Abstract: In an aspect, a method is provided for attenuating jet engine noise. Air velocity, adjacent to an inlet fan duct outer wall, is increased to a greater rate than typical velocity of an operational engine ambient inlet airflow, adjacent to the inlet fan duct outer wall. Boundary layer and associated turbulence is reduced or eliminated. Refraction and absorption of inlet sound into an acoustic liner is optimized. In an aspect, air velocity is increased by injecting air. In an aspect, air velocity is increased by exerting a suction force. In an aspect, a system is provided to attenuate jet engine noise. In an aspect, a fluid duct is provided opening to an inlet fan duct outer wall and to aft of a fan rotor.

Abstract: A system for jet engine noise control of a jet engine having a main jet stream exiting an exhaust nozzle and flowing along a jet axis includes a thermal acoustic shield directed at a non-zero angle relative to the jet axis. The thermal acoustic shield may be configurable about the main jet stream. The system may further include at least a fluidic chevron injected at a location relative to the nozzle exit for enhancing mixing in the main jet stream and creating a non-circular jet stream.

Abstract: A bypass channel for use in an inter-turbine transition duct assembly of a turbine engine is connected to a suction port disposed upstream of a high-pressure turbine and at least two injection openings disposed downstream of the high-pressure turbine. The flow through the bypass channel is motivated by the natural pressure difference across the high-pressure turbine. The flow out of the at least two injection openings is used to energize the boundary layer flow downstream of the high-pressure turbine in order to allow for the use of a more aggressively expanded inter-turbine duct without boundary layer separation. Methods for optimizing the flow through the turbine engine are also disclosed.

Abstract: A bypass channel for use in an inter-turbine transition duct assembly of a turbine engine is connected to a suction port disposed upstream of a high-pressure turbine and at least two injection openings disposed downstream of the high-pressure turbine. The flow through the bypass channel is motivated by the natural pressure difference across the high-pressure turbine. The flow out of the at least two injection openings is used to energize the boundary layer flow downstream of the high-pressure turbine in order to allow for the use of a more aggressively expanded inter-turbine duct without boundary layer separation. Methods for optimizing the flow through the turbine engine are also disclosed.

Abstract: A bypass channel for use in an inter-turbine transition duct of a gas turbine engine is connected to a suction port disposed upstream of a high-pressure turbine and an injection port disposed downstream of the high-pressure turbine. The flow through the bypass channel is motivated by the natural pressure difference across the high-pressure turbine. The flow out of the injection nozzle is used to energize the boundary layer flow downstream of the high-pressure turbine in order to allow for the use of a more aggressively expanded inter-turbine duct without boundary layer separation.

Abstract: A bypass channel for use in an inter-turbine transition duct of a gas turbine engine is connected to a suction port disposed upstream of a high-pressure turbine and an injection port disposed downstream of the high-pressure turbine. The flow through the bypass channel is motivated by the natural pressure difference across the high-pressure turbine. The flow out of the injection nozzle is used to energize the boundary layer flow downstream of the high-pressure turbine in order to allow for the use of a more aggressively expanded inter-turbine duct without boundary layer separation.

Abstract: A diffuser includes an opening along the diffuser wall for preventing or delaying boundary layer separation of the main flow. The opening may include a curved passageway having a curvature convex relative to the main flow for utilizing the Coanda effect. A gas turbine may include the diffuser with an opening and a centerbody with an opening, each for providing a secondary flow of fluid into the diffuser. The gas turbine may direct fluid from an upstream turbine stage to the opening. A steam turbine may include the diffuser and may situate the opening downstream the diffuser inlet but upstream the location of boundary separation.

Abstract: In an aspect, a method is provided for attenuating jet engine noise. Air velocity, adjacent to an inlet fan duct outer wall, is increased to a greater rate than typical velocity of an operational engine ambient inlet airflow, adjacent to the inlet fan duct outer wall. Boundary layer and associated turbulence is reduced or eliminated. Refraction and absorption of inlet sound into an acoustic liner is optimized. In an aspect, air velocity is increased by injecting air. In an aspect, air velocity is increased by exerting a suction force. In an aspect, a system is provided to attenuate jet engine noise. In an aspect, a fluid duct is provided opening to an inlet fan duct outer wall and to aft of a fan rotor.

