Aircraft comprising a gas turbine engine having primary and secondary fuel-injectors
An aircraft includes an engine system which includes a gas turbine engine and a fuel system. The engine has combustion apparatus having an annular array of alternating primary and secondary fuel-injectors. The fuel system includes a fuel store and a controller. The controller is arranged to receive one or more signals indicative of one or more of (i) starting of the gas turbine engine; (ii) flame-out of the combustion apparatus; and (ii) a manoeuvring of the aircraft associated with a risk of flame-out of the combustion apparatus or preparation for such manoeuvring; and in response thereto to control the fuel system to commence supply of fuel from the fuel store to the secondary fuel-injectors of the combustion apparatus. Compared to known aircraft, engine lighting and relighting are achieved for more rapidly and reliably and the aircraft is less susceptible to flame-out, especially where hydrogen fuel is used.
1 . An aircraft comprising an engine system which includes:
(i) a gas turbine engine including combustion apparatus having a cylindrical outer casing and an annular array of alternating primary and secondary fuel-injectors arranged on a circumference of the cylindrical outer casing, each of the primary and secondary fuel-injectors having a respective fuel-emitting face; and
(ii) a fuel system comprising a fuel store and a controller;
wherein
(a) the fuel system is arranged to provide a fuel from the fuel store to the primary and secondary fuel-injectors, the fuel is hydrogen fuel;
(b) each primary and secondary fuel-injector is arranged to emit the fuel in a direction having a component that is parallel to a longitudinal axis of the cylindrical outer casing and is normal to a plane of the array; and
(c) the controller is arranged:
to determine whether one or more signals received, the one or more signals indicative of one or more of
(i) starting of the gas turbine engine;
(ii) flame-out of the combustion apparatus; and
(iii) a manoeuvring of the aircraft associated with a risk of flame-out of the combustion apparatus or preparation for such manoeuvring;
in response to determining that the one or more signals is received to control the fuel system to commence supply of the fuel from the fuel store to the secondary fuel-injectors of the combustion apparatus, and
in response to determining that the one or more signals is absent, to control the fuel system to not supply the fuel from the fuel store to the secondary fuel-injectors of the combustion apparatus.
2 . The aircraft according to claim 1 , wherein each primary fuel-injector is arranged to emit the fuel in a direction having a component in the plane of the array directed towards the fuel-emitting face of an adjacent secondary fuel-injector, each such component having the same sense with respect to the array.
3 . The aircraft according to claim 2 , wherein each primary fuel-injector is arranged to emit the fuel in first and second directions each having a respective component in the plane of the array directed towards the fuel-emitting face of a respective adjacent secondary fuel-injector.
4 . The aircraft according to claim 1 , wherein each secondary fuel-injector is arranged to emit the fuel in a direction having a component in the plane of the array directed towards the fuel-emitting face of an adjacent primary fuel-injector, each such component having the same sense with respect to the array.
5 . The aircraft according to claim 4 , wherein each secondary fuel-injector is arranged to emit the fuel in first and second directions each having a respective component in the plane of the array directed towards the fuel-emitting face of a respective adjacent primary fuel-injector.
6 . The aircraft according to claim 1 , wherein each primary fuel-injector is arranged to emit the fuel in a single direction, said single direction having a component in the plane of the array directed towards the fuel-emitting face of an adjacent secondary fuel-injector, each such component having the same sense with respect to the array.
7 . A method of operating combustion apparatus which comprises a cylindrical outer casing and an annular array of alternating primary and secondary fuel-injectors arranged on a circumference of the cylindrical outer casing, each primary and secondary fuel-injector being arranged to emit hydrogen fuel in a direction having a component that is parallel to a longitudinal axis of the cylindrical outer casing and is normal to a plane of the array, and the combustion apparatus being comprised in a gas turbine engine of an aircraft, the method comprising the steps of
(i) providing the hydrogen fuel to the primary fuel-injectors;
(ii) determining whether one or more signals is received the one or more signals indicative of one or more of
(a) starting of the gas turbine engine;
(b) flame-out of the combustion apparatus; and
(c) manoeuvring of the aircraft associated with a risk of flame-out of the combustion apparatus, or preparation for such manoeuvring; and
(iii) in response to determining that the one or more signals is received, commencing supply of the hydrogen fuel from a fuel store to the secondary fuel-injectors of the combustion apparatus, and
(iv) in response to determining that the one or more signals is absent, controlling the fuel store to not supply the hydrogen fuel to the secondary fuel-injectors of the combustion apparatus.