Fuel injection system for aircraft turbomachine, comprising a variable section air through duct

An aircraft turbomachine comprising:

• a combustion chamber including a chamber bottom perforated with openings spaced apart from one another;
• an assembly associated with each opening of the chamber bottom, the assembly including an injection system for the combustion chamber and a fuel injector engaging with said injection system, the injection system comprising:
• an aerodynamic bowl which is stationary with respect to the fuel injector and comprising a first widening end widening toward a downstream end thereof and centered on a central axis of the injection system,
• a central body along which a film of fuel is intended to flow in the downstream direction, the central body comprising a second widening end widening toward a downstream end thereof and centered on the central axis of the injection system, said first and second widening ends delimiting therebetween an air through duct, and
• an actuator which moves the central body relative to the injector so as to allow a relative movement between said first and second widening ends along the central axis of the injection system;
• and
• a control unit configured to control the actuator in order to vary a cross-section of the air through duct based on a speed of the aircraft turbomachine.