Accelerating turbine engine rotating structure with compressed air

An assembly for an aircraft powerplant, comprising:

• a compressor section arranged with a flowpath extending longitudinally through the compressor section, the compressor section including a compressor rotor and a compressor vane structure, the compressor rotor rotatable about an axis and comprising a plurality of compressor blades, the plurality of compressor blades arranged circumferentially around the axis in a compressor blade array and disposed in the flowpath, the compressor vane structure comprising a plurality of compressor vanes, and the plurality of compressor vanes arranged circumferentially around the axis in a compressor vane array and disposed in the flowpath;
• and
• an air system including an air source, an air injector and an air circuit fluidly coupling the air source to the air injector, the air system configured to direct compressed air from the air source to the air injector through the air circuit, the air injector including a stem and a nozzle, the stem projecting radially into the flowpath from a flowpath wall to a radial distal end of the air injector and forming an exterior surface of the air injector, the nozzle branching and projecting laterally out from a portion of the stem to a tip of the nozzle, and the air injector configured to direct a jet of the compressed air into the flowpath and against the compressor blade array to apply a rotational driving force onto the compressor rotor about the axis;
• wherein the air injector projects radially into the flowpath, and the air injector is disposed at an injector location longitudinally between and adjacent the compressor vane array and the compressor blade array;
• and
• wherein the flowpath has a radial height at the injector location, and the air injector projects a radial distance into the flowpath at the injector location, the radial distance is between one-quarter and three-quarters of the radial height.

An assembly for an aircraft powerplant, comprising:

• a compressor section arranged with a flowpath extending longitudinally through the compressor section, the compressor section including a compressor rotor and a compressor vane structure, the compressor rotor rotatable about an axis and comprising a plurality of compressor blades, the plurality of compressor blades arranged circumferentially around the axis in a compressor blade array and disposed in the flowpath, the compressor vane structure comprising a plurality of compressor vanes, and the plurality of compressor vanes arranged circumferentially around the axis in a compressor vane array and disposed in the flowpath;
• and
• an air system including an air source, an air injector and an air circuit fluidly coupling the air source to the air injector, the air system configured to direct compressed air from the air source to the air injector through the air circuit, the air injector including a stem and a nozzle, the stem projecting radially into the flowpath from a flowpath wall to a radial distal end of the air injector and forming an exterior surface of the air injector, the nozzle branching and projecting laterally out from a portion of the stem to a tip of the nozzle, and the air injector configured to direct a jet of the compressed air into the flowpath and against the compressor blade array to apply a rotational driving force onto the compressor rotor about the axis;
• wherein the air injector projects radially into the flowpath, the air injector is disposed at an injector location longitudinally between and adjacent the compressor vane array and the compressor blade array, the air injector is discrete from the plurality of compressor vanes, the air injector is disposed circumferentially between and next to a respective circumferentially neighboring pair of the plurality of compressor vanes, the flowpath has a radial height at an injector location, the air injector has a radial distance into the flowpath at the injector location, and the radial distance is between one-quarter and three-quarters of the radial height.