SANDWICH ARRANGEMENT WITH CERAMIC PANELS AND CERAMIC FELTS

Abstract

The disclosure relates to a sandwich arrangement having at least two peripheral disposed ceramic panels and a ceramic felt which is inserted between a first and second ceramic panel, The material of the first ceramic panel is equal or different to the material of the second panel, wherein the ceramic felt is formed by a textile structure with a regularly or quasi-regularly structured woven fibres. The fibres are made of at least one material and/or composition, wherein at least one adhesive is provided between an underside of the panels and adjacent fibres.

Claims

1. A sandwich arrangement comprising at least one of, in a partial or integral combination, the following structures: a) at least one ceramic matrix composite (CMC) skin surrounding a felt or composite woven textile structure; b) outer and inner layers, where one CMC skin is attached to a felt which forms the inner or the outer layer, or a composite woven textile structure0 which forms the inner layer; c) a reversed sandwich structure where the CMC has a different structured skin, which forms a core of the structure surrounded by two skins made of ceramic felt; and d) an additional structure where a ceramic felt is an outer layer, a CMC is a middle layer, and a composite woven textile structure is a inner layer.

2. A sandwich arrangement comprising: at least one peripheral disposed ceramic panel; and a ceramic felt actively connected to the ceramic panel; wherein the ceramic felt is formed by a textile structure with regularly or quasi-regularly structured woven fibres; wherein the fibres are made of at least one material and/or composition; and wherein at least one adhesive is provided between an underside of the ceramic panel and adjacent fibres of the felt or composite woven textile.

3. A sandwich arrangement comprising: at least two peripheral disposed ceramic panels; and a ceramic felt which is inserted between a first and second of the ceramic panels; wherein a material of the first ceramic panel is equal or different to a material of the second panel; wherein the ceramic felt is formed by textile structure with a regularly or quasi-regularly structured woven fibres, wherein the fibres are made of at least one material and/or composition; and wherein at least one adhesive is provided between an underside of at least one of the panels and adjacent fibres, or a compound between the ceramic panels and the adjacent ceramic felt is a cold-pressed or hot pressed moulding of various components of the sandwich arrangement.

4. (canceled)

5. (canceled)

6. The sandwich arrangement according to claim 1, wherein the ceramic felt is formed of irregular fibres intermixed with each other.

7. The sandwich arrangement according to claim 1, wherein the ceramic panel and/or ceramic felt are built upon a multiwall structure; wherein individual walls are spaced from each other; wherein the walls are mutually supported by a supporting structure; and wherein resulting spaces between supporting structures possess a light, medium or strong permeability.

8. The sandwich arrangement according to claim 1, wherein the sandwich arrangement contains as an internal structure a woven fabric or felt, fully or partly infiltrated in order to provide an internal cooling channel structure and/or insulation as well as reinforcement within at least one CMC skin shell.

9. The sandwich arrangement according to claim 1, characterised in that wherein the ceramic panel consists of one or more plies, wherein the plies are made of a same material and composition or differentiated among themselves.

10. The sandwich arrangement according to claim 1, wherein at least one surface of the ceramic panel comprises: one or more coatings.

11. The sandwich arrangement according to claim 1, wherein the sandwich structure comprises: impregnated ceramic tissue in-between CMC skins.

12. The sandwich arrangement according to claim 1, wherein the sandwich material consists of a wrapped CMC material, which is partly or fully infiltrated by a slurry technique, or impregnated by CVD or other method.

13. The sandwich arrangement according to claim 1, wherein the sandwich arrangement comprises: at least one intermediate ceramic panel.

14. The sandwich arrangement according to claim 1, wherein an interspace between the first or second ceramic panel and an intermediate ceramic panel is filled with a same or differentiated ceramic felt.

15. The sandwich arrangement according to claim 1, wherein at least one ceramic panel or at least one intermediate ceramic panel and/or ceramic felt are provided with cooling holes and/or cooling channels.

16. The sandwich arrangement according to claim 15, wherein the cooling holes or cooling channels are arranged in-between of ceramic panels and/or ceramic felt.

17. The sandwich arrangement according to claim 1, comprising: a cooling structure using as a composite woven textile, which is made of a mixing carbon and/or ceramic fibres.

18. The sandwich arrangement according to claim 15, comprising: a seal arranged for sealing off a flow of the a cooling medium through a ceramic panel, an intermediate ceramic panel, a ceramic felt, and a composite woven textile from the outside.

19. The sandwich arrangement according to claim 15, configured to allow a cooling medium to flow partially or integrally through a ceramic panel and/or intermediate ceramic panel and/or ceramic felt.

20. The sandwich arrangement according to claim 1, configured for a partial or integral use in hot gas path components of a turbomachinery or gas turbine engine.

