Browse Topic: Turbofan engines

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Numerical Modeling Techniques for Jet Engine Test Cell AerodynamicsAIR6355 (Current)6/5/2026
This SAE Aerospace Information Report (AIR) has been written for individuals associated with ground level testing of turbofan and turbojet engines, and particularly for those who might be interested in investigating steady-state performance characteristics of a new test cell design or of proposed modifications to an existing test cell by means of numerical modeling and simulation. It is not the intent of this standard to provide specific test cell design recommendations, which are covered in the reference documentation.
EG-1E Gas Turbine Test Facilities and Equipment
Design of Acoustical Features for a Quitter Aero-Engine Test Facility2026-26-07876/1/2026
It is a general practice to test aero engines to evaluate their performance in specially designed indoor test facilities after assembly, repaired or overhaul. Acoustic features are provided in the test facility to attenuate the noise level to a comfortable and acceptable level. Design of these features specially air intake and exhaust silencers are a challenging task in a flow field like aero-engine test facility considering the very high sound pressure level generated by them during test containing a very wide frequency band. Moreover, growing population and location of these facilities in the vicinity of residential areas has added this challenge in multifold. Also, the capital investment in building these facilities is huge due to their large size and longer construction time. Hence, the correct execution at first shot including design, fabrication and commissioning is very important. An attempt has been made to reduce design errors or improve the accuracy in the design stage by using commercially available acoustics analysis tools followed by laboratory measurement of sample features, which will reduce the lead time and cost of the project in design and implementation of the acoustic features for aero engine test facilities used for military application. This paper outlines the design of acoustics features such as air intake silencers, air cooled exhaust silencer, acoustic panels, sound proof doors and bullet resistant view window, which has produced significant improvement of noise level in and around the test facility.
Gouda, Bansidhar
Using a System Reliability Model to Optimize Maintenance Costs A Best Practices GuideJA6097_201905 (Current)5/26/2026
SAE JA6097 (“Using a System Reliability Model to Optimize Maintenance”) shows how to determine which maintenance to perform on a system when that system requires corrective maintenance to achieve the lowest long-term operating cost. While this document may focus on applications to Jet Engines and Aircraft, this methodology could be applied to nearly any type of system. However, it would be most effective for systems that are tightly integrated, where a failure in any part of the system causes the entire system to go off-line, and the process of accessing a failed component can require additional maintenance on other unrelated components.
HM-1 Integrated Vehicle Health Management Committee
A Machine Learning–Based Predictive Modeling for Optimizing the Critical Useful Life of Aeroengines: A Field Maintenance Perspective01-18-02-00096/19/2025
Establishing critical useful life plays a central role to determine aeroengine health status including aeroengine parameter changes from adverse material conditions or metal fatigue. The useful life assessment serves to support maintenance teams by enabling predictive maintenance followed by part replacement or conditions improvement. The proposed research works to improve the ability of turbofan aeroengine useful life estimation while targeting practical deployment during maintenance operations at field locations. A field maintenance–oriented ensemble bagged regression model for aeroengines represents the proposed method within this research. The present study reaches an error index of 7.06 with 98.95% model fitness when applying it to critical useful life training data. The projected model received its validation through experiments on test and field datasets. Field tests revealed that among 25 machine learning models the proposed model delivered optimal results since its error index was determined at 10.5337 with 97.60% accuracy compared to prior research findings. This study delivers an optimal solution, which enables aviation maintenance crew and techno managers to achieve effective critical useful life evaluation and decision-making for maintenance needs. This research provides essential guidance to industries under maintenance and repair operations for the reassessment of field-based critical parameters identification.
Singh, Shaktiyavesh Nandan Pratap, Shringi, Rohitashwa, Chaturvedi, Manish, Kumar, Ajay
Method for Predicting Lateral Attenuation of Airplane NoiseAIR5662 (Current)1/9/2025
This document describes analytical methods for calculating the attenuation of the level of the sound propagating from an airplane to locations on the ground and to the side of the flight path of an airplane during ground roll, climbout after liftoff, and landing operations. Both level and non-level ground scenarios may be modeled using these methods, however application is only directly applicable to terrain without significant undulations, which may cause multiple reflections and/or multiple shielding effects. This attenuation is termed lateral attenuation and is in excess of the attenuation from wave divergence and atmospheric absorption. The methods for calculating the lateral attenuation of the sound apply to: turbofan-powered transport-category airplanes with engines mounted at the rear of the fuselage (on the sides of the fuselage or in the center of the fuselage as well as on the sides) or under the wings propeller-driven transport-category or general-aviation airplanes propagation over ground surfaces that may be considered to be “acoustically soft” such as lawn or field grass situations where the terrain to the sides of the flight paths is not necessarily flat with receiver locations that are elevated above or depressed below the corresponding point on the ground under a flight path flight paths that include turns such that the airplane is banked. The calculation methods do not apply for calculation of lateral attenuation for: propagation over ground surfaces that are considered to be “acoustically hard” such as frozen or compacted soil, ice, or water propagation over ground surfaces that contain many large structures, extensive forests, and similar objects propagation over ground surfaces with significant undulating terrain the sound produced by helicopters. Helicopters are highly directional sources. While the specific method described herein is not wholly applicable to the prediction of lateral attenuation of helicopter noise, some components (see 6.1) may be applicable. Relationships presented herein were derived utilizing data from microphones placed 1.2 m above the local ground surface. The relationships may be appropriate for use at receivers at other heights, however care should be taken in such applications.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Performance Analysis of a High-Speed Tiltrotor Aircraft Featuring VerdeGo Aero's VH-5 Hybrid-Electric Turbofan EngineF-0080-2024-12355/7/2024
In the pursuit of High-Speed Vertical Takeoff and Landing (HSVTOL) platforms, VerdeGo Aero offers its VH-5 hybrid-electric turbofan as the answer to missions requiring high power, vertical lift, and jet-like speeds. To evaluate the possibility of designing a real HSVTOL aircraft around VerdeGo's VH-5 powerplant, this paper investigates the size and expected performance of a militarized spinoff of NASA's Class B, High-Efficiency Civil TiltRotor (HECTR) concept, which has been renamed the VerdeGo Hybrid-Electric Combative TiltRotor, or "VHECTR" for short. Through an in-depth conceptual weight buildup of four commonly proposed tiltrotor architectures, this paper suggests that an entirely new, turbofan-driven propulsion system is needed if modern day HSVTOL demands are to be met. Hence, a separate, yet more conventional "Modified HECTR" tiltrotor configuration is considered to contest the proposed, VH-5 powered VHECTR concept. However, the results of a full-scale aircraft comparison, aerodynamic analysis, and mission analysis alongside the V-22 Osprey indicate the VHECTR concept is more HSVTOL mission capable with greater time and fuel savings than any advanced tiltrotor system to date.
