Abstract: A submersible pump includes an impeller (8) arranged in a pump housing (2). A seal (22) seals the impeller (8) with respect to a stationary part of the pump housing (2). The seal (22) includes a sealing ring (24) arranged on the impeller side. The sealing ring engages in a second sealing ring (26) arranged on the pump housing side. The sealing ring (26) on the pump housing side has at least one hole (28) for discharging solid particles from the impeller (8).

Abstract: An exemplary air cycle machine bearing housing includes a housing establishing a bore that receives a bearing. The bearing rotatably supports an air cycle machine shaft. The bore has an axial length and a radial diameter. A ratio of the axial length to the radial diameter is from 0.6989 to 0.7128.

Abstract: A seal assembly for a bearing chamber of a gas turbine engine. The seal assembly includes a seal land having a sealing surface and a non-sealing surface, and at least one non-contact seal member having a sealing surface and a non-sealing surface. The opposing sealing surfaces define a fluid flow path for a sealing fluid such as air from a compressor of the gas turbine engine. The seal assembly includes a sealing fluid cooling arrangement comprising an oil jet configured to provide cooling oil to one or both of the seal member and the seal runner non-sealing surfaces.

Abstract: A turbocharger rotating assembly includes a bearing; a shaft and turbine wheel assembly supported by the bearing; a seal ring disposed about the shaft; and a sleeve that supports the bearing and that includes a compressor end and a turbine end, a bore extending axially from the compressor end to the turbine end, a first counter bore that forms an axial face that axially locates the bearing in the bore, a second counter bore disposed axially between the first counter bore and the turbine end wherein the second counter bore comprises a seal surface that forms a lubricant and exhaust seal with the seal ring disposed about the shaft, and a securing feature to secure the sleeve with respect to a turbocharger housing. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: A gas turbine engine includes a first non-contacting dynamic rotor seal interfaced with a spool, the first non-contacting dynamic seal operates to seal adjacent to an outer diameter and a second non-contacting dynamic rotor seal with respect to the spool, the second non-contacting dynamic seal operates to seal adjacent to an inner diameter.

Abstract: A card seal with an annular arrangement of cards that form the card seal, where the cards are interweaved and staggered to increase a sealing capability of the cards. The card seal is formed from leading edge cards staggered with trailing edge cards, and the cards have a thicker outer end and a thinner inner end where the interweaving occurs. Because of the varying thickness of the staggered cards, each card has a taper on the lower outer end that decreases from a high to a low on the inner side in order that a foot print for the card is constant across the bottom surface that floats on the rotating part.

Abstract: A turbo compressor in an axial type of construction is disclosed. The turbo compressor has a bladed stator and a bladed rotor, and has a longitudinally split compressor casing and a guide blade ring with adjustable guide blades. The guide blades are pivotably mounted about radial axes radially within their aerofoil on an inner ring belonging to the stator. The inner ring is split, i.e., segmented, at at least two points of its circumference. Furthermore, the inner ring has for each guide blade at least one bearing bush which can be inserted radially into an opening from inside.

Abstract: A sealing arrangement, for example for providing an intershaft seal between shafts of a gas turbine engine, includes an air-riding sealing ring disposed between runners. A buffer fluid, such as air, is conveyed to a buffer cavity through a passage in the sealing ring. The buffer air provides a positive pressure drop along fluid-riding gaps, preventing leakage across the sealing arrangement. The sealing ring may be a split carbon ring, and measures may be provided to minimise leakage of buffer air at the split.

Abstract: A method for servicing a gas turbine engine includes providing access from a forward section of the gas turbine engine to a gearbox contained within a bearing compartment. A gas turbine is also disclosed in which a bearing package is mounted to a front center body support and a low spool. A front wall is removable from the front center body support to provide access to the gearbox.

Abstract: A rotor blade section and a method for assembling a rotor blade for a wind turbine are disclosed. The rotor blade section includes a plurality of ribs each extending in a generally chord-wise direction. Each of the plurality of ribs includes an outer surface. The outer surface has a generally aerodynamic contour. The rotor blade section further includes at least one cross-member extending between adjacent ribs of the plurality of ribs, and an outer body mounted to the plurality of ribs. The outer body has an aerodynamic contour generally corresponding to the aerodynamic contour of the plurality of ribs.

