# US 2017/0284415 A1 · Fan housing and engine assembly with fan housing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0284415 A1 - Document ID: US20170284415A1 - Status: Published application - Kind: A1 - Application number: 15/463,489 - Filed: 2017-03-20 - Published: 2017-10-05 - Earliest claimed: 2016-04-01 - Assignees: Rolls-Royce Deutschland Ltd & Co KG - Applicants: Rolls-Royce Deutschland Ltd & Co KG - Inventors: Moritz WIRTH - Web page: https://patentgrep.com/patent/US20170284415A1 ## CPC - F04D 29/541: {Specially adapted for elastic fluid pumps (F04D29/56 takes precedence)} - F01D 21/045: {special arrangements in stators or in rotors dealing with breaking-off of part of rotor} - F01D 25/243: {Flange connections; Bolting arrangements (F01D25/265 takes precedence)} - F02C 7/045: having provisions for noise suppression - F02K 3/06: with front fan - F04D 19/002: {Axial flow fans} - F04D 29/526: {Details of the casing section radially opposing blade tips (ducts F04D29/545)} - F04D 29/664: {by means of sound absorbing material} - F05D 2220/32: in gas turbines - F05D 2250/324: divergent - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A fan housing of a turbofan engine that forms an internal space surface at the inner side, delimiting a flow path through the fan of the turbofan engine radially outside, wherein the fan housing has a beginning of the housing that is arranged upstream. It is provided that a divergent cross-sectional surface extension of the flow path is realized by the internal space surface of the fan housing where it directly adjoins the beginning of the housing, and that the internal space surface of the fan housing is suited for continuously extending an inlet diffuser of an engine inlet, which is arranged upstream of the fan housing, into the area of the fan housing. The invention further relates to an engine assembly with a fan housing and an engine inlet. ## Claims ### Claim 1 A fan housing of a turbofan engine that forms an internal space surface at the inner side, delimiting the flow path through the fan of the turbofan engine radially outside, wherein the fan housing comprises a beginning of the housing that is arranged upstream, wherein a divergent cross-sectional surface extension of the flow path is realized by the internal space surface of the fan housing where it directly adjoins the beginning of the housing, and wherein the internal space surface of the fan housing is suited for continuously extending the inlet diffuser of an engine inlet, which is arranged upstream of the fan housing, into the area of the fan housing. ### Claim 2 (depends on 1) The fan housing according to claim 1, wherein the fan housing comprises a first area at the internal space surface, and a second area adjoining thereto in the axial direction, wherein the first area joins downstream to the beginning of the housing, and the second area is in the radial direction adjacent to the blade tips of the fan blades of the fan, and wherein the divergent cross-sectional surface extension is formed in the first area. ### Claim 3 (depends on 2) The fan housing according to claim 2, wherein the cross-sectional surface of the flow path at first increases in the flow direction in the first area of the internal space surface adjoining the beginning of the housing, and decreases again towards the second area of the internal space surface. ### Claim 4 (depends on 3) The fan housing according to claim 3, wherein the divergent cross-sectional surface extension is provided by a shape of the first area of the internal space surface that is concave towards the flow path. ### Claim 5 (depends on 2) The fan housing according to claim 2, wherein the internal space surface has a first radius at the beginning of the housing, has a first maximum radius in the first area, and in that the fan blades of the fan have a second maximum radius, wherein a) the first radius is larger than the second maximum radius, and b) the first maximum radius is larger than both the first radius and the second maximum radius. ### Claim 6 (depends on 2) The fan housing according to claim 2, wherein the housing components of the fan housing that belong to the first area are configured for receiving fan fragments in the event that a fan blade breaks, and for avoiding that they penetrate the engine nacelle surrounding the fan housing in an outward direction. ### Claim 7 (depends on 1) The fan housing according to claim 1, wherein the fan housing has a sound-absorbing panel adjoining the beginning of the housing that is connected only to one or multiple structural housing components of the fan housing, wherein the cross-sectional surface extension that is divergent where it adjoins the beginning of the housing is formed at least partially in the area of the panel. ### Claim 8 (depends on 1) The fan housing according to claim 1, wherein the fan housing has an