US 12,241,409 B2
Aircraft propulsion system
Peter Swann, Derby (GB)
Assigned to ROLLS-ROYCE plc, London (GB)
Filed by ROLLS-ROYCE plc, London (GB)
Filed on Feb. 6, 2023, as Appl. No. 18/164,858.
Claims priority of application No. 2202791 (GB), filed on Mar. 1, 2022.
Prior Publication US 2023/0279808 A1, Sep. 7, 2023
Int. Cl. F02C 6/20 (2006.01); B64D 27/02 (2006.01); F02C 9/28 (2006.01); F02C 9/42 (2006.01)
CPC F02C 6/20 (2013.01) [B64D 27/02 (2013.01); F02C 9/28 (2013.01); F02C 9/42 (2013.01); B64D 27/026 (2024.01); F05D 2220/323 (2013.01); F05D 2220/76 (2013.01); F05D 2270/08 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An aircraft propulsion system comprising:
at least two engines, each engine having: a propulsive fan and an engine core, the engine core comprising a compressor, a combustor and a turbine driven by a flow of combustion products from the combustor, the propulsive fan configured to generate a mass flow of air that bypasses the engine core to generate thrust;
a first electrical machine coupled to a first engine, the first electrical machine arranged to be driven by electrical power in order to at least partially drive the first engine;
a second electrical machine coupled to a second engine, the second electrical machine arranged to be driven by the second engine to generate electrical power;
an electrical network arranged to allow transmission of electrical power between the first electrical machine and the second electrical machine; and
a controller arranged to, based on expected properties of contrails formed in an exhaust plume of the first engine and/or second engine, selectively reduce fuel flow to the first engine, and provide electrical power from the second electrical machine to the first electrical machine, to drive the first electrical machine.