Abstract: A seal assembly for a rotary machine is provided. The seal assembly includes multiple sealing device segments disposed intermediate to a stationary housing and a rotor. Each of the segments includes at least one plate and a sealing element. The seal assembly also includes multiple inter-segment gaps formed between the multiple sealing device segments. Further, for each pair of adjacent sealing device segments, at least one pair of adjacent plates includes one plate overlapping another plate at an inter-segment gap.

Abstract: An improved mechanical seal assembly is provided for hydro transport applications and other similar applications, such as large high pressure slurry pumps. This mechanical seal is used in large scale pumps having an axially adjustable shaft to accommodate high wear applications by maintaining suitable pump performance. The improved seal is a cartridge seal that includes a stationary seal adapter which is mounted to a pump casing and has a static gasket sealingly contacting a movable gland which non-rotatably supports the stationary seal rings of a mechanical seal. Additional seal rings are rotatably supported on the shaft wherein these rotatable and non-rotatable seal components are movable axially with the shaft to improve pump performance in high-wear conditions. The gland and non-rotatable seal rings are supported on and move with a bearing housing, along with the shaft and its seal rings.

Abstract: A thermally actuated shutdown seal for a rotating shaft having a narrow annular fluid flow path surrounding the shaft. The seal surrounds the shaft with the annulus therebetween during normal operation and constricts against the shaft when the shaft slows or stops rotating. The annulus is maintained open during normal operation by a spacer interposed between opposing ends of a split ring. When the shaft stops rotating, the temperature of the annulus rises, which actuates removal of the spacer from the split ring constricting the split ring against the shaft blocking the annulus. The blocked annulus causes a pressure differential across the seal which urges a polymer seal ring, downstream of the split ring against the shaft which seals the annulus. In one embodiment, the spacer is formed of a meltable material. In a second embodiment, the spacer is removed from the split ring by a thermally responsive actuator.

Abstract: A seal assembly for a gas turbine engine is provided that includes a seal support member, at least one knife edge seal blade member, and at least one cooling member. The seal support member is configured for rotation within the gas turbine engine around an axial centerline of the engine. The support member has a thickness extending between a first surface and a second surface. The blade member extends outwardly from the first surface of the support member. The blade member has a central portion that extends between a base end and a distal knife edge end. The base end is attached to the first surface of the seal support member. The cooling member extends outwardly from the second surface, and is oppositely aligned with the blade member.

Abstract: A sealing device includes a housing that rotatably accommodates a rotary shaft, a plurality of guide parts that extend along at least one of a radial direction and an axial direction of the rotary shaft and that impart flow velocity components in the rotation direction of the rotary shaft to fluid passing through therebetween, a partition part that connects ends of the plurality of guide parts and that serves as a partition between spaces between the plurality of guide parts and an outside space, a first seal part that is an annular protrusion extending in the radial direction, that forms a first gap with respect to the rotary shaft or the housing, and that blocks fluid flowing toward the plurality of guide parts, and a second seal part that is an annular protrusion, that forms a second gap with respect to the rotary shaft or the partition part, and that blocks fluid flowing through the outside space.

Abstract: A reverse flow tolerant brush seal arrangement for restricting the transfer of a pressurized fluid between a first and a second chamber along a moving shaft. Opposing backing plates are provided to stiffen brush bristle alignment on the moving shaft. Differential pressure between the chambers is aided by spring biasing to seat axial movement of a sliding brush seal against one of the opposing backing plates for stiffening to maintain a design clearance with a shaft being sealed.

Abstract: A bearing and seal assembly for supporting and sealing a terminating outboard end of an impeller shaft in a centrifugal pump such as a between-bearings pump includes only one seal but provides advantages typical of a dual-seal assembly, including barrier fluid protection against seal damage caused by abrasive slurries, and protection against leaking of toxic process fluid to atmosphere. A bearing housing sealed to the pump's pressure casing encloses the seal, bearing, and terminating impeller shaft end. Leakage of process fluid past the seal is prevented by a lubricating, pressurized, cooled barrier fluid which is circulated through the bearing housing by an external pump and/or by an internal, shaft-driven impeller. Because the impeller shaft terminates within the bearing housing and does not penetrate to atmosphere, the barrier fluid is contained within the bearing housing and a second seal is not required.

