Patent ID: 11859565
Assignee: ROLLS-ROYCE PLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 16:
17. A propulsion system for an aircraft comprising:
a gas turbine engine comprising:
a combustor arranged to combust a fuel and having an exit, and wherein a combustor exit pressure—P40—is defined as the total pressure at the combustor exit at cruise conditions;
a turbine comprising a rotor having a leading edge and a trailing edge, and wherein a turbine rotor entry pressure—P41—is defined as the total pressure at the leading edge of the rotor of the turbine at the cruise conditions; and
a compressor having an exit, wherein a compressor exit pressure—P30—is defined as the total pressure at the exit from the compressor at the cruise conditions;

a fuel tank arranged to contain the fuel to power the gas turbine engine; and
a processor programmed to:
change the fuel supplied to the gas turbine engine;
receive data corresponding to at least one of P30, P40 and P41; and
determine at least one fuel characteristic of the fuel based on a change in the at least one of P30, P40 and P41, the at least one fuel characteristic comprising at least one of:

i. a percentage of sustainable aviation fuel in the fuel; and
ii. an indication that the fuel is a fossil fuel.