STARTER DEVICE FOR ROCKET MOTOR TURBOPUMP
The subject of the invention is a device for starting a turbopump of a rocket motor of an aircraft including a turbine engine for propelling the aircraft and a rocket motor, which includes a pneumatic supply of compressed air to a turbine of the turbopump, this compressed air being tapped from a tapping on a compressor stage of the aircraft propulsion turbine engine upstream of the combustion chamber of the turbine engine. It applies notably to an aircraft of the space airplane type.
1 . A device for starting a turbopump of a rocket motor of an aircraft including a turbine engine for propelling the aircraft and a rocket motor, the device comprising a pneumatic supply for starting a turbine of the turbopump via a circuit for injection of compressed air bled by means of a tapping from a compressor stage of the turbine engine for propelling the aircraft on the upstream side of the combustion chamber of said turbine engine.
2 . The device as claimed in claim 1 , further comprising a combustion chamber of a generator of gas for driving rotation of the turbine of the turbopump, said chamber being fed with liquid propellants when the rocket motor is operating.
3 . The device as claimed in claim 2 , wherein the circuit for injection of compressed air into the turbine is adapted to fill said chamber with said compressed air so as to inject oxygen gas with at least one liquid propellant or in a mixture of liquid propellants during the phase of ignition of the gas generator for improved starting of the combustion of these liquid propellants.
4 . The device as claimed in claim 1 further comprising means for cooling the bled air.
5 . The device as claimed in claim 4 wherein the cooling means comprises a heat exchanger cooled by air from outside the aircraft.
6 . The device as claimed in claim 4 wherein the cooling means use all or part of a line for feeding the rocket motor with cryogenic propellants.
7 . The device as claimed in claim 1 wherein the circuit for injection of compressed air for pneumatic supply of the turbine of the turbopump is equipped with a valve, calibration means and a check valve adapted to produce fast and controlled rotation of the turbine from the tapping.
8 . A system for propulsion of an aircraft including at least one propulsion turbine engine and at least one rocket motor, the system comprises a device according to claim 1 for starting a turbopump of the rocket motor.
9 . A space plane comprising a propulsion system as claimed in claim 8 .
10 . A hypersonic aircraft comprising a propulsion system as claimed in claim 8 .
11 . A method of starting a rocket motor turbopump by means of a device as claimed in claim 1 , the method comprising a first step of injection of compressed air into a turbine of the turbopump and then a step of injection of propellants into a combustion chamber of a generator of gas for driving the turbopump thanks to the driving of the turbine by the compressed air.
12 . The method as claimed in claim 11 , wherein the injection of air into the turbine is stopped by means of a valve when the pressure in the gas generator exceeds the setting of the valve.