# US 11,527,228 B2 · Fairings for power generation machines > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,527,228 B2 - Document ID: US11527228B2 - Status: Granted - Kind: B2 - Application number: 16/266,411 - Filed: 2019-02-04 - Published: 2019-08-22 - Granted: 2022-12-13 - Earliest claimed: 2018-02-21 - Assignees: ROLLS-ROYCE plc - Applicants: ROLLS-ROYCE plc - Inventors: Richard Peace; Oliver C. Taylor-Tibbott; John G. Marshall - Web page: https://patentgrep.com/patent/US11527228B2 ## CPC - G10K 11/168: Plural layers of different materials, e.g. sandwiches - F01D 25/24: Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) - F02C 7/045: having provisions for noise suppression - F02C 7/24: Heat or noise insulation (air intakes having provisions for noise suppression F02C7/045; turbine exhaust heads, chambers, or the like F01D25/30; silencing nozzles of jet-propulsion plants F02K1/00) - F02K 1/827: {Sound absorbing structures or liners} - G10K 11/172: using resonance effects - H02K 5/24: specially adapted for suppression or reduction of noise or vibrations - H02K 7/1823: {structurally associated with turbines or similar engines} - F05D 2260/963: by Helmholtz resonators - F05D 2300/603: Composites; e.g. fibre-reinforced - F05D 2300/613: Felt - G10K 2210/32272: Helmholtz resonators - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR - 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) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material; a second layer comprising a composite; and a third layer positioned between the first layer and the second layer, the third layer being configured to attenuate acoustic waves over a predetermined frequency range. ## Claims ### Claim 1 A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material and defining a first surface and an opposite second surface, the first layer being configured for coupling the fairing to the power generation machine via one or more fasteners, wherein the first surface of the first layer has a concave shape, and wherein the first layer defines one or more receptacles open to the power generation machine; a second layer comprising a composite material, wherein the second layer defines a first surface and a second opposite surface, the second surface of the second layer defining an external surface of the fairing, the second surface of the second layer having a convex shape; and a third layer positioned within the one or more receptacles, the third layer being configured to attenuate acoustic waves over a predetermined frequency range. ### Claim 2 (depends on 1) A fairing as claimed in claim 1, wherein the second layer defines a plurality of apertures and the third layer defines a plurality of cavities, the plurality of apertures and cavities are aligned and define a plurality of Helmholtz resonators. ### Claim 3 (depends on 2) A fairing as claimed in claim 2, wherein the third layer comprises a honeycomb structure. ### Claim 4 (depends on 1) A fairing as claimed in claim 1, wherein the third layer comprises a wire mesh arranged to form a plurality of loops, wherein the wire is selected to attenuate the acoustic waves over the predetermined frequency range by converting acoustic energy to thermal energy. ### Claim 5 (depends on 1) A fairing as claimed in claim 1, wherein the third layer is bonded to the first layer. ### Claim 6 (depends on 1) A fairing as claimed in claim 1, wherein the first surface of the first layer comprises a portion that is shaped to match a surface of the power generation machine, the portion for being adhered to the power generation machine. ### Claim 7 (depends on 1) A fairing as claimed in claim 1, wherein the second layer defines a first surface and a second opposite surface, the second surface of the second layer defining an external surface of the fairing. ### Claim 8 (depends on 1) A fairing as claimed in claim 1, wherein the first layer is configured to enable the fairing to comply with ISO2685:1998. ### Claim 9 (depends on 1) A fairing as claimed in claim 1, wherein the second layer comprises no protrusions extending from the second surface of the second layer to minimize excrescence drag. ### Claim 10 (depends on 1) A fairing as claimed in claim 1, wherein the metallic material of the first layer comprises aluminium or titanium. ### Claim 11 (depends on 1) A fairing as claimed in claim 1, wherein the composite material of the second layer comprises a carbon composite or an oxide ceramic matrix composite. ### Claim 12 (depends on 1) Apparatus comprising: a power generation machine; and a fairing as claimed in claim 1, the first layer of the fairing being coupled to the power generation machine. ### Claim 13 (depends on 12) Apparatus as claimed in claim 12, wherein the power generation machine is a gas turbine engine. ### Claim 14 (depends on 12) Apparatus as claimed in claim 12, wherein the power generation machine is an electrical machine.