Roiati, Riccardo, Rice, Tyler, Steinfeldt, Brock, Nitzsche, Jasper, Anderson, Richard
Pratt & Whitney, Virginia Tech Pioneer Laser-Optical Approach for Turbofan Engine Thrust MeasurementTBMG-489039/1/2023
In an application first, the physics of why the sky is blue is used to measure gas flows without obstructive sensors. A longstanding industry partnership between Virginia Polytechnic Institute and State University (Virginia Tech) and Pratt & Whitney has resulted in a new laser-optical technology that aims to revolutionize in-flight thrust measurement.
NRC’s ICE-MACR 2018-2023: What Has Been Learned So Far2023-01-13776/15/2023
The Ice Crystal Environment Modular Axial Compressor Rig (ICE-MACR) was developed by the National Research Council of Canada (NRC) with support from the Federal Aviation Administration (FAA) in response to the need to understand ice crystal icing of aircraft engines at high altitudes. Icing wind tunnel tests on static hardware lack some of the real physics of turbofan compressor such as centrifuging and fracturing of particles, and melting of particles due to compression heating, heat transfer through a casing wall, as well as annular geometry effects. Since the commissioning of ICE-MACR in 2019 new insights have been gained on the physics behind ice crystal icing of turbofan engines. Additionally, the results of various test campaigns have been used to validate engine ice accretion numerical codes. This paper summarizes the key insights into ICI of turbofans gained from the ICE-MACR to date.
Neuteboom, Martin, Dumont, Christopher, Mason, Jeanne, Chalmers, Jennifer, Chow, Philip
Icing Physics Studies Using the 3D SIDRM Test Article: Aerodynamic and Supercooled Liquid Icing Analysis2023-01-13996/15/2023
In-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data is required for development of icing physics models and simulation validation. To that end, this paper presents the analysis of the supercooled liquid icing data subset from tests conducted in 2022 at the NASA Icing Research Tunnel that studied both supercooled water and ice-crystal icing. The test article that was utilized replicated 3D geometrical features of an inter-compressor duct and strut region of a turbofan engine. The surfaces of the Simulated Inter-compressor Duct Research Model (SIDRM) can be heated to simulate the warm surfaces of the turbofan inter-compressor duct. The test article is instrumented with pressure taps, heaters, heat flux gauges, and thermocouples, while a 3D laser scanner, cameras, and a scale to measure ice mass were utilized to characterize the icing behavior. The aim of these tests was to generate ice accretions on the SIDRM test article under well-characterized supercooled liquid icing and ice crystal icing conditions. This paper discusses measurements related to aerodynamic testing and supercooled liquid icing tests that were conducted. Aerodynamic measurements were analyzed and compared to computational simulations and were found to be in good agreement for the range of airspeeds (50 to 230 knots) and angles of attack (0 to 4°) tested. Various parametric sweeps were conducted during the supercooled liquid icing portion of the test entry (cloud median volumetric diameter ranged from 15 to 90 μm, total air temperature from -3 to -17 °C, angle of attack from 0 to 4°, and accretion time from 5 to 20 min). These sweeps were performed to measure that parameter’s impact on ice accretion size, location (icing extent), characteristics (such as glaze/rime ice and shedding behavior), and test article surface temperature. Analysis of the test data showed that clouds composed of larger drops, colder air temperatures, smaller angles of attack, and longer spray times were the primary parameters that resulted in accretions with greater ice mass. Test article angle of attack and cloud droplet size influenced the location of ice accretion as these two parameters directly impact collection efficiency. With respect to icing characteristics, total air temperature dictated icing type, and smaller cloud drop size along with warmer air temperatures resulted in greater amounts of ice shedding. Surface temperature increased during ice accretion from the release of latent (fusion) heat, where total air temperature and cloud drop size impacted the amount of surface temperature change. The icing measurements collected during the SIDRM tests will be used to develop and validate 3D computational engine icing tools, such as GlennICE, that predictively assesses the onset and growth of ice. One of the goals of the sponsoring NASA project is to develop simulation models and tools that can assist in the design and certification of engines for flight in icing conditions in a cost-effective way.
Bartkus, Tadas, Lee, Sam, Stewart, Eric
A Three-Layer Model for Ice Crystal Icing in Aircraft Engines2023-01-14816/15/2023
This paper presents the current state of a three-layer surface icing model for ice crystal icing risk assessment in aircraft engines, being developed jointly by Ansys and Honeywell to account for possible heat transfer from inside an engine into the flow path where ice accretion occurs. The bottom layer of the proposed model represents a thin metal sheet as a substrate surface to conductively transfer heat from an engine-internal reservoir to the ice layer. The middle layer is accretion ice with a porous structure able to hold a certain amount of liquid water. A shallow water film layer on the top receives impinged ice crystals. A mass and energy balance calculation for the film determines ice accretion rate. Water wicking and recovery is introduced to transfer liquid water between film layer and porous ice accretion layer. Numerical tests have been conducted to verify new model behaviors like substrate surface heat absorption into the accretion layer in the form of meltwater, water recovery into the film, water saturation of the accretion layer with adhesion loss and shedding risk. The proposed model, along with a new compound sticking and erosion model, is validated against selected cases from NRC’s wedge icing tests. The bouncing and erosion effect is proven crucial in the modeling. In the end, simulation of ice crystal icing within a turbofan engine at high altitude is presented. Ice crystal cloud thermodynamics have been analyzed and correlation is explained among key crystal variables like wet-bulb temperature and melt ratio. Finally, the limitations of this model are clarified.