Abstract: A seal structure includes: first and second members defining a hollow internal area of a fluid device; and a seal member fixed to the first member for sealing a gap between the first and second members. The seal member includes a sliding contact member being in sliding contact with a surface of the second member and formed of a resin. The second member includes a resin layer and a resin layer holding structure. The resin layer is formed by sliding the second member on the sliding contact member to transfer the resin forming the sliding contact member onto a sliding contact portion of the surface of the second member at which the second member comes into contact with the sliding contact member. The resin layer holding structure is a porous film formed by electric discharge surface treatment and holds the resin layer in the sliding contact portion.

Abstract: Vacuum pump for pumping gas from a process chamber, the pump comprising: a rotor supported for rotation in a pumping chamber by a drive shaft, the shaft extending through a shaft bore in a wall of the pumping chamber extending transversely to the drive shaft, and a seal arrangement provided between the shaft and the transverse wall for resisting the passage of gas through the shaft bore, wherein on rotation of the rotor gas is pumped from a low pressure region at an inlet of the pumping chamber to a high pressure region at an outlet of the pumping chamber, and wherein the rotor and the transverse wall are spaced apart by an axial clearance along which back leakage of gas can flow from the high pressure region to the low pressure region, and an additional leakage path for back leakage is formed spaced away from the seal arrangement along which gas can flow without contact with the seal arrangement so that the amount of gas which contacts the seal arrangement during use of the pump is reduced.

Abstract: A steam turbine and a rotor are disclosed having steam extending internally along at least part of the rotor. The rotor includes an interface and a steam passage system formed in the rotor, the passage system including a first inlet flow passage to the interface, the first inlet flow passage configured to receive steam from a first region of an outer surface of the rotor, a first outlet flow passage from the interface, the first outlet flow passage configured to pass steam to a second region of the rotor, a second inlet flow passage to the interface, the second inlet flow passage configured to receive steam from a third region of the outer surface of the rotor, a second outlet flow passage from the interface, the second outlet flow passage configured to pass steam to a fourth region of the rotor.

Abstract: A labyrinth sealing ring for a labyrinth seal of a turbine disk 1 of a gas turbine includes a metallic annular element 3 with at least one annular sealing lip 4. The sealing lip 4 is provided with at least one groove 5 on its circumference which is essentially arranged in the radial direction.

Abstract: A turbine inter-stage seal with active clearance control. The inner diameter of the stator vane includes a seal support structure with a plurality of segmented seal supports each movable by an actuator located on the vane outer diameter with a plunger or push rod extending through the hollow portion of the vanes. A segmented seal arrangement, such as segmented brush seals, are secured to the underside of the seal support segments and form a complete annular seal for the inter-stage between adjacent rotor disks. A proximity probe or microwave sensor detects the brush seal clearance, and a controller regulates the brush seal clearance.

Abstract: A gas turbine engine includes a synchronizing ring. A cradle includes an integrally formed anti-rotation feature. The cradle is secured to the synchronizing ring and located relative thereto with the anti-rotation feature. A bumper is slidably supported within the cradle. In one example, a bushing is provided within a hole in the bumper. A fastener is inserted into the hole and a bushing to secure the bumper to the synchronizing ring.

Abstract: A leaf seal 10 in a rotary machine is located between a higher pressure region 14 and a lower pressure region 16 of the machine. Blow-down forces are greater on the lower pressure side 16 of the leaf seal 10 than on its higher pressure side 14, resulting in greater inward deflection of the leaves 20 on the lower pressure side of the seal than on its higher pressure side, leading in turn to greater wear of the leaves and the contacting rotor surface 44 on the lower pressure side 16 of the seal. To counteract this, the free ends 36 of the leaves 20 can be given a tapered profile 42 to gradually reduce the length of each leaf 20 over its width ‘w’ from its higher pressure side 14 to its lower pressure side 16, so that the leaves 20 are free to deflect under the blow-down forces by the amount of their reduction in length (a maximum of ‘x’), before they contact the rotor surface.

Abstract: A feather seal assembly includes a seal having a directional passage to direct an airflow generally non-perpendicular to the seal.

Abstract: An assembly for gas turbine engine includes a cross-over housing, an inter-shaft seal housing, and a linkage. The inter-shaft seal housing is disposed within the cross-over housing. The linkage is connected to the inter-shaft seal housing and extends through a slot in the cross-over housing. The linkage is removable from both the inner radial housing and the outer radial housing.

