A clearance reducing system for turbomachinery is provided. In one embodiment, a turbomachinery apparatus having a shaft rotatable about an axis, with an impeller coupled to the shaft for rotation about the axis and a shroud positioned over at least a portion of the impeller is provided. The impeller includes a hub with a plurality of impeller blades projecting from the hub. An erodible element containing a mixture of a polymer with a first density and a filler with a second density, with the second density greater than the first density is also provided. The erodible element is located on a portion of the shroud opposite the impeller blades and structured to erode when contacted by the plurality of impeller blades.

The invention relates to a method for metering fuel in a fuel supply circuit of an aircraft engine, the circuit comprising a metering device for a fuel circuit of an aircraft engine comprising, downstream of a fuel pumping system and upstream of injectors: —a fuel inlet (E), —a metering device (FMV) and a cut-off device (HPSOV) arranged in series, —an adjustment valve (VR) arranged on a fuel recirculation branch, such that any excess fuel supplied by the pumping system is fed back into the fuel circuit, wherein at least one flow-metric sensor (WFM1) is arranged on the recirculation branch, a density value for the metered fuel is determined according to the sensor measurements and the metering device is controlled according to the fuel density value thus determined.

The disclosure describes articles and techniques that include an airfoil having a hybrid coating system to provide improved particle impact resistance and improve CMAS attack resistance on the pressure side of the airfoil and improved thermal load protection on the suction side of the airfoil. An example article for a gas turbine engine may include a substrate, and a hybrid environmental barrier coating (EBC) including a relatively dense EBC layer on a first portion of the substrate and a relatively porous EBC layer on a second portion of the substrate, where the first portion of the substrate is different from the second portion of the substrate, and wherein at least a portion of the relatively porous EBC layer overlaps at least a portion of the relatively dense EBC layer in an overlap region.

A turbomachine airfoil element includes an airfoil having pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 0.83-0.93 inch (21.1-23.6 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 0.80-0.90 inch (20.4-22.9 mm). The airfoil element includes at least two of a first mode with a frequency is 3135±10% Hz, a second mode with a frequency is 6634±10% Hz, a third mode with a frequency is 13260±10% Hz, a fourth mode with a frequency is 16838±10% Hz and a fifth mode with a frequency is 17980±10% Hz.

A turbomachine airfoil element includes an airfoil that has pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 1.01-1.15 inch (25.7-29.3 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 0.54-0.66 inch (13.6-16.8 mm). The airfoil element includes at least two of a first mode with a frequency of 2033 ± 15% Hz, a second mode with a frequency of 7023 ± 15% Hz, a third mode with a frequency of 12082 ± 15% Hz and a fourth mode with a frequency of 19769 ± 15% Hz.

A turbomachine airfoil element includes an airfoil having pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 0.60-0.70 inch (15.3-17.8 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 0.90-1.00 inch (22.9-25.5 mm). The airfoil element includes at least two of a first mode with a frequency of 5327±10% Hz, a second mode with a frequency of 8393±10% Hz, a third mode with a frequency of 16289±10% Hz, a fourth mode with a frequency of 25049±10% Hz and a fifth mode with a frequency of 27423±10% Hz.

A method of fabricating an abradable coating of varying density, and an abradable coating of varying density. The method comprises the following steps: providing a substrate having a first portion and a second portion; depositing a first precursor material on the first portion of the substrate; compressing the first precursor material between the substrate and a first bearing surface; sintering the first precursor material as compressed in this way in order to obtain a first abradable coating portion on the first portion of the substrate, and possessing a first density; depositing a second precursor material on the second portion of the substrate; and compressing the second precursor material between the substrate and a second bearing surface.

A turbomachine airfoil element includes an airfoil that has pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 4.47-4.77 inch (113.5-121.2 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 2.57-2.87 inch (65.3-72.9 mm). The airfoil element includes at least two of a first mode with a frequency of 297±10% Hz, a second mode with a frequency of 1035±10% Hz, a third mode with a frequency of 1488±10% Hz, a fourth mode with a frequency of 1524±10% Hz, a fifth mode with a frequency of 2855±10% Hz and a sixth mode with a frequency of 4462±10% Hz.

The present invention relates to a rotor blade shroud for a turbomachine, comprising a sealing tip and a support structure that abuts the sealing tip. The support structure has at least one intermediate region in which a structural segment is arranged, wherein the radially outwardly arranged surface of the support structure and of the structural segment forms an essentially planar surface. The present invention further relates to a rotor blade for a turbomachine, comprising a rotor blade shroud as well as two methods of manufacturing a rotor blade shroud and a method of manufacturing a rotor blade.

An engine control device may comprise a processor and a memory. The engine control device may be configured to modify a fuel flow based on a density of the fuel proximate a fuel nozzle. The engine control device may include a densimeter embedded in, or disposed proximate, the engine control device. The engine control device may include a temperature sensor embedded in, or disposed proximate, the engine control device. The engine control device may be electrically coupled to a fuel valve and/or configured to modulate the fuel valve based on a density of the fuel at the fuel valve.