Abstract: In various embodiments, the present invention provides a means for improving gas turbine engine performance by applying fluid flow control to the inter-turbine duct joining a high-pressure turbine spool and an associated low-pressure turbine spool, allowing the low-pressure turbine spool to have a relatively larger diameter than the high-pressure turbine spool. One or more unobstructed fluid flow paths between one or more boundary layer suction ports disposed within the upstream end of the outer-body surface of the inter-turbine duct and the suction side of the associated low-pressure turbine nozzle are provided. Advantageously, the natural static pressure difference between these points results in a self-aspirating assembly. The fluid flow control provided by the respective suction and blowing forces generated allows for a relatively larger diameter low-pressure turbine spool and/or relatively fewer low-pressure turbine nozzles to be used than is possible with conventional systems, assemblies, and methods.

Abstract: A system for jet engine noise control of a jet engine having a main jet stream exiting an exhaust nozzle and flowing along a jet axis includes a thermal acoustic shield directed at a non-zero angle relative to the jet axis. The thermal acoustic shield may be configurable about the main jet stream. The system may further include at least a fluidic chevron injected at a location relative to the nozzle exit for enhancing mixing in the main jet stream and creating a non-circular jet stream.

Abstract: A flow control device for a combustor is provided in which the flow control device comprises a shroud having a first end and a second end wherein the second end is coupled to the combustor. The shroud is disposed to receive a primary fluid and disposed to direct the primary fluid into the combustor. In addition, the shroud further comprises a plurality of ports disposed therein wherein the ports are oriented to extract a portion of a flow from a flow path of the primary fluid so as to control a flow rate of the primary fluid through the shroud.

Abstract: A diffuser includes an opening along the diffuser wall for preventing or delaying boundary layer separation of the main flow. The opening may include a curved passageway having a curvature convex relative to the main flow for utilizing the Coanda effect. A gas turbine may include the diffuser with an opening and a centerbody with an opening, each for providing a secondary flow of fluid into the diffuser. The gas turbine may direct fluid from an upstream turbine stage to the opening. A steam turbine may include the diffuser and may situate the opening downstream the diffuser inlet but upstream the location of boundary separation.

Abstract: In various embodiments, the present invention provides a means for improving gas turbine engine performance by applying fluid flow control to the inter-turbine duct joining a high-pressure turbine spool and an associated low-pressure turbine spool, allowing the low-pressure turbine spool to have a relatively larger diameter than the high-pressure turbine spool. One or more unobstructed fluid flow paths between one or more boundary layer suction ports disposed within the upstream end of the outer-body surface of the inter-turbine duct and the suction side of the associated low-pressure turbine nozzle are provided. Advantageously, the natural static pressure difference between these points results in a self-aspirating assembly. The fluid flow control provided by the respective suction and blowing forces generated allows for a relatively larger diameter low-pressure turbine spool and/or relatively fewer low-pressure turbine nozzles to be used than is possible with conventional systems, assemblies, and methods.

Abstract: An active effective flow-through area control system includes an upstream wall-flow perturber and a downstream wall-flow perturber situated in an inlet region of an aircraft engine. The downstream wall-flow perturber is positioned downstream from the upstream wall-flow perturber. The upstream and downstream wall-flow perturbers are configured to generate and trap at least one region of separated, vortical flow in the airflow through the inlet region. A method, for actively changing an effective flow-through area of an inlet region of an aircraft engine, includes creating at least one region of separated, vortical flow in an airflow passage defined by the inlet region. The method further includes trapping the region of separated, vortical flow in the airflow passage. The region of separated, vortical flow partially obstructs a main inlet airflow.

Abstract: A flow control device for a combustor is provided in which the flow control device comprises a shroud having a first end and a second end wherein the second end is coupled to the combustor. The shroud is disposed to receive a primary fluid and disposed to direct the primary fluid into the combustor. In addition, the shroud further comprises a plurality of ports disposed therein wherein the ports are oriented to extract a portion of a flow from a flow path of the primary fluid so as to control a flow rate of the primary fluid through the shroud.