Zhang, Yue, Narayanasamy, Karthik, Sandel, Wolfgang, Nilamdeen, Shezad, Ozcer, Isik
Computational Icing Analysis on NASA’s SIDRM Geometry to Investigate Collection Efficiency2023-01-14766/15/2023
Computational icing analysis results were compared to experimental icing tunnel data including aerothermal (e.g., dry air) and supercooled water droplet rime-ice conditions from tests conducted in early 2022 at the NASA Icing Research Tunnel (IRT). The Simulated Inter-compressor Duct Research Model (SIDRM) test article was used in this study, and its geometry represents the inter-compressor duct region of a turbofan engine. The test article’s purpose is to study the physics of supercooled water icing and ice crystal icing. This study compared three different icing codes: FENSAP-ICE (Eulerian approach), LEWICE3D (Lagrangian approach), and GlennICE (Lagrangian approach). All three icing codes were conducted on SIDRM’s complex body flow-field and compared to different experimental supercooled water rime runs. The test article instrumentation (pressure taps, thermocouples, etc.) and 3D laser scans of final ice shapes were used to compare against the different icing code simulations. The overall objectives are to understand how the icing codes handle capturing collection efficiency on the complex test article’s unheated surfaces. In the aerothermal cases, pressure tap readings matched the CFD results, but dry air CFD underpredicted thermocouple readings. Collection efficiency results from all three icing codes matched well together on the main body leading edge, main body slope, and the strut leading edges. Rime experimental collection efficiency was calculated from the raw 3D laser scan of the ice shape using a traditional equation. Results showed different matches to the icing codes at the main body nose, ramp, and strut leading edges. All three icing codes underpredicted the final ice shape using a single-shot constant ice density approach, with more difficulty coming from the strut leading edge ice shape due to the swept wing like flow field. NASA’s overall goal for this effort is to develop computational icing tools to assist in the design and certification of engines for flight in icing conditions.
Stewart, Eric, Bartkus, Tadas
Turbofan and Turbojet Gas Turbine Engine Test Cell CorrelationARP741D (Current)5/1/2023
This SAE Aerospace Recommended Practice (ARP) describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turbofan and turbojet engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. When baseline testing is performed in an indoor test cell, the baseline performance data are adjusted to open air conditions. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEM’s contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.
EG-1E Gas Turbine Test Facilities and Equipment
Uncertainty of In-Flight Thrust DeterminationAIR1678B (Current)3/23/2023
This document defines and illustrates the process for determination of uncertainty of turbofan and turbojet engine in-flight thrust and other measured in-flight performance parameters. The reasons for requiring this information, as specified in the E-33 Charter, are: determination of high confidence aircraft drag; problem rectification if performance is low; interpolation of measured thrust and aircraft drag over a range of flight conditions by validation and development of high confidence analytical methods; establishment of a baseline for future engine modifications. This document describes systematic and random measurement uncertainties and methods for propagating the uncertainties to the more complicated parameter, in-flight thrust. Methods for combining the uncertainties to obtain given confidence levels are also addressed. Although the primary focus of the document is in-flight thrust, the statistical methods described are applicable to any measurement process. The E-33 Committee has endeavoured to gather industry-wide expertise in in-flight measurement and uncertainty analysis to collect and promulgate recommended practices in the subject disciplines. The Committee is organized into subcommittees to address both the analytical and test methodology for determination of in-flight thrust and also the uncertainty of the determination. This document; Uncertainty of In-flight Thrust Determination, AIR1678, addresses the process for determining the uncertainty of in-flight thrust. A companion document, In-Flight Thrust Determination, AIR1703, addresses the basic methodology for determining in-flight thrust. The Committee, after reviewing recommended changes and clarification in definitions and application of statistical uncertainty items, made small revisions to the original document published in 1985. These changes were incorporated into AIR1678 Rev A. This Revision B has the same Scope as preceding versions. The nomenclature and methodology used herein are now consistent with evolving world and national standards promulgated primarily by ISO and ASME.
E-33 In Flight Propulsion Measurement Committee
Procedures for the Calculation of Airplane Fuel ConsumptionAIR6183 (Current)9/30/2022
This SAE Aerospace Information Report (AIR) describes procedures for calculating fuel consumption for civil jet airplanes through all modes of operation for all segments of a flight. Turboprop and piston airplanes, as well as helicopters or unconventional aircraft, are not included in this AIR. The principle purpose of these procedures is to assist model developers in calculating airplane fuel consumption in a consistent and accurate manner that can be used to address various environmental assessments including those related to policy decisions and regulatory requirements. This AIR is intended to directly support the emission calculations documented in AIR5715. The models described in this AIR are intended to be used from the start of the takeoff roll to the end of the ground roll; taxi fuel consumption models are not included. If modelers have access to higher fidelity methods, they should use those methods in lieu of the ones in this AIR.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Ultra High Bypass Ratio Engine Technology Review - The Efficiency Frontier for the TurbofanPropulsion2021-36-00322/4/2022
Turbofan engine technology has been widely used for propulsion of commercial airplanes in the subsonic range. Since the early 70's, turbofan's efficiency has greatly evolved, driven firstly by the core (thermodynamic) efficiency improvement, followed by a continuous increase in the bypass ratio (BPR), i.e. the rate between the engine fan airflow and the engine core airflow mass, with a focus on propulsive efficiency improvement. The core efficiency strategy, strongly supported on the engines' thermodynamic properties boost, i.e. using higher overall pressure ratios (OPR) and turbine inlet temperatures (TIT), has contributed decisively to the engine's thermodynamic efficiency improvement. This pathway, which required important design solutions, like engine air bleed for blade and case cooling, blade materials & coating technologies for high temperature engine components and blade tips & core clearance control, has already reached a premium performance, in which further improvement will be residual, i.e. further engine efficiency improvements must rely on other technological strategies. In parallel, the use of higher BPR, which a focus on the reduction of exhaust airflow speed and the increase in airflow mass, i.e. a lower Fan Pressure Ratio (FPR), has allowed the improvement of propulsive efficiency, hence, contributing to the overall engine's efficiency improvement. In this context, the low BPR turbofan (up to 2:1), initially used in the 70's, for commercial airliners, has evolved for the medium BPR (up to 4:1) turbofans in the 80's, large BPR (up to 8:1) in the late 90's and, finally, up to 12:1 BPR in the 2010's, have contributed to the continuous turbofan propulsive efficiency improvement. Nevertheless, the aeronautic propulsion industry, currently driven by the continuously stringent energy efficiency and environmental standards, has been encouraged to pursue additional energy efficiency and environmental performance improvements. One of the viable technological pathways, is the use of even higher BPR, with the so called Ultra High Bypass Ratio (UHBPR) engine approach, which uses BPR higher that 13:1 and can be seen as the turbofan engine efficiency frontier, to be used as a promising technology for near future airplane propulsion. Despite the propulsive efficiency improvements, the increase in the BPR sets some technological challenges in the engine design, associated with an increase in the engine's aerodynamic drag and weight (due to the larger fan&nacelle diameters), fan and core engine aerodynamics stability control, as well as aerodynamic engine and airframe & lifting devices integration issues. This paper presents an overview of the UHBPR engine technology and its inherent technological challenges, with a focus on the engine architecture and the required technological tools, such as geared fans, swept & twisted inlet vanes, variable pitch fan, variable fan nozzle area, required to circumvent the associated aerodynamic and mechanical operational limitations.
