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US 12,709,991 B2Granted
Crosswind compensation for outdoor testing of turbofan aircraft engine
AssigneePratt & Whitney Canada Corp. (P&Wc)
InventorsFrancis Demers, Cristina Crainic
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Abstract
Systems and methods disclosed herein account for the crosswind effects when assessing the engine field margins based on a run in an outdoor facility where no thrust measurement is available. The impact of crosswinds on engine performance may be quantified by observing the differences in several engine performance parameters available in the field against a performance cycle model reference stored in data tables. The differences are compared to Average New Engine (ANE) margins to result in available margins.
Claims17
A method of crosswind compensation for an outdoor power assurance check test of a turbofan aircraft engine of an aircraft, comprising:
- preparing data for engine under test by:
- generating first tables representing average new engine (ANE) installed performance by running an estimated engine performance program (EEPP) to get expected values of a rotational speed of a high-speed spool (N2), an indicated turbine temperature (ITT), and combustor pressure (PB) with no deterioration and no crosswind effects;
- generating second tables of sensitivities of N2, ITT, and PB to high-pressure compressor (HPC) deterioration, high-pressure turbine (HPT) deterioration, and fan work scaling by running the EEPP;
- storing the first and second tables in a non-transitory storage accessible by an aircraft computer;
- receiving the turbofan aircraft engine observed parameters of N2, ITT, and PB at an N1R1A at the aircraft computer by operating the aircraft computer to perform the power assurance check test of the turbofan aircraft engine by:
- activating a brake of the aircraft;
- closing the turbofan aircraft engine bleed system, hydraulic, and electric loads;
- bringing the turbofan aircraft engine to Take-off power;
- recording ambient parameters and the engine observed parameters once the turbofan aircraft engine is stabilized;
- and
- bringing the turbofan aircraft engine back to idle;
- calculating a difference between the engine observed parameters of N2, ITT, and PB at the N1R1A and corresponding ANE values of from the first tables as first deltas ΔN2, ΔITT, and ΔPB;
- using the sensitivities from the second tables and the first deltas ΔN2, ΔITT, and ΔPB, solving a 3×3 system of equations to get a fan work scaling, an HPC efficiency debit, and an HPT efficiency debit;
- calculating second deltas ΔN2, ΔITT, and ΔPB to ΔNE performance without inlet bulk swirl effect using the sensitivities from the second tables and a calculated HPC deterioration and HPT deterioration, without fan work scaling;
- and
- calculating engine field margins for N2 and ITT by subtracting the second deltas ΔN2 and ΔITT from ΔNE field margins as an output for the outdoor power assurance check test.
13 more elements
A system for crosswind compensation of an outdoor power assurance check test of a turbofan aircraft engine of an aircraft, comprising:
- a first non-transitory storage medium having stored thereon first tables representing average new engine (ΔNE) installed performance determined by running an estimated engine performance program (EEPP) to get expected values of a rotational speed of a high-speed spool (N2), an indicated turbine temperature (ITT), and combustor pressure (PB) with no deterioration and no crosswind effects;
- a second non-transitory storage medium having stored thereon second tables of sensitivities of N2, ITT, and PB to high-pressure compressor (HPC) deterioration, high-pressure turbine (HPT) deterioration, and fan work scaler determined by running the EEPP;
- an aircraft computer;
- aircraft sensors configured to provide engine parameters of N2, ITT, and PB at an N1R1A to the aircraft computer;
- stored power assurance check test instructions configured to execute on the aircraft computer to:
- activate a brake of the aircraft;
- close the turbofan aircraft engine bleed system, hydraulic, and electric loads;
- bring the turbofan aircraft engine to Take-off power;
- record ambient and the engine parameters of N2, ITT, and PB at the N1R1A once the turbofan aircraft engine is stabilized;
- bring the turbofan aircraft engine back to idle;
- calculate a difference between the engine observed engine parameters of N2, ITT, and PB at the N1R1A and corresponding ΔNE values of from the first tables as first deltas ΔN2, ΔITT, and ΔPB;
- using the sensitivities from the second tables and the first deltas ΔN2, ΔITT, and ΔPB, solve a 3×3 system of equations to get fan work scaling, an HPC efficiency debit, and an HPT efficiency debit;
- calculate second deltas ΔN2, ΔITT, and ΔPB to ΔNE performance without inlet bulk swirl effect using the sensitivities from the second tables and a calculated engine HPC deterioration and HPT deterioration without fan work scaling;
- and
- calculate engine field margins for N2 and ITT by subtracting the second deltas ΔN2 and ΔITT from ΔNE field margins as an output for the outdoor power assurance check test.
12 more elements
An aircraft computer for performing an outdoor power assurance check test of a turbofan aircraft engine of an aircraft with crosswind compensation, comprising:
- at least one processor;
- at least one non-transitory storage medium having stored thereon:
- first tables representing average new engine (ΔNE) installed performance determined by running an estimated engine performance program (EEPP) to get expected values of a rotational speed of a high-speed spool (N2), an indicated turbine temperature (ITT), and combustor pressure (PB) with no deterioration and no crosswind effects;
- second tables of sensitivities of N2, ITT, and PB to high-pressure compressor (HPC) deterioration, high-pressure turbine (HPT) deterioration, and fan work scaling determined by running the EEPP;
- and
- power assurance check test instructions configured to execute on the at least one processor to:
- activate a brake of the aircraft;
- close the turbofan aircraft engine bleed system, hydraulic, and electric loads;
- bring the turbofan aircraft engine to Take-off power;
- record ambient and engine observed parameters of N2, ITT, and PB at an N1R1A once the turbofan aircraft engine is stabilized;
- bring the turbofan aircraft engine back to idle;
- calculate a difference between the engine observed parameters of N2, ITT, and PB at the N1R1A and corresponding ΔNE values of from the first tables as first deltas ΔN2, ΔITT, and ΔPB;
- using the sensitivities from the second tables and the first deltas ΔN2, ΔITT, and ΔPB, solve a 3×3 system of equations to get fan work scaling, an HPC efficiency debit, and an HPT efficiency debit;
- calculate second deltas ΔN2, ΔITT, and ΔPB to ΔNE performance without inlet bulk swirl effect using the sensitivities from the second tables and a calculated engine HPC deterioration and HPT deterioration without fan work scaling;
- and
- calculate engine field margins for N2 and ITT by subtracting the second deltas ΔN2 and ΔITT from ΔNE field margins as an output for the outdoor power assurance check test.
13 more elements
Dependencies are inferred from the claim text.