21. The sandwich arrangement according to claim 20, in combination with the hot gas path component, which hot gas path component is an airfoil of a rotor blade or stator vane, wherein the airfoil comprises: at least one flow-applied outer shell; and at least one under-structure element, wherein the flow-applied outer shell is formed as an uniform or segmented structure, complying with aerodynamic final aims of the airfoil in a flow direction of working medium referring to the gas turbine engine or turbomachinery.

22. The sandwich arrangement according to claim 21, wherein the airfoil under-structure element is at least one intermediate shell and/or at least one spar.

23. The sandwich arrangement according to claim 22, wherein the flow-applied outer shell is equipped in a region of a leading edge and/or trailing edge with an insert, wherein the insert is made of monolithic ceramic material or a combination of monolithic ceramic material with CMC skins.

24. The sandwich structure according to claim 23, wherein the insert is provided with a structured internal cooling structure.

25. The sandwich arrangement according to claim 24, wherein the insert is provided with continuous and/or quasi-continuous cooling holes serving as emergency cooling system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The present invention is now be explained more closely by means of different embodiments and with reference to the attached drawings.

[0076] FIG. 1 shows a sandwich arrangement;

[0077] FIG. 2 shows an enlarged view of a region of FIG. 1 reflecting most simple type of CMC fabric texture;

[0078] FIG. 3 shows a cross sectional view of the region according to FIG. 2, as seen along line FIG. 3-FIG. 3;

[0079] FIGS. 4a-e show various textile architectures reflecting mixed CMC textures, carbon fibres woven together with ceramic fibres, oxide or non-oxide;

[0080] FIGS. 5a-b show further textile architectures including an integration of cooling holes in textiles;

[0081] FIGS. 6a-c show an intermediate layer which is designated as flexible layer that will i) compensate the CTE (Coefficient of Thermal Expansion) mismatch between the metallic core of hot gas path components and the ceramic shell; ii) support the CMC structure in case of FOD (Foreign Object Damage) (flexible backup structure); iii) act as substructure for cooling air distribution;

[0082] FIG. 7 shows a cross-section through a rotor blade or stator vane airfoil, in the case an additional use of an intermediate layer, which is composed of a honeycomb-like structure;

[0083] FIG. 7a shows a summarised flexible concept of a CMC airfoil with reinforcement feature;

[0084] FIG. 8 shows a cross-section through a rotor blade or stator vane airfoil, in the case an additional use of at least one intermediate layer, which is composed of a honeycomb-like structure, wherein at least one intermediate layer is integrally or quasi-integrally embedded in a ceramic felt, which fills the spaces between the spar and the outer shell;

[0085] FIG. 9 shows a further airfoil embodiment, which largely corresponds to the preceding FIGS. 7 and 8, wherein the space between the flow-applied outer shell and relatives spars is bridged by regularly or irregularly distributed elevations or contact points;

[0086] FIG. 9a-b show various configured ropes;

[0087] FIG. 10 shows a further airfoil embodiment, which largely corresponds to the preceding FIGS. 7 and 8, wherein the space between the flow-applied outer shell and relatives spars is bridged by regularly or irregularly distributed elevations, wherein at least one intermediate layer is integrally or quasi-integrally embedded in a ceramic, which fills the spaces between the spar(s) and outer shell;

[0088] FIG. 10a-b show various configured ropes or spacing modules;

[0089] FIG. 11 shows a further embodiment which is provided with two reinforcement inserts at the LE and TE, respectively;

[0090] FIG. 12 shows the positioned insert in connection with an airfoil;

[0091] FIG. 13 shows the internal structure of a LE insert comprising structured/controlled porous architecture enabling a strong and very efficient cooling of the insert.

[0092] FIG. 14 shows the internal structure of a LE insert comprising a special structured/controlled porous architecture enabling a strong and very efficient cooling of the insert.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

[0093] FIG. 1 shows a partial longitudinal section through an embodiment of multi-plies CMC provided as a sandwich system. Fundamentally, the embodiment CMC material can be designed with individualized fibre structure in accordance with the operational requirements. A certain percentage of the fibres exhibits differentiated diameters, which are intended to mainly carry the mechanical load (in the case of the larger diameters) within the CMC section of the hot gas path parts during operation. The outermost panels 101a, 101b of the sandwich system (100, 101a, b, 110, . . . ) consist of one or more plies, wherein at least one of the panel 101 possesses an integral or quasi-integral smooth protective coating 100 having a strong contact with the adjacent ceramic structure of the panel. In many applications, but not exclusively, it is preferably that the fibres of the first panel 101a have the same composition and/or material as the fibres of the second panel 101b, which is disposed on the opposite side. The fibres of the first and second panels may be impregnated with the same or different material and it may be provided that only part of the circumference of the fibres are impregnated, wherein the impregnated side is designed as a function of the installation, for example, that the impregnated side of the fibres is the side which is bonded to the first or second layer 101a, 101b.