Barbosa, Fábio Coelho
An Assessment of Planar WavesAIR5866A (Current)2/1/2021
“An Assessment of Planar Waves” provides background on some of the history of planar waves, which are time-dependent variations of inlet recovery, as well as establishing a hierarchy for categorizing various types of planar waves. It further identifies approaches for establishing compression-component and engine sensitivities to planar waves, and methods for accounting for the destabilizing effects of planar waves. This document contains an extensive list and categorization (see Appendix A) of references to aid both the newcomer and the practitioner on this subject. The committee acknowledges that this document addresses only the impact of planar waves on compression-component stability and does not address the impact of planar waves on augmenter rumble, engine structural issues, and/or pilot discomfort.
S-16 Turbine Engine Inlet Flow Distortion Committee
Design Considerations for Enclosed Turbofan/Turbojet Engine Test CellsAIR4869B (Current)2/1/2021
This SAE Aerospace Information Report (AIR) has been written for individuals associated with the ground-level testing of large and small gas turbine engines and particularly for those who might be interested in upgrading their existing or acquiring new test cell facilities.
EG-1E Gas Turbine Test Facilities and Equipment
Methods of Controlling Distortion of Inlet Airflow During Static Acoustical Tests of Turbofan Engines and Fan RigsAIR1935A (Current)12/22/2020
This Aerospace Information Report provides guidelines for hardware design. Guidelines on such items as engine types, test arrangements, and test purposes that would benefit from the use of an inflow control device during static noise testing are outside the scope of this report.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Measurement of Far Field Noise from Gas Turbine Engines During Static OperationARP1846B (Current)12/21/2020
Recommendations presented in this document are intended primarily for the acquisition of far-field noise data. The test engine is to be appropriately configured and operated so that the sound pressure levels obtained are consistent with the specific objectives of the test. The principal output of the data reduction system is one-third octave band sound pressure levels. However, when appropriate, data may be recorded for purposes of broader or narrower bandwidth analysis.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Design Considerations for Enclosed Turbofan/Turbojet Engine Test CellsAIR4869A (Historical)10/22/2020
This SAE Aerospace Information Report (AIR) has been written for individuals associated with the ground-level testing of large and small gas turbine engines and particularly for those who might be interested in upgrading their existing or acquiring new test cell facilities.
EG-1E Gas Turbine Test Facilities and Equipment
Test Cell InstrumentationAIR5026B (Current)10/21/2020
This document discusses, in broad general terms, typical present instrumentation practice for post-overhaul gas turbine engine testing. Production engine testing and engine development work are outside the scope of this document as they will typically use many more channels of instrumentation, and in most cases will have requirements for measurements that are never made in post-overhaul testing, such as fan airflow measurements, or strain measurements on compressor blades. The specifications for each parameter to be measured, in terms of measurement range and measurement accuracy, are established by the engine manufacturers. Each test cell instrument system should meet or exceed those requirements. Furthermore, each instrument system should be recalibrated regularly, to ensure that it is still performing correctly.
EG-1E Gas Turbine Test Facilities and Equipment
Optimal Sizing and Control of Battery Energy Storage Systems for Hybrid Turboelectric Aircraft2020-01-00503/10/2020
Hybrid-electric gas turbine generators are considered a promising technology for more efficient and sustainable air transportation. The Ohio State University is leading the NASA University Leadership Initiative (ULI) Electric Propulsion: Challenges and Opportunities, focused on the design and demonstration of advanced components and systems to enable high-efficiency hybrid turboelectric powertrains in regional aircraft to be deployed in 2030. Within this large effort, the team is optimizing the design of the battery energy storage system (ESS) and, concurrently, developing a supervisory energy management strategy for the hybrid system to reduce fuel burn while mitigating the impact on the ESS life. In this paper, an energy-based model was developed to predict the performance of a battery-hybrid turboelectric distributed-propulsion (BHTeDP) regional jet. A study was conducted to elucidate the effects of ESS sizing and cell selection on the optimal power split between the turbogenerators (TGs) and ESS. To this extent, the supervisory energy management strategy is formulated into a discrete time optimal control problem and solved via dynamic programming. The performance of BHTeDP was compared to a turboelectric distributed-propulsion (TeDP) next-gen aircraft that assumes improvements in weight, drag, and engine efficiency consistent with regional jet entering operation in 2035.
Sergent, Aaronn, Ramunno, Michael, D'Arpino, Matilde, Canova, Marcello, Perullo, Christopher
Implementation and Comparison of Model Co-Simulation Methods in a Turbofan Model2020-01-00033/10/2020
The process of developing, parameterizing, validating, and maintaining models occurs within a wide variety of tools, and requires significant time and resources. To maximize model utilization, models are often shared between various toolsets and experts. Model integration is typically divided into two categories: model exchange and model co-simulation. Of these two categories, model co-simulation is typically regarded as the more complex and difficult to implement. Co-Simulation provides the ability to integrate models between different toolsets or incompatible versions of the same software. Additionally, it provides the capabilities for real-time simulations and hardware-in-the-loop test scenarios. This paper reviews some of the common co-simulation data communication methods including pipes and file input/output. The differences between serial and parallel, aka synchronous and asynchronous, communication patterns are also discussed. A simple turbofan model was developed to demonstrate the aforementioned methods. The turbofan model was developed in a legacy version of NPSS, and this legacy model was integrated with a high-fidelity turbine model developed in a newer version of the NPSS software. The integration of the legacy turbojet model with the high-fidelity turbine is used to demonstrate how to integrate two models between incompatible software versions. This application can readily be extended to other co-simulation scenarios, such as real-time simulation. Integration of the two models was implemented using the aforementioned communication methods, synchronization mechanisms, and communication patterns. Relevant implementation details for the turbojet/turbine application are described, and a detailed discussion of the results and comparisons between different methods is provided.
