JPH07503298A - Coolable outer air seal device for turbines - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Coolable outer air seal device for turbines, which has just been abandoned 19 Application for partial continuation application with application number 07/980,815 filed on November 24, 1992 It is a record.

Technical field TECHNICAL FIELD This invention relates to turbomachinery, and more particularly to outer air systems used in turbines. Regarding the tool equipment.

Background of the invention Typical turbomachines, such as axial flow gas turbine engines, result in An annular flow path for directing the working fluid through the engine, combustion and turbine sections. have. The compressor section consists of a number of rotating brakes that provide energy to the working fluid. contains the code. Working fluid exits the compressor section and enters the combustion section. fuel is Mixed with compressed working fluid, the mixture adds more energy to the working fluid. It is ignited in order to The combustion products then expand through the turbine section. Tar The bin section contains a number of other rotating blades that derive energy from the expanding fluid. There is. A part of the energy obtained here is distributed to the compressor and turbine parts. is returned to the compressor section via the rotor shaft connecting the energy obtained The rest of the money will be used for other functions.

The operating power of a gas turbine engine depends on many factors. Among these elements contains the heat generated during the combustion process. Calorific value depends on the fuel used and fuel/air however, it is controlled by the temperature allowed in the turbine section. limited. In modern gas turbine engines, the melting temperature of the turbine material Excessive working fluid temperature may cause cooling fluid to be directed into the turbine section. has been achieved. Typically, this cooling fluid exits the compressor section and enters the combustion section. contains a portion of the working fluid that is bypassed.

Another factor related to operating power is the combustion products and turbine rotor blades. is the energy conversion efficiency between The turbine section is located above each array of rotor blades. Orient the working fluid as much as possible before it engages the rotor blades. Contains an array of aerodynamically shaped vanes for efficient utilization. turbine Rotor blades are aerodynamically shaped to efficiently engage the working fluid It has an airfoil section. Rotor blades provide a radially inner flow surface The turbine section provides a radially outer flow surface. Contains an outer air seal device for The combination of these two flow surfaces is called rotab Restricts the flow of working fluid toward the airfoil portion of the blade.

The outer air seal device extends around the longitudinal axis of the gas turbine engine. Typically includes a plurality of arcuate sections arranged to form an annular structure Ru. An array of rotor blades rotates within one area of the outer air seal device. . Each rotor blade includes a radial outer tip that During rotation of the motor assembly, in close proximity to the outer air seal device in the close radiating section, Or touch and pass.

Contact between the tip of the blade and the flow surface of the outer air seal device Occurs due to the proximity required to restrict the flow of working fluid to the Maybe. To avoid damage to the rotor blades during contact, The tip of the board is coated with an abrasive material, and the outer air seal device is coated with an abrasive material. It has a layer of abradable material covering the flow surface.

Therefore, as the chips pass over the flow surface, any contact can cause the blades to wear out. Particles of abradable material are removed rather than damaged or damaged. The result will be

The outer air seal device segment is exposed to hot working fluid. Typically, Segments are cooled to avoid overheating of the substrate material . Cooling fluid passes radially inward through the stator assembly and into the substretch. flow on the radially outer surface of the seat. This cooling fluid is then applied to the neighboring segments. It flows radially inward between the holes and flows out into the flow path.

One type of abradable coating used in outer air seal equipment The tap is made of ceramic material. Ceramic materials are found in turbines. It is useful because of its ability to withstand high temperatures such as

Unfortunately, having two materials with different rates of thermal expansion when exposed to very hot environments Due to thermal stresses caused by There are difficulties in combining and combining rates. This is the first stage of the turbine A special truth is that the first stage of the turbine has the highest temperature working fluid. Ceramic coating from cracking and substrate exposed to leading to peeling of the ring.

Notwithstanding the above-mentioned technology, the scientists and engineers under the direction of the application assignee Cracking and/or delamination of the abradable layer from the knot segment is the most I am working to develop a small outer air seal device.

Disclosure of invention According to the present invention, an outer air seal device includes a plurality of segments having a substrate. impingement material for cooling the abradable layer and substrate. and a cooling fluid buffer for flowing a cooling fluid buffer over the abradable layer. film cooling means.

Furthermore, according to the invention, the impingement cooling means are located radially outwardly. a cover plate defining a cavity therebetween and having a plurality of openings; I'm here. The cooling fluid flows through the opening and the substrate facing the cavity. impact on the surface.

