Abstract: A method of designing an external geometry of an aircraft lifting surface, including the steps of defining a geometric shape corresponding to an initial lifting surface according to a planform, wherein the initial lifting surface is defined by at least five geometry parameters and a plurality of shape modifier parameters of the lifting surface, modifying the geometric shape of the initial lifting surface by applying a spanwise function to a shape modifier parameter of the initial lifting surface to obtain a modified lifting surface, defining a thickness of an airfoil at a given span position along the span of the modified lifting surface obtained in the modifying step based on a predefined airfoil, and defining the external geometry of the aircraft final lifting surface by interpolating the airfoil along the span of the modified lifting surface via a transition function.

Abstract: A propulsion engine comprising at least a first propulsion unit including a first fan encased by a geared ring and a gas turbine engine driving a first shaft connected to the first fan, at least a second propulsion unit including a second fan encased by a geared ring connected to a second shaft operatively coupled to an electric machine and at least an electric storage device connected to the electric machine. The geared rings are configured to transmit torque between the fans so that they can rotate in conjunction (directly or through an intermediate gear) when they are driven by at least one of said first and second shafts. The propulsion engine is arranged for controlling the torque to be supplied to the assembly of the first and second fans by the gas turbine engine and/or by the electric machine acting as a motor or as a generator.

Abstract: A multi-fan engine including a gas turbine engine, a casing and fans encased by geared rings, which connect with the geared rings of an adjacent fan(s) such that the rotation of one fan rotates the other fans. Intermediate gears may prove the connection between adjacent geared rings, wherein the intermediate gears are retracted by linear actuators to disengage the intermediate gears from the geared rings and thereby disengage the fans from each other. The multi-fan engine may be mounted flush to the fuselage of an aircraft invention to capture into the fans boundary layer airflow moving over the skin of the fuselage.

Abstract: A multi-fan engine including a gas turbine engine, a casing and fans encased by geared rings, which connect with the geared rings of an adjacent fan(s) such that the rotation of one fan rotates the other fans. Intermediate gears may prove the connection between adjacent geared rings, wherein the intermediate gears are retracted by linear actuators to disengage the intermediate gears from the geared rings and thereby disengage the fans from each other. The multi-fan engine may be mounted flush to the fuselage of an aircraft invention to capture into the fans boundary layer airflow moving over the skin of the fuselage.

Abstract: A propulsion engine comprising at least a first propulsion unit including a first fan encased by a geared ring and a gas turbine engine driving a first shaft connected to the first fan, at least a second propulsion unit including a second fan encased by a geared ring connected to a second shaft operatively coupled to an electric machine and at least an electric storage device connected to the electric machine. The geared rings are configured to transmit torque between the fans so that they can rotate in conjunction (directly or through an intermediate gear) when they are driven by at least one of said first and second shafts. The propulsion engine is arranged for controlling the torque to be supplied to the assembly of the first and second fans by the gas turbine engine and/or by the electric machine acting as a motor or as a generator.