Krouse, Charles, Nelson-Weiss, Brendan
Aircraft Engine Technology Review - The Pathways for an Efficient, Cleaner and Quieter Aviation Industry2019-36-01751/13/2020
The aviation industry has been submitted to a set of environmental and commercial drivers that have led it to pursue engine technologies focused on the efficiency improvement, greenhouse (CO2) and pollutant (NOx and PM) emissions reductions, as well as noise abatement.The effort to comply with the ambitious long term environmental and efficiency targets set by the regulatory authorities has driven the aeronautic industry in a technological research effort. In the medium term, the aviation industry's strategy for commercial aviation is to focus on the advanced, but rather conventional propulsion systems (mainly turbofan engines). In this scenario, technological efforts have focused basically on enhancing thermal efficiency, through advanced core engines, as well as improving propulsive efficiency, through the use of low pressure systems (basically reduced pressure ratio and increased engine bypass ratio). To reach these objectives, a set of technological platforms has been proposed, with some already on an operational/commercial level, while others still in a prototype category. In this context, engine manufacturers have given a special focus on some technological approaches, like Ultra High Bypass Ratio (UHBPR) Geared Turbofans (GTF), Three Spool Turbofan (3STF), Counter-Rotating Open Rotor (CROR), Intercooled Turbofan (ITF) and Bleedless Engine (BE). This work is supposed to present, into a review format, an overview of the aforementioned technology platforms, demonstrating their potential to meet the efficiency and environmental requirements, their maturity level, as well as report any cases of operational experience available in the technical literature.
Barbosa, Fábio Coelho
Design and Implementation of Digital Twin for Predicting Failures in Automobiles Using Machine Learning Algorithms2019-28-015910/11/2019
The drastic technological advancements in the field of autonomous vehicles and connected cars lead to substantial progression in the commercial values of automobile industries. However, these advancements force the Original Equipment Manufacturers (OEMs) to shift from feedback-based reactive business analysis to operational-data based predictive analysis thereby enhancing both the customer satisfaction as well as business opportunities. The operational data is nothing but the parameters obtained from several parts of an automobile during its operation such as, temperature in radiator, viscosity of the engine oil and force applied over the brake disk. These operational data are gathered using several sensors implanted in different parts of an automobile and are continuously transmitted to backend computers to develop Digital Twin, which is a virtual model of the physical automobile. Later, gathered operational data are analyzed using data mining algorithms to predict the failures of an automobile well in advance, better insights into performance of an automobile thereby recommending alternative design choices and remote service management of failures by a professional technician. Firstly, this research work illustrates the platform for the creation of digital twin using Eclipse Hono, Eclipse Kura and Eclipse Ditto. Secondly, it explains about the operational data gathering and processing at the nearby edge devices as well as the remote cloud. Finally, the prediction of failures is demonstrated using Turbofan Engine Degradation Simulation Dataset by means of several machine learning regression algorithms and compare their accuracies. Finally, it is concluded that Gradient Boost Regressor provides better accuracy in predicting future failures.
Balakrishnan, Ponnuraman, Ramesh Babu, Kalivaradhan, Naiju, Chooriyaparambil Damodaran, Madiajagan, Muthaiyan
Landing Gear Integration into Aircraft Structure in Early Design Stage2019-01-18909/16/2019
The demanded development towards various emission reduction goals set up by several institutions forces the aerospace industry to think about new technologies and alternative aircraft configurations. With these alternative aircraft concepts, the landing gear layout is also affected. Turbofan engines with very high bypass ratios could increase the diameter of the nacelles extensively. In this case, mounting the engines above the wing could be a possible arrangement to avoid an exceedingly long landing gear. Thus, the landing gear could be shortened and eventually mounted at the fuselage instead of the wings. Other technologies such as high aspect ratio wings have an influence on the landing gear integration as well. To assess the difference, especially in weight, between the conventional landing gear configuration and alternative layouts a method is developed based on preliminary structural designs of the different aircraft components, namely landing gear, wing and fuselage. Simplified parametric finite element structural models for the different components are introduced. These models are used to investigate different aircraft configurations with special regard on the landing gear integration. The structural models of the fuselage and the wing are sized according to defined load cases. After this first sizing step, the structural model of the landing gear is integrated and different landing gear load cases are applied. The developed methods aim to assess the impact of the different landing gear configurations, not only regarding the landing gear structure but also the surrounding support structure of the airframe. Results of the applied methods for aircraft configurations with different landing gear integration are presented and discussed.
Kling, Ulrich, Hornung, Mirko
Test Cell Analytical Thrust CorrectionAIR5436A (Current)7/2/2019
This document describes a method to correct engine thrust, measured in an indoor test cell, for the aerodynamic effects caused by the secondary airflow induced in the test cell by the engine operating in an enclosed environment in close proximity to an exhaust duct. While it is not recommended to be used to replace test cell correlation, it does provide a means to verify an existing thrust correlation factor.
EG-1E Gas Turbine Test Facilities and Equipment
Ice Crystal Icing Test Design and Execution for the ALF502 Vane Segment in the NRC RATFac Cascade Rig2019-01-19256/10/2019
Understanding the behaviour of ice crystal ice (ICI) accretion and shedding inside an aircraft engine is important for safe and reliable engine operation in flight and to meet new airworthiness regulations. A significant advancement in this understanding came from two engine test campaigns carried out on a Honeywell ALF502 turbofan, led by the Ice Crystal Consortium (ICC) and NASA. However, it is often desirable to conduct smaller scale component level tests to both decrease costs and increase the amount of data obtainable, given a component is more accessible when removed from an engine and therefore easier to instrument and observe. That was the purpose of the work discussed in this paper where a segment of an ALF502 low pressure exit guide vane ring was installed in the NRC RATFac ICI cascade rig. The existing cascade rig was modified to accommodate the vane segment which allowed for the instrumentation already available on the rig to be used to characterize the ICI environment. The test article fixturing was designed to match the engine aerodynamics as much as possible but also allow for a large suite of instrumentation including temperatures, pressures, video, ultrasound ice accretion sensors and systems for wall heating and anti-icing. The test was able to characterize accretion versus a wide range of ICI conditions, determine the effect of wall heating and define accretion boundaries. With the wide range of test parameters that were independently and precisely controlled and the instrumentation available to measure them, the understanding of accretion in the vane segment was expanded relative to that seen in the engine test. Accretion was seen on the test article in the location observed in the engine with similar morphology. Further analysis of the test data could demonstrate the added value of a rotating rig test.
