# US 2023/0053784 A1 · Nacelle cowling structure for a turbomachine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0053784 A1 - Document ID: US20230053784A1 - Status: Published application - Kind: A1 - Application number: 17/408,723 - Filed: 2021-08-23 - Published: 2023-02-23 - Earliest claimed: 2021-08-23 - Assignees: Rolls-Royce Deutschland Ltd & Co KG - Applicants: Rolls-Royce Deutschland Ltd & Co KG - Inventors: Roland NIKOLAUS; Michael SCHACHT - Web page: https://patentgrep.com/patent/US20230053784A1 ## CPC - F01D 25/26: Double casings; Measures against temperature strain in casings - B64D 29/08: Inspection panels for power plants - 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} - F02K 3/06: with front fan - 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 - F05D 2250/283: honeycomb - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Embodiments of the invention are shown in the figures, where a nacelle cowling structure for a turbomachine having a bypass duct defining a path for an airflow is provided, the nacelle cowling structure including: an outer layer defining an external surface of the nacelle cowling structure, an inner layer defining a surface of the bypass duct, a front mounting area for fixation to the turbomachine and a rear mounting area for fixation to the turbomachine downstream the front mounting area with respect to the bypass duct flow path, wherein a space between the outer and inner layers and between the front and rear mounting areas is filled with acoustic material. ## Claims ### Claim 1 A nacelle cowling structure for a turbomachine having a bypass duct defining a path for an airflow, the nacelle cowling structure comprising: an outer layer defining an external surface of the nacelle cowling structure, an inner layer defining a surface of the bypass duct, a front mounting area for fixation to the turbomachine and a rear mounting area for fixation to the turbomachine downstream the front mounting area with respect to the bypass duct flow path, wherein a space between the outer and inner layers and between the front and rear mounting areas is filled with acoustic material. ### Claim 2 (depends on 1) The nacelle cowling structure according to claim 1, further having an access opening extending through the outer layer, acoustic material, and inner layer. ### Claim 3 (depends on 2) The nacelle cowling structure according to claim 2, further comprising a door closing the access opening in a closed state and providing access to the bypass duct in an opened state. ### Claim 4 (depends on 3) The nacelle cowling structure according to claim 3, the door having an outer layer defining a part of the external surface of the nacelle cowling structure and an inner layer defining a part of the surface of the bypass duct, and acoustic material in between. ### Claim 5 (depends on 3) The nacelle cowling structure according to claim 3, the door being connected to the nacelle cowling structure inner layer by means of at least one of a hinge and a latch. ### Claim 6 (depends on 1) The nacelle cowling structure according to claim 1, wherein the inner layer comprises the front and rear mounting areas. ### Claim 7 (depends on 1) The nacelle cowling structure according to claim 1, wherein the outer layer comprises a carbon composite material, the inner layer comprises at least one of a composite material and a metal, and the acoustic material comprises a honeycomb structure. ### Claim 8 (depends on 1) The nacelle cowling structure according to claim 1, wherein the outer layer is mounted on the inner layer, and the inner layer carries the outer layer. ### Claim 9 (depends on 1) The nacelle cowling structure according to claim 1, wherein each of the front and rear mounting areas comprises a flange. ### Claim 10 (depends on 1) The nacelle cowling structure according to claim 1, wherein the acoustic material is a sound absorber. ### Claim 11 (depends on 1) The nacelle cowling structure according to claim 1, having a cylindrical or curved shape. ### Claim 12 (depends on 1) The nacelle cowling structure according to claim 1, surrounding an area for housing a core of the turbomachine, the core comprising combustion equipment. ### Claim 13 A nacelle cowling structure for a turbomachine having a bypass duct defining a path for an airflow, the nacelle cowling structure comprising: an outer layer defining an external surface of the nacelle cowling structure, an inner layer defining a surface of the bypass duct, wherein an acoustic material is arranged in a space between the outer and inner layers, the nacelle cowling structure further having an access opening extending through the outer layer, acoustic material, and inner layer. ### Claim 14 (depends on 1) The nacelle cowling structure of claim 1, wherein the front mounting area is fixed to a case of the turbomachine and the rear mounting area is fixed to a turbomachine core of the turbomachine. ### Claim 15 (depends on 14) The nacelle cowling structure according to claim 14, wherein a fan directs an airflow through the bypass duct and the turbomachine core, wherein the bypass duct surrounds the turbomachine core. ### Claim 16 (depends on 14) The nacelle cowling structure according to claim 14, wherein the turbomachine is an aircraft engine and the turbomachine core comprises a gas turbine engine. ### Claim 17 (depends on 14) The nacelle cowling structure according to claim 14, wherein the front mounting area is fixed to the case by means of a bolted connection and the rear mounting area is fixed to the turbomachine core by means of a bolted connection. ### Claim 18 (depends on 14) The nacelle cowling structure according to claim 14, providing a mechanical connection to an exhaust system. ### Claim 19 (depends on 18) The nacelle cowling structure according to claim 18, wherein the exhaust system comprises a fixed nozzle, a thrust reverser, a variable exhaust nozzle or an afterburner, or a combination thereof. ### Claim 20 A nacelle cowling structure for a turbomachine having a bypass duct defining a path for an airflow, the nacelle cowling structure comprising: an outer part comprising or being formed by an outer layer defining an external surface of the nacelle cowling structure, an inner part comprising an inner layer defining a surface of the bypass duct, an acoustic material and a load-carrying backskin, a front mounting area for fixation to the turbomachine and a rear mounting area for fixation to the turbomachine downstream the front mounting area with respect to the bypass duct flow path, wherein a space is formed between the outer and inner layers, and wherein the outer and inner parts are connected with one another between the front and rear mounting areas by means of bulkheads and ribs.