Abstract: A gas turbine engine includes a compressor section and a compressor case with a low pressure compressor (LPC) and a high pressure compressor (HPC). The HPC is aft of the LPC. The compressor case defines a centerline axis. The compressor section also includes a rotor disk defined between the compressor case and the centerline axis. A plurality of stages are defined radially inward relative to the compressor case. The plurality of stages include at least one tandem blade stage. The tandem blade stage includes a plurality of blade pairs. Each blade pair is circumferentially spaced apart from the other blade pairs, and is operatively connected to the rotor disk. Each blade pair includes a forward blade and an aft blade. The aft blade is configured to further condition air flow with respect to the forward blade without an intervening stator vane stage shrouded cavity therebetween.

Abstract: 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 0.46-0.59 inch (11.8-14.9 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 0.73-0.86 inch (18.6-21.9 mm). The airfoil element includes at least two of a first mode with a frequency of 5133±15% Hz, a second mode with a frequency of 8542±15% Hz, a third mode with a frequency of 15487±15% Hz, a fourth mode with a frequency of 18774±15% Hz, a fifth mode with a frequency of 24295±15% Hz and a sixth mode with a frequency of 27084±15% Hz.

Abstract: A turbomachine airfoil element includes an airfoil that 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 0.46-0.58 inch (11.6-14.7 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span is in a range of 0.66-0.79 inch (16.7-20.0 mm. A first mode has a frequency of 35681±15% Hz and a second mode has a frequency of 39218±15% Hz.

Abstract: A gas turbine engine includes a compressor section and a compressor case with a low pressure compressor (LPC) and a high pressure compressor (HPC). The HPC is aft of the LPC. The compressor case defines a centerline axis. The compressor section also includes a rotor disk defined between the compressor case and the centerline axis. A plurality of stages are defined radially inward relative to the compressor case. The plurality of stages include at least one tandem blade stage. The tandem blade stage includes a plurality of blade pairs. Each blade pair is circumferentially spaced apart from the other blade pairs, and is operatively connected to the rotor disk. Each blade pair includes a forward blade and an aft blade. The aft blade is configured to further condition air flow with respect to the forward blade without an intervening stator vane stage shrouded cavity therebetween.

Abstract: A gas turbine engine includes a compressor section and a compressor case with a low pressure compressor (LPC) and a high pressure compressor (HPC). The HPC is aft of the LPC. The compressor case defines a centerline axis. The compressor section also includes a rotor disk defined between the compressor case and the centerline axis. A plurality of stages are defined radially inward relative to the compressor case. The plurality of stages include at least one tandem blade stage. The tandem blade stage includes a plurality of blade pairs. Each blade pair is circumferentially spaced apart from the other blade pairs, and is operatively connected to the rotor disk. Each blade pair includes a forward blade and an aft blade. The aft blade is configured to further condition air flow with respect to the forward blade without an intervening stator vane stage shrouded cavity therebetween.

Abstract: A cantilevered airfoil includes, among other things, an airfoil having a body section and a tip, the body section extending in a first direction that is angled relative to a radial direction, the tip of the airfoil angled radially in a second direction relative to the body section.

Abstract: A rotor includes a rotor hub that is rotatable about an axis. The rotor hub includes a bore portion and a rim. An arm extends axially and radially inwardly from the rim. The arm has a radially inner side, a radially outer side, and a protruding ramp on the radially outer side.

Abstract: An airfoil includes a stator vane that has a platform with a first radial side and a second radial side, and a platform axial leading end and a platform axial trailing end. An airfoil portion extends radially outwardly from the first side. The platform axial trailing end includes a rear axial face that extends from the first radial side and a radially sloped face that extends from the rear axial face to the second radial side.

Abstract: A gas turbine engine has a compressor section with a downstream most blade stage and a downstream vane row positioned downstream of the downstream most blade stage. The downstream most blade stage includes a plurality of blade pairs with the majority of blade pairs being circumferentially spaced apart from others of the blade pairs, each the blade pair being operatively connected to a rotor disk disposed radially inward from the blade pairs with each blade pair including a forward blade and an aft blade. The aft blades are configured to further condition airflow with respect to the forward blade. A tangential onboard injector (TOBI) is positioned radially inwardly of the downstream vane row.

Abstract: An airfoil includes a stator vane that has a platform with a first radial side and a second radial side, and a platform axial leading end and a platform axial trailing end. An airfoil portion extends radially outwardly from the first side. The platform axial trailing end includes a rear axial face that extends from the first radial side and a radially sloped face that extends from the rear axial face to the second radial side.

Abstract: A rotor includes a rotor hub that is rotatable about an axis. The rotor hub includes a bore portion and a rim. An arm extends axially and radially inwardly from the rim. The arm has a radially inner side, a radially outer side, and a protruding ramp on the radially outer side.

Abstract: A gas turbine engine includes a compressor section and a compressor case with a low pressure compressor (LPC) and a high pressure compressor (HPC). The HPC is aft of the LPC. The compressor case defines a centerline axis. The compressor section also includes a rotor disk defined between the compressor case and the centerline axis. A plurality of stages defined radially inward relative to the compressor case. The plurality of stages includes at least one tandem blade stage. The tandem blade stage includes a plurality of blade pairs. Each blade pair is circumferentially spaced apart from the other blade pairs, and is operatively connected to the rotor disk. Each blade pair includes a forward blade and an aft blade. The aft blade is configured to further condition air flow with respect to the forward blade without an intervening stator vane stage shrouded cavity therebetween.

Abstract: A cantilevered airfoil includes, among other things, an airfoil having a body section and a tip, the body section extending in a first direction that is angled relative to a radial direction, the tip of the airfoil angled radially in a second direction relative to the body section.