An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. The outer fan has a diameter of from 2.5 to 3.5 times a diameter of the inner fan.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. The outer fan has a diameter of from 2.5 to 3.5 times a diameter of the inner fan.

A rotating machine includes a plurality of rotors. Each of the rotors includes a rotor bore protruding radially inward from a platform. A ring shaped cover plate is interfaced with each rotor bore via at least one snap. The at least one snap includes a first arm extending from the cover plate and having a convex facing contact surface, and multiple second arms extending axially from each rotor bore and having contact surfaces facing the convex surface.

A rotating machine includes a plurality of rotors. Each of the rotors includes a rotor bore protruding radially inward from a platform. A ring shaped cover plate is interfaced with each rotor bore via at least one snap. The at least one snap includes a first arm extending from the cover plate and having a convex facing contact surface, and multiple second arms extending axially from each rotor bore and having contact surfaces facing the convex surface.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A swept area of the outer fan is from 2 to 20 times greater than a swept area of the inner fan.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A swept area of the outer fan is from 2 to 20 times greater than a swept area of the inner fan.

A counter-rotating turbine of an aircraft turbomachine, includes a casing including an endoscopy port configured for an endoscopy plug of a non-destructive testing device to pass into the casing. The endoscopy plug includes a mechanism for acquiring and transmitting images. The non-destructive testing device includes a mechanism for receiving and displaying images connected to the mechanism for acquiring and transmitting images by a wireless connection. First and second rotors are configured to rotate in opposite rotation directions, the second rotor having an endoscopy port in which the endoscopy plug is removably attached.

A counter-rotating turbine of an aircraft turbomachine, includes a casing including an endoscopy port configured for an endoscopy plug of a non-destructive testing device to pass into the casing. The endoscopy plug includes a mechanism for acquiring and transmitting images. The non-destructive testing device includes a mechanism for receiving and displaying images connected to the mechanism for acquiring and transmitting images by a wireless connection. First and second rotors are configured to rotate in opposite rotation directions, the second rotor having an endoscopy port in which the endoscopy plug is removably attached.

A gas turbine is provided, the gas turbine engine including a turbomachine having an inlet splitter defining in part an inlet to a working gas flowpath and a fan duct splitter defining in part an inlet to a fan duct flowpath. The gas turbine engine also includes a primary fan driven by the turbomachine defining a primary fan tip radius R1, a primary fan hub radius R2, and a primary fan specific thrust rating TP; and a secondary fan downstream of the primary fan and driven by the turbomachine, the secondary fan defining a secondary fan tip radius R3, a secondary fan hub radius R4, and a secondary fan specific thrust rating TS; wherein the gas turbine engine defines an Effective Bypass Area, and wherein a ratio of R1 to R3 equals

[00001]$\frac{R_1}{R_3}=\sqrt{\left(EFP\right)\frac{\left(1-{\mathrm{RqR}}_{\mathrm{Sec}.-\mathrm{Fan}}^2\right)}{\left(1-{\mathrm{RqR}}_{\mathrm{Prim}.-\mathrm{Fan}}^2\right)}\left(\frac{T_P}{T_S}\right)\left(EBA\right)}.$

A variable pitch bladed disc including a plurality of blades, each being of variable pitch about a blade axis of rotation and having a root, the plurality of blades including at least one first blade and at least one second blade, a plurality of rotor connecting shafts, each shaft having a root and a tip, the root of each blade being mounted on the tip of a corresponding rotor connecting shaft via a pivot so as to allow each blade to be rotated about the blade axis of rotation, the first blade having a first rotation axis inclination such that the rotation axis thereof is inclined in a fixed manner with respect to a radial axis passing through the root of the corresponding shaft, and the second blade has a second rotation axis inclination different from the first rotation axis inclination.