[0094] The mentioned layers can consist of a laminate structure, such that an appropriate bond between the single intermediate layers (different textile plies) is achieved. Furthermore, the layers can be formed by a multiple sandwich structure.

[0095] The intermediated ceramic felt 110 between the panels, likewise build-up of 2D/3D textile structure with thinner fibres, serves to fix the ceramic matrix to the overall fibre substructure and to deflect the local forces of mechanical loading into the ceramic matrix. As shown in FIG. 1, items 111, 112, 113, the fibres of the intermediate ceramic felt 110 can be differently woven using the same or different materials, such that the contact surface within the ceramic felt and on each side of the panels comprises both first and second fibre materials. The architecture according to item 111 represents a rectangular or quasi-rectangular weaving, the architecture according to item 113 represents an oblique or quasi-oblique or non-rectangular angulation weaving; the architecture according to item 112 represents sinusoidal or quasi-sinusoidal interdigitated weaving. Any stacking-sequence of different woven fibres (111, 112, 113, etc.) within the thickness of the sandwich arrangement is also possible.

[0096] FIG. 2 shows the external surface of the fibres 111a and 111b within the ceramic felt 110 based on the woven sector 111. The external surface of the fibres 111a, 111b is exposed equally on both sides of the structured three-dimensional, such that the contact surface on each comprises both first and second materials of the fibres. FIG. 3 shows a sectional view of the weave along line FIG. 3-FIG. 3 as shown in FIG. 2. In this field, single fibre or several fibres 111a, 111b comprise in the circumferential direction regularly or irregularly arranged ropes or punctual particles attached to the fibres 120 for a maximized friction with each other (111a, 111b) and within the whole structure of the ceramic felt 110.

[0097] FIG. 4 shows various textile architectures (a-e) of sandwich structures, wherein FIG. 5 (a, b) shows an exemplary integration of cooling holes (effusion and/or convective and/or impingement cooling) in textiles: Textiles woven with integrated hole-structure 150 used in hot areas where film cooling must be implemented. It can be under the form of a single cooling holes row or of cooling holes that are extending also over a wider area.

[0098] FIG. 6 shows an intermediate layer which is designated as flexible layer that will compensate the CTE (Coefficient of Thermal Expansion) mismatch between the metallic core of hot gas path components and the ceramic shell. The intermediate layer can be made of a 3D-structured metallic grid (not depicted in the FIG. 6) or as an undulated metallic or ceramic structure, e.g. honeycomb-like, (see FIGS. a-c).

[0099] FIGS. 7 to 10 show a cross-section through a rotor blade or stator vane airfoil. The interior of the airfoil is provided with a perpendicular oriented and modular spar (made of one or several modules), which divides the interior into two individualized parts, namely spar 1 (item 200) and spar 2 (item 300). It could also be made of more than 2 spar modules.

[0100] FIG. 7 shows an additional use of an intermediate layer 400, which, for example, is composed of a honeycomb-like structure. A flexible intermediate layer 400 consists of a heat and oxidation resistant material and can be compensated the CTE (Coefficient of Thermal Expansion) mismatch between the ceramic/CMC composed surrounding and flow-applied outer shell 500 and metallic spars 200, 300. The intermediate layers 400a (associated with spar 1) and 400b (associated with spar 2) can comprise the faculty to absorb any shock in case of foreign object impact and avoid a complete disintegration of damaged CMC outer shell 500 or other liner systems. Such an intermediate layer can also function as a spacer. Such 3D intermediate layer structure can be made of a 3D-structured metallic grid or in form of a corrugated metallic structure, exhibiting a honeycomb-like or any similar texture.

[0101] FIG. 7a shows a CMC sections. Reinforced 2D woven inorganic textile sheet material (one or multiple layers) can be wrapped around a central metallic, polymer or ceramic 3D body that is used as mould. Such a mould might represent a turbine airfoil or inner/outer platform contour or other hot gas path components and can additionally also include local cooling air hole patterns (external film cooling). The final CMC body can be then positioned around a central metallic spar (see FIG. 7, items 200, 300) allowing a correct, precise positioning, mechanical support and, if necessary, enabling to cool the CMC airfoil shell.

