US 11,920,540 B2
Gas turbine engine with a defined fan axis angle between a fan tip axis and a centerline
Benjamin J Sellers, Bath (GB); Stephen J Bradbrook, Clevedon (GB); Robert J Corin, Bristol (GB); and Richard J Hunsley, Bristol (GB)
Assigned to ROLLS-ROYCE plc, London (GB)
Filed by ROLLS-ROYCE plc, London (GB)
Filed on Sep. 8, 2022, as Appl. No. 17/940,034.
Claims priority of application No. 2112777 (GB), filed on Sep. 8, 2021.
Prior Publication US 2023/0167784 A1, Jun. 1, 2023
Int. Cl. F02K 3/06 (2006.01); F01D 15/10 (2006.01)
CPC F02K 3/06 (2013.01) [F01D 15/10 (2013.01); F05D 2220/323 (2013.01); F05D 2220/36 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A turbofan gas turbine engine for an aircraft, the gas turbine engine comprising, in axial flow sequence, a fan assembly, a compressor module, and a turbine module, with a first electric machine being positioned downstream of the fan assembly and being rotationally connected to the turbine module,
the fan assembly comprises a highest pressure fan stage having a plurality of fan blades extending radially from a hub, the plurality of fan blades defining a fan diameter (DFAN), each fan blade having a leading edge and a trailing edge, and the turbine module comprises a lowest pressure turbine stage having a row of rotor blades, with each of the rotor blades extending radially and having a leading edge and a trailing edge,
wherein the gas turbine engine has a fan tip axis that joins a radially outer tip of the leading edge of one of the plurality of fan blades of the highest pressure fan stage, and the radially outer tip of the trailing edge of one of the rotor blades of the lowest pressure turbine stage, the fan tip axis lying in a longitudinal plane which contains a centreline of the gas turbine engine, and a fan axis angle is defined as the angle between the fan tip axis and the centreline, and the fan axis angle is in a range between 11 degrees and 20 degrees,
wherein the fan assembly is fluidly connected to the compressor module by an intermediate duct that comprises a radially outer wall, an outer intermediate duct wall angle is defined as an angle between a radially inwardly facing surface of the radially outer wall and the centerline and the outer intermediate duct wall angle is −30 degrees, and
wherein the radially outer wall is between the fan assembly and a lowest-pressure compressor stage of the compressor module such that the intermediate duct fluidly connects the fan assembly to a leading edge of the lowest-pressure compressor stage.