Abstract: The invention relates to the rating (S) of a propulsion unit (2) comprising a main engine (3) providing main thrust assisted by an auxiliary engine (4) providing auxiliary thrust, according to the following steps: (i) determining (S1) a distribution between the main thrust and the auxiliary thrust so as to obtain the takeoff thrust of the propulsion unit, the auxiliary thrust making a 5% to 65% contribution to the takeoff thrust, (ii) depending on the distribution determined for the takeoff condition, determining (S2) distribution between the main thrust and the auxiliary thrust so its to obtain the top of climb thrust of the propulsion unit, the auxiliary thrust making at most 70% contribution to the top of climb thrust, and (iii) rating (S3) the propulsion unit (2) in such a way that the main thrust of the main engine (3) determined fir the takeoff condition corresponds to the maximum thrust likely to be achieved by the main engine (3).

Abstract: Engine comprising a propeller unit with a pair of contrarotating propellers (31, 32), a gas generator (5) supplying a power turbine (53), the pair of propellers being rotationally driven by the shaft (53A) of the power turbine via a speed reduction gearbox, the axis of rotation (XX) of the pair of propellers not being coaxial with that (YY) of the power turbine, the speed reduction gearbox comprising a differential gearset (7) and a first stage (6) comprising a simple gearset connecting the turbine shaft (53A) and the differential gearset (7), the engine air intake comprising an air intake duct (11), the air intake duct (11) being in the shape of a lobe adjacent to the assembly formed by the simple gearset and the differential gearset (7).

Abstract: The invention relates to the rating (S) of a propulsion unit (2) comprising a main engine (3) providing main thrust assisted by an auxiliary engine (4) providing auxiliary thrust, according to the following steps: (i) determining (S1) a distribution between the main thrust and the auxiliary thrust so as to obtain the takeoff thrust of the propulsion unit, the auxiliary thrust making a 5% to 65% contribution to the takeoff thrust, (ii) depending on the distribution determined for the takeoff condition, determining (S2) distribution between the main thrust and the auxiliary thrust so its to obtain the top of climb thrust of the propulsion unit, the auxiliary thrust making at most 70% contribution to the top of climb thrust, and (iii) rating (S3) the propulsion unit (2) in such a way that the main thrust of the main engine (3) determined fir the takeoff condition corresponds to the maximum thrust likely to be achieved by the main engine (3).

Abstract: A propulsion unit for an aircraft is provided. The propulsion unit includes a main engine that supplies main thrust during a takeoff operating condition and a top of climb operating condition, and an auxiliary engine, distinct from the main engine, that supplies auxiliary thrust to complete the main thrust of the main engine during the takeoff operating condition. The main engine includes a high-pressure compressor. The main engine is dimensioned taking into account the thrust of the auxiliary engine in the takeoff operating condition, in such a manner that a temperature ratio of the high-pressure compressor, corresponding to the ratio between an outlet temperature of the high-pressure compressor of the main engine in the top of climb operating condition and an outlet temperature of the high-pressure compressor of the main engine in the takeoff operating condition, is between 0.90 and 1.10.

Abstract: Engine comprising a propeller unit with a pair of contrarotating propellers (31, 32), a gas generator (5) supplying a power turbine (53), the pair of propellers being rotationally driven by the shaft (53A) of the power turbine via a speed reduction gearbox, the axis of rotation (XX) of the pair of propellers not being coaxial with that (YY) of the power turbine, the speed reduction gearbox comprising a differential gearset (7) and a first stage (6) comprising a simple gearset connecting the turbine shaft (53A) and the differential gearset (7), the engine air intake comprising an air intake duct (11), the air intake duct (11) being in the shape of a lobe adjacent to the assembly formed by the simple gearset and the differential gearset (7).