A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a shaft, a first bearing structure and a second bearing structure that support the shaft. Each of the first bearing structure and the second bearing structure includes a bearing compartment that contains a lubricant and a seal that contains the lubricant within the bearing compartments. A buffer system is configured to pressurize the seals to prevent the lubricant from escaping the bearing compartments. The buffer system includes a first circuit configured to supply a first buffer supply air to the first bearing structure, a second circuit configured to supply a second buffer supply air to the second bearing structure, and a controller configured to select between at least two bleed air supplies to communicate the first buffer supply air and the second buffer supply air.

A ventilation system includes a cavity, a fluid motive force device, and a motive fluid supply system. The cavity includes different ventilation level requirements for a plurality of modes of operation. The fluid motive force device includes a suction port, an outlet port, and a motive fluid inlet port. The suction port is coupled in flow communication with the cavity to be vented. A flow supply to the motive fluid inlet port determines a ventilation flow through the suction port. The motive fluid supply system is coupled in flow communication with the motive fluid inlet port. An operation of the motive fluid supply system determines a flow of motive fluid from the motive fluid supply system to the motive fluid inlet port. The flow of motive fluid to the motive fluid inlet port generates a ventilation flow through the suction port approximately matching a current ventilation demand of said cavity.

A cooling structure for a turbine is configured such that: a plurality of disks rotating integrally with blades are arranged along a rotational axis; and the disks have formed therein disk holes arranged in a circumferential direction to supply cooling air for cooling the rotor blades to downstream disks. At least one of the disk holes is set such that, when the rotational direction of the disk is defined as the positive direction and the direction opposite the rotational direction is defined as the negative direction, an outlet absolute circumferential velocity vector which is a component in a rotational direction U of the velocity vector of the cooling air at an outlet of a disk hole is smaller than an inlet absolute circumferential velocity vector which is a component in the rotational direction of the velocity vector of the cooling air at an inlet of the disk hole.

A combustor and a gas turbine including the same which can reduce a loss of pressure and enhance a cooling efficiency of a liner and transition piece are provided. The combustor may include a liner configured to define a combustion chamber, a transition piece coupled to a rear end of the liner, a flow sleeve configured to surround the liner and the transition piece, a plurality of impingement holes formed in the flow sleeve, and a plurality of inserts inserted into at least some of the impingement holes, wherein each of the inserts may include a first channel configured to guide combustion air, introduced into an associated one of the impingement holes, in a direction parallel to a direction of extension of an annular passage between the flow sleeve and the liner or an annular passage between the flow sleeve and the transition piece, and a second channel configured to guide the combustion air, introduced into the associated one of the impingement holes, in a direction transverse to the annular passage between the flow sleeve and the liner or the annular passage between the flow sleeve and the transition piece.

An electric submersible pump assembly. The electric submersible pump assembly comprises an electric submersible pump comprising a pump intake and a tubing configured to provide continuous fluid communication between a discharge side of the electric submersible pump and the pump intake.

Systems and methods for delivering a buffer fluid to a shaft seal of a gas turbine engine are provided. An exemplary system includes, a buffer fluid source, one or more first conduits providing fluid communication between the buffer fluid source and the shaft seal along a first route, and one or more second conduits providing fluid communication between the buffer fluid source and the shaft seal along a second route different from the first route. A heat exchanger is also disposed along the first route to facilitate heat transfer between buffer fluid in the one or more first conduits and a cooling fluid.

A heat transfer system includes a heat exchanger located at least partially within a coolant flowpath. The heat exchanger defines at least in part a first flowpath and a second flowpath, the first flowpath configured to be in fluid communication with the coolant flowpath, and the second flowpath configured to receive a flow of a motive fluid. The heat transfer system further includes a throttling device that is in fluid communication with the second flowpath of the heat exchanger. The heat exchanger receives at least a portion of the flow of the motive fluid from the heat exchanger. The throttling device is also in fluid communication with the coolant flowpath at a location upstream of the heat exchanger for providing the flow of motive fluid to the coolant flowpath at the location upstream of the heat exchanger.

A gas compressor comprising a drum affixed to a rotating shaft, the drum including a plurality of compression channels between a common pressure zone and an interior surface of the drum distal to an axis of rotation. A static vane return assembly adjacent the compression channels includes vanes extending from an inlet at an outer circumference to the common pressure zone and directing gas into the common pressure zone, either through the vanes or via separate channels or ducts. Fluid inside the rotating dmm forms an annular lake that is drawn through the vanes and into the common pressure zone. Fluid is then forced into the compression channels where gas in the fluid is compressed as it travels from the common pressure zone toward the interior surface. The pressurized gas is separated from the liquid prior to leaving the compression channel assembly while the liquid is returned to the lake.

A gas compressor comprising a drum affixed to a rotating shaft, the drum including a plurality of compression channels between a common pressure zone and an interior surface of the drum distal to an axis of rotation. A static vane return assembly adjacent the compression channels includes vanes extending from an inlet at an outer circumference to the common pressure zone and directing gas into the common pressure zone, either through the vanes or via separate channels or ducts. Fluid inside the rotating drum forms an annular lake that is drawn through the vanes and into the common pressure zone. Fluid is then forced into the compression channels where gas in the fluid is compressed as it travels from the common pressure zone toward the interior surface. The pressurized gas is separated from the liquid prior to leaving the compression channel assembly while the liquid is returned to the lake.

An igniting device for igniting a mixture, in particular for an engine, comprises an energy converting device and a fluid flow injecting device. The energy converting device is configured for converting fluid flow energy of at least one fluid flow into heat, thereby igniting the mixture. The energy converting device comprises an ignition chamber for the at least one fluid flow. The fluid injecting device is configured for injecting a plurality of fluid flows into the ignition chamber. The injection takes place such that a first fluid flow is injected into the ignition chamber with a higher fluid flow velocity than a second fluid flow.