Abstract: A closure device for a casing having at least one access opening wherein the closure device includes a cover member movably disposed within an interior chamber of the casing so as to be slidably displaceable along or in the direction of a casing central axis between an open and a closed position, the cover member being spaced at least partially axially from the access opening in the open position so as to permit access to the interior chamber and generally extending across and substantially obstructing the at least one access opening in the closed position.

Abstract: A pump insert (128) has an inner surface which in use defines a portion of a volute (124) of a pump (110) wherein said pump insert (128) is adapted to be coupled with a pump casing (116) by an inter-engaging profiled coupling arrangement (166). In one disclosed embodiment the pump insert (128) is adapted to engage a pump casing closure plate (148) which is locatable about a pump shaft (112) and between the pump inert (148) and the pump casing (110).

Abstract: A stator stage of a compressor of a turbomachine including an annular row of variable-pitch vanes is disclosed. Each vane includes an external cylindrical pivot defining the axis of rotation of the vane, and an internal cylindrical pivot mounted in a housing of an internal ring. The internal pivot of each vane extends along an axis substantially parallel to the axis of rotation of the vane and at a distance from this axis, and is mounted in the housing of the ring by a swiveling or a tilting system.

Abstract: A force balanced seal for use with a rotor in the turbomachine has a member in opposed facing disposition to the rotor with a face dam portion of the member having a surface parallel with the sealing surface of the rotor, a groove in the member facing the rotor and bounding the face dam surface, an air bearing surface in the member facing the sealing surface of the rotor, a second passageway through the member from the air bearing surface to a radially outwardly facing surface of the member and a first passageway through the member from the groove to a member surface facing oppositely from the air bearing surface. An operating clearance between the seal and rotor is maintained by a closing force, exerted through a plurality of springs, and an opposing opening force created by pressurized air venting through the second passageway to the first passageway.

Abstract: An example seal shaft includes a cylindrical body establishing a bore that extends axially between a first end portion of the body and a second end portion of the body. Apertures are also established in the body. The apertures extend radially between an outer surface of the body and the bore. The seal shaft further includes a first group knife edge seals and a second group of knife edge seals. The first group of knife edge seals have a diameter, and a ratio of the diameter to the total cross-sectional area of the apertures is between 58.79 and 78.77.

Abstract: An exemplary locating mechanism for locating a turbine bearing in a bore of a housing includes a conical pin having a pin axis where the conical pin includes a conical wall portion and a pin portion to locate a turbine bearing; a ball; and a socket disposed in a housing and extending between an opening of the housing and a bore of the housing, the socket having a socket axis where the socket includes a cylindrical surface and a conical surface. According to such a mechanism, disposition of the conical pin in the socket seats the conical pin along the socket axis and against the conical surface and disposition of the ball in the socket seats the ball along the socket axis and against the cylindrical surface. Accordingly, alignment of the ball with respect to the conical pin allows for transmission of force from the ball to the conical pin along the pin axis. Various other exemplary technologies are also disclosed.

Abstract: A seal assembly for deflecting contaminated fluid flowing through the seal assembly from an upstream space to a downstream space includes an annular housing, at least one vent hole peripherally disposed on the annular housing, a first set of seals disposed within the annular housing adjacent to the downstream space, the first set of seals having an inclined surface to deflect the flow of contaminated fluid through the at least one vent hole, and a second set of seals mounted on the shaft, disposed within the annular housing, adjacent to the first set of seals and adjacent to the upstream space. The second set of seals may have larger inside diameter than the first set of seals. The seal assembly may prevent contaminated fluid from entering an air bearing cooling circuit, thereby preventing bearing wear, erosion and failure.

Abstract: Mechanical seals, seal assemblies and pumps are disclosed. A mechanical seal includes a sealing member and a mount that forms part of a mounting assembly to mount the sealing member to a support structure of the seal. In an embodiment, the mount forms part of a seal assembly and is an elastomeric ring bonded to the sealing member.

Abstract: Self-balancing face seals and gas turbine engine systems involving such seals are provided. In this regard, a representative self-balancing face seal assembly includes: a rotatable seal runner having a first seal runner face and an opposing second seal runner face; a first face seal operative to form a first seal with the first seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal; and a second face seal operative to form a second seal with the second seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal.