Fuleki, Dan, Neuteboom, Martin, Chalmers, Jennifer
Semi-Empirical Modelling of Erosion Phenomena for Ice Crystal Icing Numerical Simulation2019-01-19676/10/2019
The aim of this work is to develop a semi-empirical model for erosion phenomena under ice crystal condition, which is one of the major phenomena for ice crystal accretion. Such a model would be able to calculate the erosion rate caused by impinging ice crystals on accreted ice layer. This model is based on Finnie [1] and Bitter [2] [3] solid/solid collision theory which assumes that metal erosion due to sand impingement is driven by two phenomena: cutting wear and deformation wear. These two phenomena are strongly dependent on the particle density, velocity and shape, as well as on the surface physical properties such as Young modulus, Poisson ratio, surface yield strength and hardness. Moreover, cutting wear is mostly driven by tangential velocity and is more effective for ductile eroded body, whereas deformation wear is driven by normal velocity and is more effective for brittle eroded body. Several researchers based their erosion modelling on these two phenomena such as Hutchings et al. [4] for deformation erosion, or Huang et al. [5] and Arabnejad et al. [6] for cutting and deformation erosion. The main work of this paper is to develop an erosion model for ice crystal impingement based on these two phenomena, and to show its capability to predict accretion shape by simulating experimental cases from the National Research Council of Canada (NRC). NRC’s Currie et al. ice crystal experiments [7] [8] realized in warm aerodynamic conditions, such as the one encountered in high icing severity areas of a turbofan engine, show accretion severity for a large range of liquid water content to total water content. In order to validate the erosion model based on solid/solid collision, this paper presents the simulation of the lower melting rate experiment. Results show fair agreement with experimental data and allow us to propose pertinent further work.
Charton, Virgile, Trontin, Pierre, Aouizerate, Gilles, Villedieu, Philippe
Scaling Evaluation of Ice-Crystal Icing on a Modern Turbofan Engine in PSL Using the COMDES-MELT Code2019-01-19206/10/2019
This paper presents preliminary ice-crystal icing (ICI) altitude scaling evaluation results of a Honeywell Uncertified Research Engine (HURE) that was tested in the NASA Glenn Research Center Propulsion Systems Laboratory (PSL) during January of 2018. This engine geometry features a hidden core design to keep the core less exposed. The engine was fitted with internal video cameras to observe various ice buildup processes at multiple selected locations within the engine core flow path covering the fan stator, the splitter-lip/shroud/strut, and the high pressure compressor (HPC) variable inlet guide vane (IGV) regions. The potential ice accretion risk was pre-determined to occur by using NASA’s in-house 1D Engine Icing Risk assessment code, COMDES-MELT. The code was successful in predicting the risk of ice accretion in adiabatic regions like the fan-stator of the HURE at specific engine operating points. However at several operating points during the test, liquid water was observed running along the shroud toward the variable IGV of the HPC regions with an air temperature well below freezing, thus no particle melting could have occurred due to heating from the air alone. It was reasoned that other sources of heat were present in that region. To account for these heat sources the inlet total temperature was adjusted to give a wet bulb temperature of 24 °F below the standard minimum wet bulb temperature of 492 °R to allow ice to accrete in the splitter-lip/shroud/strut region, which was determined from a reference case where hard ice was observed in that region. With that adjustment the COMDES-MELT code was successful in providing operating points where there was a risk of ice accretion during the test campaign. In addition to calculating possible conditions at different selected lower altitudes, simulations were run to determine potential inlet conditions that could lead to ice-crystal accretion along the prescribed stations where the cameras were available. From there, scaled test conditions were determined by best matching the following three icing related parameters of the reference condition: (1) the local air total wet bulb temperature, (2) the local ice crystal cloud melt ratio and (3) the engine fan face ice/water to air mass flux ratio of the ice crystal cloud. Instantaneous images taken from the time-lapsed movies of ice buildup were used along with the relevant thermodynamic data of air, water vapor and local icing condition to help evaluate how closely the proposed altitude scaling method could be used in ground based test facility to duplicate selected reference ICI features observed at specific location inside this engine at different scale altitudes. Discussions on observed limitation for engine icing scaling application from this test campaign and needed improvement are provided. A scaling test procedure to help identify potential ICI risk conditions and possible ice accretion locations of a new turbofan engine is evaluated in PSL.
Tsao, Jen-Ching
Microwave Technique for Liquid Water Detection in Icing Applications2019-01-19306/10/2019
The partial melting of ingested ice crystals can lead to ice accretion in aircraft compressors, but accurately measuring the relatively small fraction of liquid water content in such flows is challenging. Probe-based methods for detecting liquid water content are not suitable for deployment within turbofan engines, and thus alternatives are sought. Recent research has described approaches based on passive microwave sensing. We present here an approach based on active microwave transmission and reflection, employing a vector network analyzer. Utilization of both transmission and reflection provides additional data over and above emission or transmission only, and permits a more controllable environment than passive sensing approaches. The paper specifically addresses the question of whether such an approach is viable within the context of representative icing wind tunnel and engine flow conditions. A quasi-thermal equilibrium approach is presented herein to estimate the melting ratio during microwave analysis of samples at 0 °C. Experimental results using microwaves in the 2.45GHz region are presented, and post-processing methods investigated. This is followed by an investigation of detection limits for ice accretion in the sub-gram range. The results indicate the potential of the technique, with a number of avenues evident for further research.
Leis, John, Buttsworth, David, Saeed, Ramiz, Saleh, Khalid, McGilvray, Matthew, Gillespie, David
Wind Tunnel Measurements of Simulated Glaciated Cloud Conditions to Evaluate Newly Developed 2D Imaging Probes2019-01-19816/10/2019
Instrumentation that has been used for characterization of mixed-phase and glaciated conditions in the past, like the OAP probes, are subject to errors caused by variations in diffraction on the images away from the object plane and by the discrete nature of their particle detection and sizing. Correction methods are necessary to consider their measurements adequate for high ice water content (IWC) environments judged to represent a significant safety hazard to propellers and turbofan engine operability and performance. For this reason, within the frame of EU FP7 HAIC project, instrumentation characterization and validation is considered a major element need for successful execution of flight tests campaigns. Clearly, instrumentation must be sufficiently reliable to assess the reproducibility of artificial clouds with high ice water content generated in icing tunnels. Instruments are required to measure these conditions with a sufficient level of accuracy for the purposes of the testing. Currently, there is an anticipated basic uncertainty of a factor of 2-5 when measuring clouds in-situ. This may be worse for thunderstorm core regions, because of the poorly measured ice particle sizes below 100 μm when using legacy instruments. Measurements below 100 μm are especially difficult for ice particles. In order to mitigate this measurement limitation, an innovative approach for imaging droplets and ice crystals was considered in this work. This method is based on Artium Technologies Inc. High Speed Imaging (HSI) instrument. The method utilizes a unique multi-beam illumination approach to control the depth of field, minimize out-of-focus image noise effects, and limit obscuration of particles in the sample volume produced by out-of-focus particles in the optical path. Rather than utilizing a linear array to acquire the images, a modern CMOS two-dimensional array imaging system is used. The lasers used for producing bright field shadow images are pulsed synchronously and have pulse duration of as little as 12.5 ns to “freeze” the particle motion. The response of the HSI will be reviewed on the basis of comparison with SPEC 2D-S by means of wind tunnel measurements for glaciated cloud conditions.