[0102] FIG. 8 shows an additional use of an intermediate layer 400, which, for example, is composed of a honeycomb-like structure. A flexible intermediate layer 400 consists of a heat and oxidation resistant material and can be compensated the CTE (Coefficient of Thermal Expansion) mismatch between the ceramic/CMC composed surrounding and flow-applied outer shell 500 and metallic spars 200, 300. The intermediate layers 400a (associated with spar 1), 400b (associated with spar 2) can comprise the faculty to absorb any shock in case of foreign object impact and avoid a complete disintegration of damaged CMC outer shell 500 or other liner systems. Such 3D intermediate layer structure can be made of a 3D-structured metallic grid or in form of a corrugated metallic structure, exhibiting a honeycomb-like or any similar texture. Additionally, the intermediate layers 400a, 400b are integrally or quasi-integrally embedded in a ceramic felt 600, which fills the spaces between the spar(s) and outer shell. The core of at least one intermediate space (not shown) may be filled with ceramic felt, with different/varying composite and consistency, as required.

[0103] FIG. 9 shows a further airfoil embodiment, which largely corresponds to the preceding FIGS. 7 and 8. The space between the flow-applied outer shell 500 and spars 200, 300 is bridged by regularly or irregularly distributed elevations 210, 310, which are equipped with differently configured ropes/spacing points, namely round 220 and/or T-shape 230 ropes, whereby such an arrangement comprises the faculty to absorb any shock of foreign object impact and can be compensated the CTE (Coefficient of Thermal Expansion) mismatch between the surrounding and flow-applied outer shell 500 and metallic spars 200, 300.

[0104] FIG. 10 shows a further airfoil embodiment, which largely corresponds to the preceding FIGS. 7 and 8. The space between the outer shell 500 and spars 200, 300 is bridged by regularly or irregularly distributed elevations 210, 310, which are equipped with differently configured ropes, namely round 220 and/or T-shape 230 ropes, whereby such an arrangement comprises the faculty to absorb any shock of foreign object impact and can be compensated the CTE (Coefficient of Thermal Expansion) mismatch between the surrounding and flow-applied outer shell 500 and metallic spars 200, 300. Additionally, the intermediate layers 400a, 400b are integrally or quasi-integrally embedded in a ceramic felt 610, which fills the spaces between the spar(s) and outer shell.

[0105] In another embodiment of this invention according to FIG. 11, the CMC shell 550 is manufactured as one singular part, including Suction Side (SS) and Pressure Side (PS) sections, whereas only the airfoil areas are infiltrated in a first step with the matrix material, dried and cured (including the concrete cooling hole-pattern). After accomplishment of this partial manufacturing, the CMC shell system is positioned around the central metallic core (spar) 250 with a pre-positioned metallic interlayer structure. This intermediate layer 450 is joined by active brazing, gluing with high temperature resistant cements, mechanical fixation or a combination of the mentioned methods around the spar 250 (metallic central core). SS and PS CMC sections are then wrapped around the fully pre-manufactured and prepositioned inner Leading Edge (LE) and Trailing Edge (TE) section or other thermally and thermos-mechanically loaded areas, which are made of monolithic ceramic material or a combination of monolithic with CMC skins. Such reinforcement inserts 620 can also include an inner as well as interconnected outer cooling system 630. This system can be either emergency cooling holes as designed or directly through-going CAHs. Emergency cooling holes that get open to the outer shell surface in case of shell gets damages.

[0106] These holes could also be designed from the beginning as through-going CAHs depending on the outer surface cooling requirements of the part.

[0107] Each of FIGS. 12, 13, and 14 show an additional porous body 640 as a natural continuation of the insert 620, strictly positioned in the area of the leading edge LE. The interior of the insert 620 may have a structured porous structure creating interconnected cooling cavities (see FIGS. 13 and 14) or an unsorted filling with a ceramic material such as a felt, wherein the density and/or permeability can be varied as required.

LIST OF REFERENCE NUMEROUS

[0108] Sandwich Arrangement 100, 101a, 101b, 110, . . .

[0109] 100 Coating

[0110] 101a Ceramic first panel

[0111] 101b Ceramic second panel

[0112] 110 Ceramic felt

[0113] 111 Woven structure

[0114] 111a External structure of the fibres

[0115] 111b External structure of the fibres

[0116] 112 Woven structure

[0117] 113 Woven structure

[0118] 120 Fibre ropes

[0119] 150 Textiles woven with integrated hole-structure

[0120] 200 Spar

[0121] 210 Elevations

[0122] 220 Round ropes

[0123] 230 T-shape ropes

[0124] 250 Spar

[0125] 300 Spar

[0126] 310 Elevations

[0127] 400 Intermediate layer

[0128] 400a Intermediate layer associated with spar 200

[0129] 400b Intermediate layer associated with spar 300

[0130] 450 Intermediate layer

[0131] 500 Flow-applied outer shell

[0132] 550 CMC shell

[0133] 600 Ceramic felt

[0134] 610 Ceramic felt

[0135] 620 Reinforcement insert with controlled/engineered porous structure

[0136] 630 Cooling system

[0137] 640 Porous body

[0138] SS Suction side

[0139] PS Pressure side

[0140] LE Leading edge

[0141] TE Trailing edge