Furthermore, the film cooling means passes through the substrate and the abradable layer. Corner to stretch out and squirt a film of fluid onto the surface of the abradable layer Contains multiple graded cooling holes. This cooling hole allows the blade chip to pass through. It is aligned with the direction of blade passage to eject cooling fluid in the same direction as the blade. .

According to a special embodiment, the outer air seal segment A pair of cavities spaced apart on an axis extending between the bars. means for generating a differential pressure; the first cavity has a second cavity; the cover has a first and second plurality of openings; 1st gear The bitty is in communication with a source of cooling fluid through the first plurality of openings. 2nd cabinet The tee is downstream of the first cavity and passes the same cooling through a second plurality of openings. in communication with a source of cooling fluid. In this particular embodiment, the means for providing a pressure difference the first plurality of openings having a diameter D1 greater than the diameter D2 of the second plurality of openings; Defined by mouth. Cooling fluid is substrate and abradable ceramic The key passes through the cooling holes extending through the ink layer and through the ink segment holes. leaks into the cavity. The cooling holes are angled about the radial axis and It has a flared portion that spreads a film of cooling fluid over the braidable layer. this The cooling holes are aligned with the blade passing direction to eject fluid in the blade tip passing direction. It's in a straight line horizontally. Ink segment holes allow convection cooling of segments, adjacent Provide impingement cooling of the segment, and ink segment space Inject cooling fluid into the surrounding space between adjacent segments to purge the working fluid. put out

Due to structural reasons, the air seal segment was extended as the upstream terminal part Where the end section is included, the cavity adjacent thereto is connected to the expanded terminal section. It may include longitudinally extending chambers arranged therein.

This chamber allows cooling fluid to pass through the terminal section for improved cooling. has the added benefit of providing stress relief in

The main features of the invention are the impingement cooling means and the outer air seal segment. It is a combination of film cooling means. Another feature is the blade passage. Along with the direction is the alignment of the cooling holes. Special embodiment features include impingement force A pair of cavities defined by a cavity and a substrate. special fruit Another feature of the embodiment is the means to generate different pressures between the cavities. . Further features are the angle and shape of the cooling holes. A further feature is the segment The ink segments and holes are located along the lateral edges of the sheet.

An advantage of the present invention is that the segmentation as a result of impingement cooling and film cooling is level of thermal stress inside the component. Impingement cooling cools the substrate Maintain the temperature within the allowable temperature range of the substrate material.

Film cooling consists of an abradable layer and an action to cool this abradable layer. A cooling fluid buffer zone is created between the cooling fluid and the dynamic fluid. The two cooling means are combined , an abradable material layer and a substratum to minimize thermal stress between the two material layers. Minimize the temperature gradient between the Another advantage is that the radial axis The result is that the holes are angled with respect to the blade passage direction and the cooling holes are aligned in a straight line. As a result, there is an expected useful life of the segment. Angling the cooling holes is the grain exposed as a result of abrasive contact between the blade tip and the segment. Widen the aperture of the abradable layer to reduce the possibility of children blocking the cooling holes.

Placing the cooling hole in line with the direction of blade passage means that removed particles can block the cooling hole. Further reduces the possibility of detection. Advantages of special embodiments include multiple cavities and pressure As a result of the means to differentiate the This is the effectiveness of film cooling. Another advantage of the special embodiment is that the ink segment thermal stress levels near the lateral edges of the segment as a result of component cooling. . Ink segment cooling holes segment convection cooling and inbingement cooling bring to the lateral edge. Furthermore, the cooling that is flowing into the ink segment area The cooling fluid is placed in this area to prevent the uptake of hot working fluid between adjacent segments. wipe out.

The foregoing and other objects, features and advantages of the invention will be apparent from the exemplary embodiments illustrated in the accompanying drawings. It will become clearer with reference to the detailed description below of the example.

Brief description of the drawing FIG. 1 is a side cross-sectional view of a gas turbine engine.

Figure 2 shows the outer air seal device, turbine rotor device, and upstream and downstream bases. FIG.

FIG. 3 is a view of the radially outer surface of a single outer air seal segment.

FIG. 4 is a view of the radially inner surface of the non-glue outer air seal segment.

FIG. 5 is a partial cross-sectional view taken along line 5-5 in FIG.

Figure 6 shows the outer air nord segments with arrows indicating the flow direction of the film cooling. FIG.

7a is a cross-sectional view of the film cooling hole along line 7-7 of FIG. 5. FIG.

Figure 7b shows the film cooling holes after the removed abradable particles have aggregated. It is a diagram.