Esposito, Biagio M., Bachalo, William D., Leroy, Delphine, Schwarzenboeck, Alfons, Jurkat, Tina, Voigt, Christiane, Bansmer, Stephan
The Effect of Crosswinds on Icing at Turbofan Engine Inlet2019-01-20246/10/2019
Ice accretion at engine inlet has a dangerous effect on the inlet airflow and shed ice would be ingested into the engine and cause compressor blades damage, and even combustors flame out. In order to analyze the effect of crosswinds on icing at turbofan engine inlet, a complete icing analysis method, which is based on the Messinger model and takes the influence of runback water into consideration, is constructed. The runback water is considered laminar flow and the flow direction is dominated by the bottom flow of air. The supercooled water droplets impingement, ice accretion and runback water characteristics and inlet distortion with and without ice were investigated at crosswinds speed of 15, 20, 25, 30 kt. The variation of local water collection coefficient β is unchanged at crosswind conditions, but the location of the maximum value and non-dimensional impact limits change with the crosswind, which move backward along the outer edge on the windward, and move along the inner edge on the leeward. The ice thickness on windward surface increases slightly near the stagnation point, and the outer icing limit occurs at more rear position with crosswinds. On leeward surface, the variation is opposite to the windward and the ice shapes present a more symmetrical distribution at stagnation point. On the smooth inlet surface, the inlet airflow at the fan is relatively uniform, and the total pressure ratio variation at the inlet lip also is regular as crosswind increases. Greatly losses of airflow occur after ice accretion at crosswind conditions, which cause uneven inlet airflow. The effect of the crosswind on ice accretion at the inlet should be considered when designing and optimizing anti-icing system. Otherwise, the ice formation under crosswind will deteriorate the inlet airflow quality and pose a hazard to aircraft safety.
Yang, Qian, Guo, Zhiqiang, Zheng, Mei, Dong, Wei
Design of Composite Materials for Improved Loss-of-Lubrication Survivability of Hybrid Rotorcraft GearsF-0075-2019-146855/13/2019
Hybrid gears featuring steel teeth mated to a composite body provide the potential for significant weight savings in aerospace applications such as rotorcraft and geared turbofan engines. For hybrid gears to be viable for use in these applications, they must not degrade mechanical performance or thermal characteristics, particularly under loss-of- lubrication operation. The heat generated by loss-of-lubrication operation may be especially problematic for the fiber- reinforced polymer composite materials used in hybrid steel-composite gear prototypes. Initial hybrid gear design and testing is described in the literature, but no prior studies have investigated optimization of the composite material for thermal performance. In the study presented herein, conductive fibers and high-temperature polymers are introduced to make a composite material better suited to high-temperature and loss-of-lubrication. Channel-flow resin transfer molding was used to fabricate composites with a variety of configurations, including hybrid reinforcement alternating highly-conductive pitch-based carbon fiber plies with typical high-strength polyacrylonitrile (PAN)-based carbon fiber plies. Performance was evaluated by thermal conductivity measurement and compression strength testing. Finite element modeling was performed to quantify strength and stiffness requirements for the composite gear web and to investigate the effects of using plies of different stiffness in a hybrid laminate. Results of this study show that the in-plane thermal conductivity of composite laminates can be greatly increased by using hybrid reinforcement, but the hybrid gear web design must account for the low compression strength of the hybrid reinforcement to ensure that the structural integrity of the composite gear web is not compromised.
Waller, Matthew, Koudela, Kevin, McIntyre, Sean
Diagnostics and Prognostics of Aerospace EnginesPT-19511/28/2018
The propulsion system is arguably the most critical part of the aircraft; it certainly is the single most expensive component of the vehicle. Ensuring that engines operate reliably without major maintenance issues is an important goal for all operators, military or commercial. Engine health management (EHM) is a critical piece of this puzzle and has been a part of the engine maintenance for more than five decades. In fact, systematic condition monitoring was introduced for engines before it was applied to other systems on the aircraft. Diagnostics and Prognostics of Aerospace Engines is a collection of technical papers from the archives of SAE International, which introduces the reader to a brief history of EHM, presents some examples of EHM functions, and outlines important future trends. The goal of engine health maintenance is ultimately to reduce the cost of operations by catching problems before they become major issues, by helping reduce repair times through diagnostics, and by facilitating logistic optimization through prognostic estimates. Diagnostics and Prognostics of Aerospace Engines shows that the essence of these goals has not changed over time.
Rajamani, Ravi
Acoustical Considerations for Engine Test CellsARP5759 (Historical)11/21/2018
This document discusses, in broad and general terms, the subject of acoustical considerations in engine test cells. One of the primary purposes of an engine test cell is to control the noise emanating from the operating engine in order to reduce noise in the surrounding facility and community to acceptable levels. This is done by the design and installation of specialized acoustic elements and features, which need to be fully integrated into the overall test cell design. It should be further noted, that the requirements of acoustic control are critical to the proper operation of the engine, safety of plant equipment and personnel, and meeting local and legal noise requirements.
EG-1E Gas Turbine Test Facilities and Equipment
Novel Turboelectric Aircraft DesignTBMG-288615/1/2018
NASA Langley Research Center has developed a novel aircraft design that can carry 150+ passengers over a range of 3,500 nautical miles. Key features include a turboelectric propulsion system, twin underwing turbofans, and a rear-fuselage, electrically driven, boundary layer ingesting fan. The design is developed for single-aisle-class aircraft (the largest commercial transport class in the world) to significantly reduce fuel burn compared to current aircraft.
