A tandem rotor disk apparatus may include a rotor disk body concentric about an axis. The tandem rotor disk apparatus may also include a first blade extending radially outward of the rotor disk body and a second blade extending radially outward of the rotor disk body. The first blade may be offset from the second blade in a direction parallel to the axis. The tandem rotor disk apparatus may be implemented in a gas turbine engine with no intervening stator vane stages disposed between the first blade and the second blade.

A fluid machine for an aircraft engine has: first and second walls; a gaspath defined between the first wall and the second wall; a rotor having blades rotatable about the central axis; and a stator having: a row of vanes having airfoils including leading edges, trailing edges, pressure sides and suction sides opposed the pressure sides, and depressions defined in the first wall, the depressions extending from a baseline surface of the first wall away from the second wall, a depression of the depressions located circumferentially between a pressure side of the pressure sides and a suction side of the suction sides, the depression axially overlapping the airfoils and located closer to the suction side than to the pressure side, an upstream end of the depression located closer to a leading edge of the leading edges than to a trailing edge of the trailing edges.

A lifting foil having a configuration with a leading course and trailing course which is rotated about an axis of rotation into a fluid.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

A blade row group arrangeable in a main flow path of a fluid-flow machine includes N adjacent member blade rows firmly arranged relative to each other in both a meridional direction (m) and a circumferential direction (u). A relative secondary passage length (v′) and a relative secondary passage width (w′) each increase at least in one part of the area between the mean meridional flow line (SLM) and at least one of the main flow path boundaries (HB) towards the main flow path boundary (HB).

A tandem tip blade includes a main blade body, a front blade and a rear blade. The front blade extends from a main body end. Each of a front blade pressure and a front blade suction side extends between a front blade leading edge and a front blade trailing edge and a front blade tip extending from the front blade pressure side to the front blade suction side. The rear blade extends from the main body end. Each of a rear blade pressure side and a rear blade suction side extends between a rear blade leading edge and a rear blade trailing edge, and a rear blade tip extending from the rear blade pressure side to the rear blade suction side.

The present invention relates to a blade row group arrangeable in a main flow path of a fluid-flow machine and including N adjacent member blade rows firmly arranged relative to one another in both the meridional direction and the circumferential direction, with the number N of the member blade rows being greater than/equal to 2 and (i) designating the running index with values between 1 and N, with a front member blade row (i) as well as a rear member blade row (i+1) being provided, and with the blade row group having two main flow path boundaries. It is provided that there is a gap between one blade end of at least one blade of at least one of the member blade rows and at least one of the two main flow path boundaries.

Rotor assemblies for aircraft are described that include a plurality of blades that are disposed vertically on a common axis along different horizontal planes. When the rotor assemblies are free-wheeling, the blades form a vertically stacked configuration, and when the rotor assembly is driven in rotation to generate lift, the blades bloom out from the vertically stacked configuration. At least one of the blades in the rotor assembly has a blade geometry that is different with respect to other blades such that when the blades are vertically stacked and free-wheeling, the collective shape of the blades is aerodynamic in shape, based on the different blade geometry, that reduces aerodynamic drag on the rotor assembly.

A blade cascade of a continuous-flow machine is disclosed. The blade cascade has at least one side wall that is constructed in a wave-like manner in the peripheral direction and has at least one elevation and at least one depression. At least a profile-like rib is integrated in or combined with the side wall, which has a blade profile with a pressure side and with an opposite suction side. A continuous-flow machine with such a blade cascade is also disclosed.