FIG. 8 is a side view, partially in section, similar to FIG. 5, but showing another embodiment of the invention; .

Best Mode for Accomplishing the Invention Depicted in Figure 1 is an axial gas turbine shown as an example of a typical turbomachinery. This is the engine 12.

This gas turbine engine includes an axial flow path 14, a compressor 16, and a combustor 1. 8 and includes a turbine 22. The compressor extends through the flow path and and includes a plurality of compressor blades 24 that engage the working fluid within the flow path. . The engagement between the working fluid and the compressor rotor blades imparts energy to the working fluid. Move. The working fluid flows out into the compressor and it is mixed with the fuel supply Enter the combustor. The mixture is fed into the combustor to add more energy to the working fluid. It is ignited inside. The products of combustion then pass through a turbine and expand. this The turbine includes a plurality of on-axis turbine vanes 26 and turbine rotor blades 28. contains alternating stages. The turbine rotor blades extend through the flow path and engages the working fluid to transfer energy from the working fluid to the turbine rotor blades. do. Some of this energy transferred to the turbine rotor blades is to the compressor section via a pair of rotor shafts 32 that connect it to the compressor. be transferred.

As shown in FIG. 2, each stage of the turbine rotor blade 28 This is the downstream side of the stage of the turn 26 in the axial direction. Each turbine rotor blade is including a foil portion 34 having a radially disposed radial tip therein. 36 and a platform 38. The platform includes a flow surface 42 , its face facing radially outward toward the flow path.

This platform flow surface allows the working fluid in the flow path to flow radially inward. I'm going to do something.

The radially outwardly facing airfoil tip is the outer air seal device 44 . child 7. The outer air seal device seals the air around the turbine rotor blades for a certain distance in the circumferential direction. It includes a plurality of spaced apart segments 46. Multiple segments have their surfaces in the flow path. It defines an annulus having a radially inwardly directed flow surface 52 . This air seal flow The face is radially proximate to the airfoil tip and the working fluid is directed radially outward. to get in the way of the flow.

The segments are depicted in more detail in Figures 3-6.

Each segment includes a substrate 54, an impingement cover 56, and an A braidable material layer 58 is included. The substrate is used to hold each segment. It includes a plurality of hooks 62 for engaging the stator mechanism 64 for purposes of engagement. Ceramic material is was proposed as an abradable layer due to its insulating properties, but non-ceramic materials are also It may be applicable.

An impingement cover is disposed on the outwardly facing side of the substrate.

This impingement cover and substrate are connected to the first cavity 66 and this A second cavity 68 is defined axially upstream and downstream of the first cavity. This i The impingement cover is in the first position, as shown more clearly in FIGS. a plurality of impingement holes 72 and a second plurality of impingement holes 7 Contains 4. The first plurality of impingement holes are connected to the first cavity. Provides communication with a source of cooling fluid. The second plurality of impingement holes are Provides communication between the second cavity and a source of cooling fluid.

The segment has a lid that has a higher pressure in the first cavity than in the second cavity. and means for creating a pressure differential between the two cavities. As shown in Figure 4, This means is defined by having impingement holes of different diameters. Ru. The first plurality of cooling holes each have a diameter. The second plurality of cooling holes each have a diameter D2, where D2 is smaller. Larger diameter cooling holes are the first Allows greater cooling fluid flow into the cavity. Fills with approximately the same number of cavities impingement cooling holes and because they are approximately the same size. The difference in hole diameter creates a higher pressure in the first cavity. like this Although described and shown in Other means for generating different pressures are used, such as the more pronounced properties of It might happen.

A plurality of film cooling holes 76 are provided between the substrate and the substrate, as shown in FIGS. 3 and 5. It extends through the braidable layer. The first plurality of film cooling holes 78 are It extends between the cavity and the flow path. The second plurality of film cooling holes 82 are It extends between the second cavity and the flow path. The film cooling holes allow the cooling fluid to Abradab to provide the best coverage taking into account engine efficiency losses. are closely spaced over the entire surface of the layer. film cooling hole The large area covered by the abradable layer results in a large area covering most of the This results in a uniform film of cooling fluid.

Each film cooling hole is shaped and oriented as shown in FIG. each The film cooling hole includes a uniform diameter section 84 and a flared section 86. flare The part opens to the flow surface and diffuses the cooling fluid flowing through the film cooling holes. bring about. By diffusing the cooling fluid before releasing it onto the flow surface , the area of the cooling fluid increases and the speed of exit from the film cooling holes is reduced. Ru. The increase in the area of ejected fluid also means that each film cooling hole Increase coverage provided on the surface. Cooling fluid released from film cooling holes Reducing the velocity of the fluid helps the ejected fluid stick to the flow surface. .