Variable Bypass Turbofan EngineTBMG-288775/1/2018
Many aircraft need to operate efficiently at more than one flight regime; for example, certain airframes are expected to perform in relatively high-speed cruise modes, as well as slower loitering scenarios. Unfortunately, an engine operates most efficiently when the exit velocity closely matches the speed of the airframe. As a result, designing an engine that is suitable for multiple roles yields an engine that only performs moderately well in each of those operating conditions.
Axial Magnetic Flux Airflow Integrated Compressor-Generator-Motor Turbojet DesignTBMG-287074/1/2018
Innovators at the NASA Armstrong Flight Research Center have developed a compressor-generator-motor turbojet design concept that integrates the generator with the aerodynamic blade structures of the compression section of turbomachinery. This reduces weight and volume compared with conventional turbine generator arrangements in which the turbojet or turbofan drives a separate shaft-driven generator. All conventional turbomachinery designs suffer from some type of system inefficiencies: Conventional side-mounted generators add the weight of a 90-degree gearbox; a rear-mounted generator is difficult to cool. The Armstrong design improves existing configurations with a flight-weight electromagnetic turbo-generator that is suitable for application to distributed turboelectric systems on aircraft, and aids in cooling the system. This technology may enable new aircraft configurations and future TurboElectric Distributed Propulsion (TeDP) aircraft designs.
Infrasound Phenomenon in Engine Test CellsAIR5303 (Historical)1/4/2018
This SAE Aerospace Information Report (AIR) has been written for individuals associated with the ground level testing of large turbofan and turbojet engines, and particularly those who are interested in infrasound phenomena.
EG-1E Gas Turbine Test Facilities and Equipment
Installed Outdoor Engine TestingAIR5301A (Historical)11/29/2017
This SAE Aerospace Information Report (AIR) was written because of the growing interest in aircraft installed outdoor engine testing by the Federal Aviation Administration, airlines, charter/commercial operators, cargo carriers, engine manufacturers and overhaul and repair stations. This document was developed by a broad cross section of personnel from the aviation industry and government agencies and includes information obtained from a survey of a variety of operators of fixed and rotary wing aircraft and research of aircraft and engine maintenance manuals.
EG-1E Gas Turbine Test Facilities and Equipment
Assessment of the Inlet/Engine Total Temperature Distortion ProblemAIR5867 (Historical)11/21/2017
This report revises ARD50015 document to the AIR format. This report, as was the original, is intended to complement ARP1420C and AIR1419C documents issued by the SAE S-16 Committee on spatial total-pressure distortion. These previous documents addressed only total-pressure distortion and excluded total temperature distortion. The subject of inlet total temperature distortion is addressed in this report with some background and identification of the problem area. The status of past efforts is reviewed, and an attempt is made to define where we are today. Deficiencies, voids, and limitations in knowledge and test techniques for total temperature distortion are identified.
S-16 Turbine Engine Inlet Flow Distortion Committee
F-16 UpgradesTBMG-274979/1/2017
Saft Levallois-Peret, France +33 1 58 63 16 00 www.saftbatteries.com
Turbofan Engine Acoustic Liner Design and Analysis ToolsTBMG-268665/1/2017
NASA Langley Research Center has developed two tools for turbofan engine acoustic liner design and analysis. The first is a statistical approach for broadband liner design and assessment; the second is graphical software to design and analyze resonant channels in acoustic liners.
Test Cell Thrust MeasurementAIR4951 (Historical)2/13/2017
Thrust measurement systems come in many sizes and shapes, with varying degrees of complexity, accuracy and cost . For the purposes of this information report, the discussions of thrust measurement will be limited to axial thrust in single-axis test systems.
EG-1E Gas Turbine Test Facilities and Equipment
Gas Turbine Engine Test Facility Vibration MeasurementARP6068 (Historical)2/9/2017
EG-1E Gas Turbine Test Facilities and Equipment
Physical Modeling Techniques for Jet Engine Test Cell AerodynamicsAIR4827B (Historical)10/21/2016
This SAE Aerospace Information Report (AIR) has been written for individuals associated with ground level testing of turbofan and turbojet engines and particularly for those who might be interested in investigating the performance characteristics of a new test cell design or of proposed modifications to an existing test cell by means of a scale model test.
EG-1E Gas Turbine Test Facilities and Equipment
High-Speed Edge-Detecting Circuit for Use with Linear Image SensorTBMG-251388/1/2016
A new smart camera developed at NASA’s Glenn Research Center has the ability to process and transmit valuable edge location data for the images that it captures — at a rate of over 900 frames per second. The camera was designed to operate as a component in an inlet shock detection system for supersonic jets. A supersonic jet cannot function properly unless the airflow entering the machine is compressed and slowed to subsonic speed in the inlet before it reaches the engine. When supersonic air is compressed, it forms shock waves that can destroy the turbofan and surrounding components unless they are pinpointed and adjusted. This smart camera uses an edge detection signal processing circuit to determine the exact location of shock waves, and sends the location information via an onboard microcontroller or external digital interface. This highly customizable camera’s ability to quickly identify precise location data makes it ideal for a variety of other applications where high-speed edge detection is needed.
Ground testing begins on the GE9X16MEIP06_086/1/2016
In mid April, ground testing began on the first full GE9X development engine at GE Aviation's Peebles Testing Operation in Ohio. The GE9X engine will power Boeing's new 777X aircraft. According to Bill Millhaem, General Manager of the GE90/GE9X engine programs at GE Aviation, “The ground testing will generate data on the full engine system and aerodynamic performance, mechanical verification, and aero thermal system validation.” Maturation testing of the GE9X turbofan engine began about five years ago and has progressed from component-level all the way to the recent first full engine to test (FETT). FETT brings all the GE9X technologies together to demonstrate their operability as a complete propulsion system.
Broge, Jean L.
Prognostic Metrics for Engine Health Management SystemsAIR5909 (Historical)2/26/2016
This SAE Aerospace Information Report (AIR) presents metrics for assessing the performance of prognostic algorithms applied for Engine Health Management (EHM) functions. The emphasis is entirely on prognostics and as such is intended to provide an extension and complement to such documents as AIR5871, which offers information and guidance on general prognostic approaches relevant to gas turbines, and AIR4985 which offers general metrics for evaluating diagnostic systems and their impact on engine health management activities.
E-32 Aerospace Propulsion Systems Health Management
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