attachment structure for connecting an engine inlets at the fan housing at the beginning of the housing that is arranged upstream. ### Claim 9 (depends on 8) The fan housing according to claim 8, wherein the attachment structure is formed as a flange. ### Claim 10 An engine assembly, comprising: a fan housing that forms an internal space surface at the inner side, delimiting a flow path through the fan of the turbofan engine radially outside, wherein the fan housing has a beginning of the housing that is arranged upstream, and an engine inlet that is connected upstream to the fan housing and that forms an inlet diffuser upstream of the connection between the fan housing and engine inlet over a defined length, wherein the inlet diffuser is continuously expanded in the axial direction into the area of the fan housing. ### Claim 11 (depends on 10) The engine assembly according to claim 10, wherein a divergent cross-sectional surface extension of the flow path is realized by the internal space surface of the fan housing where it directly adjoins the beginning of the housing, and the internal space surface thus extends the inlet diffuser, which is formed by the engine inlet, into the area of the fan housing. ### Claim 12 (depends on 11) The engine assembly according to claim 11, wherein the fan housing comprises a first area at the internal space surface, and a second area adjoining thereto in the axial direction, wherein the first area joins downstream to the beginning of the housing, and the second area is in the radial direction adjacent to the blade tips of the fan blades of the fan, and wherein the divergent cross-sectional surface extension is formed in the first area, wherein the cross-sectional surface at first increases in the flow direction in the first area of the internal space surface adjoining the beginning of the housing, and decreases again towards the second area of the internal space surface. ### Claim 13 (depends on 12) The engine assembly according to claim 12, wherein the internal space surface has a first radius at the beginning of the housing, has a first maximum radius in the first area, and in that the fan blades of the fan have a second maximum radius, wherein a) the first radius (R1) is larger than the second maximum radius, and b) the first maximum radius is larger than both the first radius and the second maximum radius. ### Claim 14 (depends on 11) The fan housing according to claim 11, wherein the fan housing has a sound-absorbing panel adjoining the beginning of the housing, which is connected only to one or multiple structural housing components of the fan housing, wherein the cross-sectional surface extension that is divergent where it adjoins the beginning of the housing is formed at least partially in the area of the panel. ### Claim 15 (depends on 10) The engine assembly according to claim 10, wherein the fan housing comprises a first attachment structure for connection to the engine inlet at the beginning of the housing, the engine inlet forms an inlet end that is arranged downstream, the engine inlet comprises at the inlet end a second attachment structure for connection to the fan housing, wherein the first and second attachment structures that are connected to each other form a connection structure at which the inlet end of the engine inlet and the beginning of the housing of the fan housing are connected to each other, the engine inlet forms an extension structure downstream of the inlet end, extending the inlet diffuser in the axial direction, and the extension structure extends downstream of the axial position of the connection structure in the mounted state, so that the inlet diffuser is extended in the axial direction into the area of the fan housing. ### Claim 16 (depends on 15) The engine assembly according to claim 15, wherein the extension structure is formed by a sound-absorbing panel. ### Claim 17 (depends on 15) The engine assembly according to claim 15, wherein the fan housing has a second area at the internal space surface, adjoining the fan blades of the fan in the radial direction, wherein the extension structure of the engine inlet extends in the axial direction maximally up to this second area. ### Claim 18 (depends on 15) The engine assembly according to claim 15, wherein the first attachment structure and the second attachment structure are respectively flanges and form a flange connection in the connected state. ### Claim 19 (depends on 10) The engine assembly according to claim 10, wherein the extension of the inlet diffuser in the axial direction into the area of the fan housing is formed in such a manner that the inlet diffuser has a continuously divergent cross-sectional surface extension in the transitional area between the engine inlet and the fan housing. ### Claim 20 (depends on 10) A turbofan engine comprising an engine assembly with the features of claim 10.