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Technical Paper
Silvia Marelli, Giulio Marmorato, Massimo Capobianco, Jean-Maxime Boulanger
Turbocharging is playing today a fundamental role not only to improve automotive engine performance, but also to reduce fuel consumption and exhaust emissions for both Spark Ignition and diesel engines. Dedicated experimental investigations on turbochargers are therefore necessary in order to get a better understanding of its performance. The availability of experimental information on realistic turbine steady flow performance is an essential requirement to optimize engine-turbocharger matching calculations developed in simulation models. This aspect is more noticeable as regards turbine efficiency, since its swallowing capacity can be accurately evaluated through the measurement of mass flow rate, inlet temperature and pressure ratio across the machine. Actually, in the case of a turbocharger radial inflow turbine, isentropic efficiency directly evaluated starting from measurement of thermodynamic parameters at the inlet and outlet sections can give significant errors.
Technical Paper
Jan Macek, Oldrich Vitek
The ever increasing boost pressure demands and seek for low CO2 emissions call for high efficiency turbochargers, which are perfectly matched to an engine and controlled in operation, especially if highly diluted mixture is used. Correct turbocharger representation, usually performed by maps, should be delivered by turbocharger manufacturers and applied in simulation optimizations. Recently, a broad discussion has been taking place in engine designers’ community on possibilities of measurement of isentropic efficiencies at a turbocharger testbed using hot gas for a turbine. Simultaneously, concepts of high-pulsation exhaust manifolds and asymmetrical turbine scrolls are re-introduced. The paper elucidates the relations between apparent and real turbocharger isentropic efficiencies at steady-flow testbed and their impact on engine cycle optimization by simulation. The hints for a turbocharger representation may be deduced from it. Error analysis starts the explanation.
WIP Standard
No scope available.
WIP Standard
This SAE Aerospace Recommended Practice (ARP) addresses the characteristics required for the definition, development, and acquisition of a satisfactory airframe mounted accessory gearbox (AMAG).
WIP Standard
This document provides a review of published methods that have been used to provide estimates of the levels of distortion and/or the concomitant loss of stability pressure ratio that can occur when the recommended full complement of aerodynamic interface plane high-response instrumentation is not used when obtaining inlet data. The methods have been categorized based on the underlying mathematical representation of the aerophysics. Further, the use of maximum value statistics, which has been used to further improve the results where short- duration time records have been employed, is discussed.
WIP Standard
This SAE Aerospace Information Report (AIR) provides a methodology for performing a statistical assessment of gas-turbine-engine stability-margin usage. Consideration is given to vehicle usage, fleet size, and environment to provide insight into the probability of encountering an in-service engine stall event. Current industry practices, such as ARP1420, supplemented by AIR1419, and engine thermodynamic models, are used to determine and quantify the contribution of individual stability threats. The statistical technique adopted by the S-16 committee for performing a statistical stability assessment is the Monte Carlo method (see Applicable References 1 and 2). While other techniques may be suitable, their application is beyond the scope of this document. The intent of the document is to present a methodology and process to construct a statistical-stability-assessment model for use on a specific system and its mission or application.
WIP Standard
Scope is unavailable.
WIP Standard
This AIR will address the need for a strategy to achieve aircraft operating certificate holder maintenance efficiencies within the existing regulatory environment as well as the need for regulation, policy, and guidance changes in the long-term to accommodate more complex IVHM solutions. This document will analyse which IVHM solutions can be incorporated within existing maintenance procedures and which also comply with regulations, policy, and guidance. One of the AIR’s objectives is to define best practices for aircraft operating certificate holders to engage with regulators to get approval for simpler IVHM applications leading to maintenance efficiencies. Additionally, this document will analyse the barriers that existing regulations, policy, and guidance present to the implementation of more advanced IVHM solutions. The result is a set of recommendations to certify and implement end-to-end IVHM solutions for the purpose of gaining maintenance efficiencies.
WIP Standard
The goal of this new document is to provide criteria for managing, auditing, and controlling the use of rotating balancing tooling and associated support tools. A variety of subjects will be addressed including serialization and marking requirements, critical inspection criteria, performance tracking through tooling compensation trend analysis, handling of gage standards (rotor simulators, master blades, dummy blades, etc.), recommendations for periodic and preventive maintenance intervals, test recommendations to evaluate rotating tooling performance, requirements for traceable measures (such as torques, runouts, eccentricity, etc.), repeatability characterization, and criteria for return to service.
This Aerospace Recommended Practice (ARP) is a general overview of typical airborne engine vibration monitoring (EVM) systems applicable to fixed or rotary wing aircraft applications, with an emphasis on system design considerations. It describes EVM systems currently in use and future trends in EVM development. The broader scope of Health and Usage Monitoring Systems, (HUMS) is covered in SAE documents AS5391, AS5392, AS5393, AS5394, AS5395, AIR4174. This ARP also contains the essential elements of AS8054 which remain relevant and which have not been incorporated into Original Equipment Manufacturers (OEM) specifications.
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