Each of the film cooling holes is arranged with respect to a radial axis 88 of the gas turbine engine. It is inclined at an angle α.

As a result of the slanted holes, there is an elliptical opening in the flow plane of the abradable layer. It is formed. The oval aperture is a source of particles that adhere to the aperture due to the flow on the flow surface. Less likely to cause blockage. Additionally, cooling holes that are inclined with respect to the radial axis are To further encourage the growth of the cooling fluid film, the flow surface is Discharge cooling fluid tangentially upward.

The majority of the film cooling holes are aligned with the direction of blade passage indicated by arrow 92 and cooling. The direction of fluid discharge is oriented in a straight line in the lateral direction. -Draw a straight line The resulting cooling holes are similar to film cooling holes when the abradable layer is removed. It becomes blocked by particles.

Each segment includes a plurality of ink segment cooling holes 94. this ink Segment cooling holes define lateral spaces 96 between the cavities and adjacent segments. It brings about circulation between. Cooling fluid is supplied to the sample in the area of the ink segment cooling holes. Flows through the ink segment holes to provide convective cooling of the blast rate .

Cooling fluid exiting the ink segment cooling holes (indicated by arrows 98) flows into the adjacent segment cooling fluid. collision with the ridge 102 of the lateral edge of the component. After a collision occurs, the cooling flow The body further flows radially inwardly between adjacent segments and out into the channel. stomach The flow of cooling fluid into the link segment space works as it clears the space. Provides a means to prevent ingestion of fluid into the ink segment space.

During operation, hot working fluid passes over the flow face of the outer air seal and into the outer air seal. Heat the roll equipment. The cooling fluid flows through the radially outer spindle of the impingement force bar. Flows radially inward toward the pace. This cooling fluid is It passes through the cooling hole and flows into the cavity. Larger impingement cooling holes As a result, the internal pressure in the first cavity is greater than the internal pressure in the second cavity. Kya The cooling fluid in the segment then passes through the film cooling holes and Flow into the film cooling holes to form a film or buffer zone of cooling fluid on the flow surface. put out The pressure on the abradable layer due to the working fluid is It is largest at the edge and becomes smaller towards the downstream edge of the abradable layer. Segme Having segmented cavities at regular intervals on the axis within the , it requires high pressure cooling fluid flow through the upstream film cooling hole and the downstream and providing a means for having a low pressure cooling fluid flow through the hole. This means that that an adequate film cooling fluid supply is provided over the axial extent of the flow plane. Assure. Some of the cooling fluid within the cavity provides convective cooling to the segment. provides impingement cooling to adjacent segments, and ink segments flow into the ink segment cooling holes to purge hot working fluid from the ink segment space. It will be done.

The abrasive contact between the airfoil tip and the abradable layer This will result in the removal of particles in the Le layer. These particles 104 are film cooled It may stick inside the holes and consequently reduce the flow area of the film cooling holes.

However, as shown in Figures 7a and 7b, the angle, direction, and The radially oriented shape makes this situation less likely to occur than cooling holes of the same diameter.

Because the cooling holes are co-linear with the direction of blade passage, and because the cooling holes are radial Due to the angle with respect to the axis, the effective cooling diameter is maximized. This effect The effect is to minimize the possibility of dislodged particles clogging the film cooling holes. moreover , resulting from the angle of the film cooling holes with respect to the flared section and the radial axis. Larger openings also allow the film cooling holes to become completely obstructed or stuffed. reduce one's ability. Reducing the possibility of film cooling holes becoming blocked is the abrader Even after some degradation of the bull layer, the cooling fluid provides cooling of the segment. by ensuring that the film will continue to flow through the cooling holes. increases the expected lifespan of the component.

