Turbojet engine for aircraft, propulsion unit comprising such a turbojet engine and aircraft comprising such a propulsion unit

1. A propulsion unit comprising:

a turbojet engine including—

a fan having an airstream inlet, a plurality of rotating blades, and an airstream outlet,

a static, air-stream guiding blade positioned at the airstream outlet of the fan, the guiding blade having an interior volume bounded by one or more panels;

a thermal exchanger positioned above the turbojet engine;

a cooling air lead-in conduit adapted to supply the thermal exchanger with cool air tap, the cooling air lead-in conduit being in fluid communication at a first end with the interior volume of the guiding blade, and the thermal exchanger at a second end; and

a regulation device adapted to regulate an air flow rate of cool air in the cooling air lead-in conduit, the regulation device including—

a door shiftably coupled to a panel of the guiding blade, the door being shiftable between an open position in which at least a portion of cool air from the airstream outlet of the fan is deflected into the interior volume of the guiding blade and into the cooling air lead-in conduit, and a closed position in which the cool air from the airstream outlet of the fan is blocked from entering the interior volume of the guiding blade, and therefore the cooling air lead-in conduit.

2. The propulsion unit of claim 1 , wherein the internal volume of the guiding blade at least partially forms the cooling air lead-in conduit.

3. The propulsion unit of claim 1 , wherein the regulation device further includes an actuation system adapted to modulate the air flow rate of cool air in the cooling air lead-in conduit according to cooling air requirements of the thermal exchanger.

4. The propulsion unit of claim 3 , wherein the actuation system comprises a link-rod to shift the door between the open position and the closed position.

5. The propulsion unit of claim 1 , wherein the guiding blade is fixedly joined to a bifurcation positioned at the airstream outlet of the fan, the bifurcation separating an outlet airstream from the fan into two secondary streams.

6. The propulsion unit of claim 5 , wherein the propulsion unit is adapted for use with an aircraft having a wing, wherein the turbojet engine is coupled to the wing by a fastening mast, and wherein the secondary streams flow respectively along a left flank and a right flank of a fastening mast.

7. The propulsion unit of claim 1 , wherein the door has internal travel.

8. The propulsion unit of claim 1 , wherein the door has external travel.

9. An aircraft comprising at least one propulsion unit according to claim 1 .