Abstract: In one aspect, the present disclosure is directed to a turbine engine. The engine may include a main housing defining a compressor compartment and an air intake housing mounted to the main housing. The engine may also include a rotor including a compressor portion disposed within the compressor compartment, and a hub portion extending from the compressor compartment through an opening in the air intake housing into a bearing compartment defined by the air intake housing. The engine may further include a seal mounted in the opening in the air intake housing in an annular gap between the hub portion of the rotor and the air intake housing and configured to form a seal between the bearing compartment and the compressor compartment. The seal may be configured to be removed from the opening in the air intake housing while the air intake housing is mounted to the main housing.

Abstract: A seal for a gas turbine engine component having an airfoil with a radial outward end and a radial inward end, one of which is bare metal. A seal member is adjacent to the bare metal end of the airfoil wherein the seal member is coated with a abrasive layer having a laser engraved surface with the top of the surface has less than about 5% of the surface area of the base of the abrasive layer.

Abstract: A multistage turbocompressor is provided for compressing a process gas. The turbocompressor has includes a rotor and a casing. A gas seal is associated in each case with a first turbocompressor stage and a last turbocompressor stage for sealing a penetration of a rotor shaft through a wall of the at least one casing, against a respective stage inlet pressure or stage discharge pressure. The gas seals are connected to a sealing gas line via which they are supplied with a sealing gas. A pressure chamber on a pressure side of the gas seal of the last stage which provides sealing against pressure discharge to the environment is connected to a relief line which opens into a pressure sink. A plurality of sealing gas lines are connected to a sealing gas feed line in which at least one control valve is arranged between junctions of different sealing gas lines.

Abstract: A turbomachine, particularly a steam turbine, is provided.

Abstract: A variable vane assembly for a gas turbine engine is disclosed herein. The variable vane assembly includes a vane operable to pivot about a pivot axis. The vane includes a flap portion positionable in a fluid stream for controlling a flow of fluid. The vane also includes a stem portion for mounting the flap portion. The vane also includes a button portion positioned between the flap portion and the stem portion along the pivot axis. The button portion is wider than the stem portion in at least one plane containing the pivot axis. The variable vane assembly also includes a bushing encircling the stem portion and abutting the button portion. The variable vane assembly also includes a labyrinth seal positioned between the bushing and the button portion.

Abstract: A standard for supporting a bearing for a rotating shaft of a machine including a plurality of casings having different gas pressures greater than atmospheric pressure includes a sealed chamber for fluidly coupling to an end packing of a first casing and a second casing of the machine, the sealed chamber having a pressure greater than atmospheric pressure. The pressure in the sealed chamber reduces the leakage from the casing making more pressurized gas available for producing work in the machine.

Abstract: A system, in certain embodiments, includes a seal assembly having a seal body. The seal body includes an inlet buffer port and an outlet eduction port. The inlet buffer port is configured to receive a compressed buffer gas, such as shop air, which is injected into the inlet buffer port. The compressed buffer gas blocks the flow of a compressed process gas, such as land fill gas, by opposing the flow of the compressed process gas through the seal assembly. Both the compressed buffer gas and the compressed process gas may be expelled through the outlet eduction port.

Abstract: A central tubular structure of a shaft seat and a fan device thereof. The central tubular structure includes a base, a bushing connected with the base and a sealing member. The bushing has an outer tubular wall, an inner tubular wall and a top section interconnected between the outer and inner tubular walls to define a receiving space. The inner tubular wall defines a bearing hole. The bushing further has a reception space in adjacency to the base in communication with the receiving space and the bearing hole. The sealing member is fitted in the reception space to seal the same. The fan device is composed of the central tubular structure, a stator assembly, at least one bearing and a fan propeller. The stator assembly is arranged in the receiving space and has a substrate board. The substrate board is free from any perforation and received in the reception space.

Abstract: A bearing arrangement for a turbine rotor of a turbine is adapted to be mounted in a drill string and to be driven by the flow of drilling fluid. The bearing arrangement includes a turbine chamber surrounding the turbine rotor and having an inflow and an outflow, a stator on which the turbine rotor is rotatably mounted, and a cavity formed between the turbine rotor and the stator and accommodating at least one radial plain bearing and being separated from the turbine chamber by an axial plain bearing constructed as a bearing ring seal and by a conveyor screw which is disposed on the turbine rotor and operates to convey from the cavity to the turbine chamber.