Referring to FIG. 8, another embodiment of the seal segment 46 is shown. to this Due to individual construction reasons that do not require a clear purpose for the The segment is located at the downstream end of the segment and has a hook similar to the hook 62 described above. The upstream end 108 includes a flared upstream end 108 having a hook 110 therein. hook 62 Similarly, the hook 110 is attached to the stator mechanism for mechanical retention of the seal segment. It is caught in the groove of 64. For the purpose of cooling the flared end 108, First cavity 66 includes a chamber 112 extending longitudinally into end 108. ing. Chamber 112 is configured to convey cooling air from cavity 66 to end 108. It functions as a passageway. Such provision of cooling air within the end portion 108 hook 110 (and the adjacent strip). The extreme heat flowing past the abradable ceramic material 58 of the It will be appreciated that this will increase thermal isolation from dirty working fluids. child Reducing thermal stress at the end 108 increases the reliability and performance of the seal and its The end 10 is increased due to the cavity defined therein by the chamber 112. This is achieved through 8 degrees of flexibility. This increased flexibility and The reduction in thermal and thermal stresses ultimately results in improved gas turbine engine performance. Minimize sole distortion (maximize seal concentricity). Seal depicted in Figure 2-7 The cooling configuration illustrated and described for the segment is similar to the seal segment depicted in FIG. Equally suitable for men.

FIG.2 Continuation of front page (81) Designated countries EP (AT, BE, CH, DE.

DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE) , J.P. (72) Inventor: Daniel Kane, United States of America, Connecticut 060 84 Toland Mile Hill Road 92 (72) Inventor Murdoch James Earl Mape, Tolland, Connecticut 06084, United States Lewood Drive 25 (72) Inventor Deer Burger James Neame Old Blackman, Hebron, Connecticut, United States 06248 code

Claims (1)

