing orifice ending in the internal volume of said nacelle.
6. The nacelle according to claim 1 , comprising means of sealing the blowing means.
7. The nacelle according to claim 1 , wherein the tangential airflow is injected over the entire inner perimeter of the nacelle.
8. The nacelle according to claim 2 , wherein the at least one blowing slot comprises three slots, wherein each of the three slots is capable of injecting a tangential airflow to the internal volume of the nacelle over one-third of the inner perimeter of the nacelle.
9. A method for controlling separation in an aircraft nacelle, comprising taking a tangential airflow (F t ) from outside the nacelle and injecting the tangential airflow into an internal volume (V) of the nacelle in a locally supersonic area of an air intake, proximate a forward lip of said air intake where airflow is locally supersonic, the tangential airflow acting on airstreams that tend to separate from an inner wall of the nacelle in a main airflow (F) to maintain such airstreams in attachment with the inner wall.
10. The method according to claim 9 , including injecting the tangential airflow when the aircraft is at a relatively low speed.
11. The method according to claim 9 , including ordering activation of the tangential airflow injection by means of deployment of high lift elements of an aircraft.
12. The method according to claim 9 , wherein the tangential airflow is injected over the entire inner perimeter of the aircraft nacelle.
13. The method according to claim 9 , wherein the tangential airflow is injected through three slots, wherein each of the three slots is capable of injecting a tangential airflow to the internal volume of the nacelle over one-third of the inner perimeter of the nacelle.