Abstract: In accordance with one embodiment, a system includes a multi-stage turbine including a first turbine stage including a first wheel having multiple first slots spaced circumferentially about the first wheel, and multiple first blade segments each coupled to at least one of the multiple first slots. The multi-stage turbine also includes a second turbine stage including a second wheel having multiple second slots spaced circumferentially about the second wheel, and multiple second blade segments each coupled to at least one of the multiple second slots. The multi-stage turbine further includes a one-piece interstage seal extending axially between the first and second turbine stages, wherein the one-piece interstage seal comprises a first radial support coupled to the first wheel and a second radial support coupled to the second wheel, and the one-piece interstage seal extends circumferentially across at least two of the multiple first slots or at least two of the multiple second slots.

Abstract: A shaft-sealing device includes an outer ring for receiving a shaft sleeve to rotate therewith. A magnetic-field generating unit is mounted the around rotary shaft and includes inner and outer magnetic rings. The outer magnetic ring is mounted in the outer ring. A gap is defined between an inner periphery of the outer magnetic ring and an outer periphery of the inner magnetic ring and is filled with a magnetic liquid. One or both of the inner and outer magnetic rings provide magnetic force to retain the magnetic liquid in the gap. A seal ring is mounted between the outer magnetic ring and an end of the outer ring. A lip extends from an inner periphery of the seal ring toward or away from the end of the outer ring and is at a non-parallel angle to a radial direction of the seal ring to form a seal around the rotary shaft.

Abstract: A seal gas recovery method including introducing a first seal gas stream to a first mechanically coupled booster/expander assembly, where the first booster/expander assembly includes a first booster, a first expander, a first shaft that mechanically couples the first booster and the first expander, and a first seal on the first shaft. The method further includes removing at least a portion of a first recoverable gas stream from the first seal, where the first recoverable gas stream includes at least a portion of a first process leak gas stream and at least a portion of a first seal gas vent stream. The method further includes introducing a second seal gas stream to a second expander assembly, where the expander assembly includes a second expander, a second shaft, and a second seal on the second shaft.

Abstract: The invention relates to a turbocharger (15) comprising a bearing housing (7) which mounts a rotor shaft (12) and has a bearing-housing oil space (13); comprising a compressor housing which is connected to the bearing housing (7) and has a compressor space (14); and comprising a sealing device (20) which is provided for sealing the bearing-housing oil space (13) relative to the compressor space (14) and which has a sealing ring (1) which is arranged in a fixed position in the bearing housing (7) and has two end faces (17, 17?) which interact with associated end faces (10) and (11) of a disc (9) and a sealing bush (16) which are fastened to the rotor shaft (12), wherein the sealing ring (1) is arranged with axial play on the rotor shaft (12) between the disc (9) and the sealing bush (16); and air-delivery devices (2, 3) oriented in opposition are arranged in the end faces (17, 17?) of the sealing ring (1).

Abstract: The invention regards a turbine for the expansion of gas and vapour that comprises a body or casing with a volute for the transit of the fluid from an input to an output passage through at least a statoric and a rotoric group, a possible front shield that extends radially from said volute towards the axis of the turbine shaft, an external tube member fixed in front of said shield or said volute designed to hold the turbine shaft with the interposition of a supporting unit (19), where said turbine shaft (15) has a head (15?) supporting the rotoric group (16, 17). The turbine shaft (15) together with the rotoric group (16, 17) is movable axially between a work position, in which the head of said shaft is at a distance from an internal end of the external tube member (18) facing towards the statoric group, and a retracted position, in which the head of the shaft or a part of the rotoric group rests against said internal end of said tube member with the interposition of at least a front seal (41).

Abstract: A turbomachine is disclosed that has a main fluid flowpath extending axially along the turbomachine with a rotating shaft partly enclosed in a casing, wherein the rotating shaft and casing are moveable relative to each other and define a clearance opening about the rotating shaft, whereby the main fluid flowpath fluidly communicates with an outside region, and an annular seal body defining a fluid passage having a primary fluid inlet configured to receive a pressurized fluid, a fluid outlet disposed proximate to the clearance opening, and a convergent chamber interposed therebetween, wherein the convergent chamber is configured to accelerate the pressurized fluid out of the fluid outlet so as to create a local reduced pressure at the clearance opening.