[Claims] 1 turbomachine (12) has a flow path (14) and a longitudinal axis of the turbomachine (12). a rotor blade arrangement rotatable about the rotor; and a cooling fluid source. The blade arrangement includes a plurality of radially outwardly directed tips (36) and a rotor blade arrangement. an outer air seal device (44) disposed radially outwardly of the The outer air seal device for the machine (12) is aligned with the rotor blade device on the shaft. forming a linear ring and defining a radially outer flow surface (52) of the channel (14). A plurality of arc-shaped segments (46) maintained at regular intervals on the circumference defining The segment is a substrate containing means for retaining the segment ( 54), which is disposed radially outward of the substrate (54) and is in-pin. including a plurality of apertures (72) extending radially through the jacket (56). impingement cover (56) and impingement cover (56) and the substrate (54). 6) and a substrate (5) for forming a radially outwardly directed flow surface (52). 4) a radially inner layer of abradable material (58); including a radial tip (36) and a radially adjacent flow surface (52); The opening (72) therein allows the cooling fluid passing through the opening (72) to pass through the substratum. Flow is provided between the cavity (66) and the cooling fluid source so as to impinge on the cooling fluid source (54). The substrate (54) and the abradable layer (58) are brought into contact with the first cavity. A plurality of cooling holes (76) allowing communication between the tee (66) and the flow path (14) are provided. The cooling hole (76) has an outlet in the abradable layer (58) and the cooling hole (76) has an outlet in the abradable layer (58). The holes (76) allow the cooling fluid flowing out into the cooling holes (76) to flow onto the flow surface (52). radius of the turbomachine (12) so that it can be pushed to form a body film. An outer air seal device (44 ). Two cooling holes (76) control the movement of the rotor blade (28) with respect to the segment (46). The outer air seal device according to claim 1, 8, 9 or 10, which is aligned with the direction. (44). 3 each cooling hole (76) has a downstream end and includes a flared portion (86) at the downstream end; , this flared portion (86) diffuses the cooling fluid passing through the cooling holes (76). , an outer air seal device (44) according to claim 1, 2, 7, 8, 9 or 10. 4 Furthermore, a plurality of interfaces arranged along the lateral edges of the segment (46) It includes segment cooling holes (94), the intersegment cooling holes (94) the lateral space (96) between the cavity (66) and the adjacent segment (46); The intersegment cooling holes (94) provide flow between the segments. (46) to provide convective cooling at the lateral edges, in which intersegment cooling Cooling holes (94) direct cooling fluid into adjacent segments (101). Provides impingement cooling of the lateral edges of the segment (101) and The cooling fluid flowing therein to the impingement cooling hole (94) is so that the lateral spaces (96) between the segments (46, 101) are cleared; Claim 1, 2, 3, 7, 8, 9 or 1 flowing between the segments (46, 101) The outer air seal device described in 0. 5 cover (56) and the substrate (54). 8), the second cavity (68) being connected to the first cavity (66). Downstream, a second plurality of openings (74) extend through the cover (56) to open a second key. providing communication between the cavity (68) and the source of cooling fluid; (66) and the second cavity (68). Outer air seal device (44) according to claim 1, 2, 3, 4, 7, 8, 9 or 10 . 6. The pressure difference generating means includes each of the first plurality of openings (72) having a diameter D1 and each of the first plurality of openings (72) having a diameter D2. a plurality of openings (74) of the first cavity (66); D1>D2 so that the internal pressure is greater than the internal pressure of the second cavity (68). The outer air seal device according to claim 5. 7 turbomachine (12) with a flow path (14) and a longitudinal axis of the turbomachine (12). a rotor blade arrangement rotatable about the rotor; and a cooling fluid source. The blade arrangement includes a plurality of radially outwardly directed tips (36) and a rotor blade arrangement. an outer air seal device (44) disposed radially outwardly of the The outer air seal device for the machine (12) is aligned with the rotor blade device on the shaft. forming a linear ring and defining a radially outer flow surface (52) of the channel (14). A plurality of arc-shaped segments (46) maintained at regular intervals on the circumference defining the segment has at least one flared end (108); The impingement cover is located radially outward of the substrate (54). - (56) and further includes means for retaining the impingement cover (56). ) a plurality of apertures (72) extending radially through the substrate; , due to the separation between the impingement cover (56) and the substrate (54). a longitudinally extending chamber (11 2) and a substrate (54) for forming a radially outer flow surface (52). ) and a radially inner abradable material layer (58) therein. includes an al tip (36) and a radially adjacent flow surface (52); The opening (72) in the opening (72) allows the cooling fluid that has passed through the opening (72) to pass through the substrate ( 54) providing communication between the cavity (66) and the cooling fluid source to impinge on the The substrate (54) and the abradable layer (58) are in the first cavity. (66) and the flow path (14). , this cooling hole (76) has an outlet in the abradable layer (58), and the cooling hole (76) has an outlet in the abradable layer (58). (112) to reduce its internal stress as well as to said widened end (108) An outer air seal device (characterized in that it provides a passageway for conveying cooling air) 44). The cooling fluid exiting the 8 cooling holes (76) leaves a film of cooling fluid on the flow surface (52). The cooling holes (76) extend to the radius of the turbomachine (12) so as to promote the formation of a 8. The outer air seal device of claim 7, wherein the outer air seal device is angled about a directional axis. 9 The turbomachine (12) includes a flow passage (14) oriented around a longitudinal axis and has a segment The component (46) has a segment (46) therein extending radially outwardly of the channel (14). a turbomachine (12) with an installation situation within the turbomachine (12) forming a flow surface; The segment (46) for the outer air seal device (44) of the segment (4 a substrate (54) containing means for holding the substrate (6); a plurality of disposed externally of the impingement cover (54) and extending through the impingement cover (56); an impingement cover (56) containing an opening (72); defined by the separation between the belt cover (56) and the substrate straight (54). a first cavity (66) and a substrate ( 54) an inner abradable material layer (58) and an aperture (72); so that the cooling fluid passes through the aperture (72) and impinges on the substrate (54). Provides communication between the cavity (66) and the source of cooling fluid, and 4) and the abradable layer (58) has a plurality of cooling holes (7) extending therethrough. 6), the cooling hole (76) has an outlet in the abradable layer (58), and the cooling hole (76) has an outlet in the abradable layer (58). The installation state of the cooling hole (76) is such that the cooling fluid exiting the cooling hole (76) is placed on the flow surface (52). ) to force the formation of a film of cooling fluid over the turbomachinery (12 segment (46) characterized in that it is angled with respect to the radial axis of ) . 10 The turbomachine (12) includes a flow passage (14) oriented about a longitudinal axis and has a segment The member (46) has a segment (46) therein facing radially outwardly of the channel (14). The turbomachine (1) has an installation situation in the turbomachine (12) that forms a flow surface of The segment (46) for the outer air seal device (44) of 2) is at least means having a flared end (108) and retaining the segment (46); a substrate (54) containing the substrate (54); includes a plurality of apertures (72) extending through the impingement cover (56). Impingement cover (56), impingement cover (56) and subsub a tray (54) and located at said flared end (108); a first cavity (66) having a longitudinally extending chamber (112); Abradable material inside the substrate (54) forming a flow surface (52) a layer (58) and an aperture (72) for allowing cooling fluid to pass through the aperture (72). cavity (66) and the cooling fluid source to impinge on the substrate (54). The substrate (54) and the abradable layer (58 ) includes a plurality of cooling holes (76) extending therethrough; has an outlet in the abradable layer (58), and the chamber (112) is located inside the abradable layer (58). for conveying cooling air to said flared end (108) as well as reducing stress. A segment (46) characterized in that it provides a passageway.