An airflow control system for a gas turbine according to an embodiment includes: an airflow generation system for attachment to a rotatable shaft of a gas turbine system, the airflow generation system drawing in an excess flow of air through an air intake section; a mixing area for receiving an exhaust gas stream of the gas turbine system; an air extraction system for: extracting at least a portion of the excess flow of air generated by the airflow generation system to provide bypass air; and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream; and an exhaust processing system for processing the reduced temperature exhaust gas stream.

An airflow control system for a gas turbine according to an embodiment includes: an airflow generation system for attachment to a rotatable shaft of a gas turbine system, the airflow generation system drawing in an excess flow of air through an air intake section; a mixing area for receiving an exhaust gas stream of the gas turbine system; an air extraction system for: extracting at least a portion of the excess flow of air generated by the airflow generation system to provide bypass air; and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream; and an exhaust processing system for processing the reduced temperature exhaust gas stream.

A gas turbine engine includes a cooling air system, a coolant system, and a thermoelectric heat exchanger adapted for selective operation in response to operational states of the gas turbine engine.

An apparatus and method for an engine component having a hot surface adjacent a hot combustion gas flow and a cooling surface adjacent a cooling fluid flow can include at least one dimple for enhancing the cooling along the cooling surface. The dimple can be shaped having a head and a tail with the head disposed upstream of the tail to provide for reduced dust collection along the engine component.

An apparatus and method for an engine component having a hot surface adjacent a hot combustion gas flow and a cooling surface adjacent a cooling fluid flow can include at least one dimple for enhancing the cooling along the cooling surface. The dimple can be shaped having a head and a tail with the head disposed upstream of the tail to provide for reduced dust collection along the engine component.

Gas turbine engines are described. The gas turbine engines includes a compressor section, a combustor section, a turbine section, and a nozzle section. The compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section. A cooling duct is provided that is separate from the core flow path. A waste heat recovery system is arranged with a heat rejection heat exchanger arranged within the cooling duct and a blower is arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger.

Gas turbine engines are described. The gas turbine engines includes a compressor section, a combustor section, a turbine section, and a nozzle section. The compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section. A cooling duct is provided that is separate from the core flow path. A waste heat recovery system is arranged with a heat rejection heat exchanger arranged within the cooling duct and a blower is arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger.

A gas turbine engine includes a fan located at a forward portion of the gas turbine engine, a compressor section and a turbine section arranged in serial flow order. The compressor section and the turbine section together define a core airflow path. A rotary member is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. An outlet guide vane assembly includes multiple outlet guide vanes located in an exhaust airflow path downstream of the turbine section. The multiple outlet guide vanes being spaced-apart circumferentially from each other over an angular range of about 360 degrees, and each multiple outlet guide vane defining a radial extent. At least one of the multiple outlet guide vanes includes a cold fluid passageway extending at least partially radially therethrough through which a fluid coolant flows and another of the multiple guide vanes includes a heated fluid passageway extending at least partially radially therethrough through which the fluid coolant flows and receives heat from exhaust airflow from the core airflow path.

A gas turbine engine includes a fan located at a forward portion of the gas turbine engine, a compressor section and a turbine section arranged in serial flow order. The compressor section and the turbine section together define a core airflow path. A rotary member is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. An outlet guide vane assembly includes multiple outlet guide vanes located in an exhaust airflow path downstream of the turbine section. The multiple outlet guide vanes being spaced-apart circumferentially from each other over an angular range of about 360 degrees, and each multiple outlet guide vane defining a radial extent. At least one of the multiple outlet guide vanes includes a cold fluid passageway extending at least partially radially therethrough through which a fluid coolant flows and another of the multiple guide vanes includes a heated fluid passageway extending at least partially radially therethrough through which the fluid coolant flows and receives heat from exhaust airflow from the core airflow path.

A thermal management system for transferring heat between fluids includes a thermal transport bus through which a heat exchange fluid flows. Additionally, the system includes a heat source heat exchanger arranged along the bus such that heat is added to the fluid flowing through the heat source heat exchanger. Moreover, the system includes a plurality of heat sink heat exchangers arranged along the bus such that heat is removed from the fluid flowing through the plurality of heat sink heat exchangers. Furthermore, the system includes a bypass conduit fluidly coupled to the bus such that the bypass conduit allows the fluid to bypass one of the heat source heat exchanger or one of the heat sink heat exchangers. In addition, the system includes a valve configured to control a flow of the fluid through the bypass conduit based on a pressure of the fluid within the bus.