# US 11,905,892 B2 · Flow machine performance modelling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,905,892 B2 - Document ID: US11905892B2 - Status: Granted - Kind: B2 - Application number: 17/101,932 - Filed: 2020-11-23 - Published: 2021-06-03 - Granted: 2024-02-20 - Earliest claimed: 2019-11-29 - Assignees: ROLLS-ROYCE plc - Applicants: ROLLS-ROYCE plc - Inventors: Vasileios Pachidis; Luis E Ferrer-Vidal Espana-Heredia - Web page: https://patentgrep.com/patent/US11905892B2 ## CPC - F02C 9/16: Control of working fluid flow (F02C9/48 takes precedence; control of air-intake flow F02C7/057) - F01D 21/003: {Arrangements for testing or measuring (for measuring vibrations G01H)} - F04D 27/001: {Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring} - G06F 30/20: Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) - F05D 2220/3216: for a special compressor stage - F05D 2260/81: Modelling or simulation - F05D 2270/3015: differential pressure - F05D 2270/304: Spool rotational speed - F05D 2270/3061: of the working fluid - F05D 2270/44: active, predictive, or anticipative - 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) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A method of determining performance characteristics of a flow machine having a rotor interacting with a flow field. The method comprises: receiving performance data for the flow machine comprising data values of a performance parameter of the rotor and mass flow for the flow machine at one or more defined rotor condition, the performance data defining a two-dimensional array of data in which points for a common rotor condition are identifiable; determining or receiving exit mass flow values for the flow downstream of the rotor; and identifying one or more point in the received performance data and interpolating from said one or more point to a corresponding one or more point at a different rotor condition based on a correlation of the exit mass flow values for said points. ## Claims ### Claim 1 A method of determining performance characteristics of a flow machine having a rotor interacting with a flow field, the method comprising: receiving performance data for the flow machine comprising data values of a performance parameter of the rotor and mass flow for the flow machine at one or more defined rotor condition, the performance data defining a two-dimensional array of data in which points for a common rotor condition are identifiable; determining or receiving exit mass flow values for the flow downstream of the rotor; and identifying one or more point in the received performance data and interpolating from the one or more point to a corresponding one or more point at a sub-idle rotor condition based on a correlation of the exit mass flow values for the points. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more corresponding point represents a predicted performance parameter value for the sub-idle rotor condition. ### Claim 3 (depends on 1) The method of claim 1, wherein the defined rotor condition comprises a fixed rotor speed. ### Claim 4 (depends on 1) The method of claim 1, wherein the received performance data comprises one or more rotor speed. ### Claim 5 (depends on 1) The method of claim 1, wherein the performance parameter of the rotor comprises a pressure change across the rotor. ### Claim 6 (depends on 1) The method of claim 1, wherein the points in the performance data corresponding to the common rotor condition define a line in the two-dimensional data array. ### Claim 7 (depends on 1) The method of claim 1, wherein the two-dimensional array of data defines a performance map for the rotor. ### Claim 8 (depends on 1) The method of claim 1, wherein the received performance data comprises inlet mass flow values for the rotor and the exit mass flow values are calculated from the inlet mass flow values. ### Claim 9 (depends on 1) The method of claim 1, wherein the exit mass flow values define a line in the two-dimensional data array along which interpolation is performed. ### Claim 10 (depends on 1) The method of claim 1, wherein the interpolation comprises interpolating from the identified point in the received performance data to a corresponding point at the sub-idle rotor condition based on following a line of constant exit mass flow in the two-dimensional array. ### Claim 11 (depends on 1) The method of claim 1, wherein the interpolation comprises moving from the identified point in a direction of constant exit mass flow by a determined distance to identify the location of the corresponding point. ### Claim 12 (depends on 1) The method of claim 1, wherein a plurality of corresponding points for the sub-idle rotor condition are identified by interpolation and a line comprising the plurality of corresponding points in the two-dimensional array is determined in order to define a performance characteristic for the rotor at the the sub-idle rotor condition. ### Claim 13 (depends on 1) The method of claim 1, wherein the flow machine comprises a compressor or turbine of a gas turbine engine. ### Claim 14 A non-transitory computer readable storage medium comprising machine readable instructions for a data processor to determine performance characteristics of a flow machine having a rotor interacting with a flow field, by: receiving performance data for the flow machine comprising data values of a performance parameter of the rotor and mass flow for the flow machine at one or more defined rotor condition, the performance data defining a two-dimensional array of data in which points for a common rotor condition are identifiable; determining or receiving exit mass flow values for the flow downstream of the rotor; identifying one or more point in the received performance data; and, interpolating from the one or more point to a corresponding one or more point at a sub-idle rotor condition based on a correlation of the exit mass flow values for the points. ### Claim 15 A system for analysing flow machine behaviour, comprising: a flow machine having a rotor configured to interact with a flow field and a plurality of sensors for sensing performance parameter values for the rotor and an operational rotor condition; and, a data processor configured to receive the performance parameter values data values and mass flow values for the flow machine at one or more defined rotor condition value, the performance parameter and mass flow values defining a two-dimensional array of data in which points for a common rotor condition are identifiable, determine or receive exit mass flow values for the flow downstream of the rotor, identify one or more point in the received performance data, interpolate from the one or more point to a corresponding one or more point at a sub-idle rotor condition based on a correlation of the exit mass flow values for the points, and output the corresponding one or more points for the sub-idle rotor condition. ### Claim 16 (depends on 15) The system of claim 15, wherein the one or more corresponding point represents a predicted performance parameter value for the sub-idle rotor condition. ### Claim 17 (depends on 15) The system of claim 15, wherein the defined rotor condition comprises a fixed rotor speed. ### Claim 18 (depends on 15) The system of claim 15, wherein the received performance data comprises one or more rotor speed. ### Claim 19 (depends on 15) The system of claim 15, wherein the performance parameter of the rotor comprises a pressure change across the rotor. ### Claim 20 (depends on 15) The system of claim 15, wherein the points in the performance data corresponding to a common rotor condition define a line in the two-dimensional data array.