Browse Topic: Aircraft propulsion systems
This SAE Aerospace Standard (AS) provides a performance station designation system for aircraft propulsion systems and their derivatives
This AIR describes the current scientific and engineering principles of gas turbine lubricant performance testing per AS5780 and identifies gaps in our understanding of the technology to help the continuous improvement of this specification. Test methodologies under development will also be described for consideration during future revisions of AS5780
This SAE Aerospace Information Report (AIR) provides an overview of temperature measurement techniques for various locations of aircraft gas turbine engines while focusing on current usage and methods, systems, selection criteria, and types of hardware
This paper explores the groundbreaking applications of plasma propulsion engines and advanced nanomaterials in low-altitude aircraft, addressing the challenges and recent technological advancements that make such applications feasible. Traditional space plasma thrusters operate effectively in near-vacuum conditions by taking advantage of the ease of plasma ignition at low pressures. However, these thrusters face significant difficulties when operated at near-atmospheric pressures found in low-altitude environments, where plasma ignition is challenging. This paper highlights recent breakthroughs in high-pressure plasma glow discharge technology and the integration of nanomaterials, which together enable the use of plasma propulsion engines in low-altitude aircraft. These innovations offer substantial advantages over conventional engines, including higher efficiency, reduced emissions, and the potential to fundamentally change the propulsion systems of low-altitude aircraft
SABERS, as this portfolio of innovations is named, refers to Solid-state Architecture Batteries for Enhanced Rechargeability and Safety. Developed jointly at NASA’s Glenn, Langley and Ames Research Centers, SABERS includes several advanced material, manufacturing and computational design innovations that enable a new paradigm in battery performance. The primary target application is next-generation electric aviation propulsion systems, yet SABERS will benefit other applications, too
This SAE Standard establishes the requirements for lubricating oils containing ashless dispersant additives to be used in four-stroke cycle, reciprocating piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-22851. Users should consult their airframe or engine manufacturer’s manuals for the latest listing of acceptable lubricants. Compliance with this specification must be accomplished in accordance with the Performance Review Institute (PRI) product qualification process as described in the documents referenced in 2.1.3. Requests for submittal information may be made to the PRI at the address shown in 2.1.3, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Approval and/or certification for use of a specific piston engine oil in aero applications is the responsibility of the individual equipment builders and/or governmental
This standard defines the minimum requirements for conducting Measurement Systems Analysis (MSA) for variable and attribute assessment on characteristics as defined on the drawing or specification. It does not define the detailed analytical methods for each type of study as these can be found in existing published texts (see Section 2 for guidance
This SAE Standard establishes the requirements for non-dispersant lubricating oils to be used in four-stroke cycle piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-6082. Users should consult their airframe or engine manufacturers’ manuals for the latest listing of acceptable lubricants. Compliance with this specification must be accomplished in accordance with the Performance Review Institute (PRI) product qualification process as described in the documents referenced in 2.2.2. Requests for submittal information may be made to the PRI at the address shown in 2.2.2, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Approval and/or certification for use of a specific piston engine oil in aerospace applications is the responsibility of the individual equipment builders and/or governmental authorities and may be accomplished
This procedure is intended to apply to fuel pumps. This procedure will be defined in terms of recommended test fluid, test setup, test conditions, and test method. This procedure may be used for other fuel system components, by testing in conjunction with the pump, which normally supplies the component inlet flow, or a substitute test pump of similar capacity. This procedure may be used, with variations in test conditions and test fluid, for performing pump evaluation tests. Tests at progressively increasing pump speeds and pressures will provide design limitation data. Alternate test periods on a test pump and another pump, of a design for which actual service durability is known, will provide useful comparison data
The mystery of how futuristic aircraft embedded engines, featuring an energy-conserving arrangement, make noise has been solved by researchers at the University of Bristol. University of Bristol, Bristol, UK A study published in Journal of Fluid Mechanics, reveals for the first time how noise is generated and propagated from these engines, technically known as boundary layer ingesting (BLI) ducted fans. BLI ducted fans are similar to the large engines found in modern airplanes but are partially embedded into the plane's main body instead of under the wings. As they ingest air from both the front and from the surface of the airframe, they don't have to work as hard to move the plane, so it burns less fuel. The research, led by Dr. Feroz Ahmed from Bristol's School of Civil, Aerospace and Design Engineering under the supervision of Professor Mahdi Azarpeyvand, utilized the University National Aeroacoustic Wind Tunnel Facility. They were able to identify distinct noise sources originating
A Gerotor pump is a positive displacement pump consisting of inner and outer rotors, with the axis of inner rotor offset from axis of outer rotor. Both rotors rotate about their respective axes. The volume between the rotors changes dynamically, due to which suction and compression occurs. Due to their high-speed rotations, a Gerotor pump may be subjected to erosion due to cavitation. This paper details about the Computational Fluid Dynamics (CFD) based methodology that has been used to capture cavitation bubbles, which might form during the operation of Gerotor pump and to identify the erosion zone which might be occur due to cavitation bubble getting burst near the surface layers of the gears. A full scale (3D) transient CFD model of a Gerotor pump has been developed using commercial CFD code ANSYS FLUENT. The most challenging part of this CFD flow modeling is to create a dynamic volume mesh that perfectly represents the dynamically changing rotor fluid volume of the Gerotor pump
The test method describes the procedure for the direct determination of water concentration in polyol ester and diester based aerospace lubricants by commercially available automated coulometric Karl Fischer titration instruments. The method was validated to cover the water concentration range of 150 to 3500 µg/g. The method may also be suitable for the determination of water concentrations outside this range and for other classes of fluids; however, the precision statement shall not be applicable for such uses
The process detailed within this document is generic and applies to the entire end-to-end health management capability, covering both on-board and on-ground elements, in both commercial and military applications throughout their lifecycle. This ARP addresses a gap in guidance related to usage of ground-based health management equipment for airworthiness credit, ensuring a level of integrity commensurate with the potential aircraft-level consequences of the relevant failure conditions. The practical application of this standardized process is detailed in the form of a checklist. The on-board elements described here are typically the source of the data acquisition used for off-board analysis. The on-board aspects relating to airworthiness and/or safety of flight, e.g., pilot notification, are addressed by existing guidance and policy documents. If a proposed health management capability for airworthiness credit involves modification of the on-board systems, the substantiation of those
This specification covers a neopentyl polyol ester fluid (see 8.2) with AS5780 HPC or MIL-PRF-23699 HTS Class performance
SAE Aerospace Recommended Practice ARP1533 is a procedure for the analysis and evaluation of the measured composition of the exhaust gas from aircraft engines. Measurements of carbon monoxide, carbon dioxide, total hydrocarbon, and the oxides of nitrogen are used to deduce emission indices, fuel-air ratio, combustion efficiency, and exhaust gas thermodynamic properties. The emission indices (EI) are the parameters of critical interest to the engine developers and the atmospheric emissions regulatory agencies because they relate engine performance to environmental impact. While this procedure is intended to guide the analysis and evaluation of the emissions from aircraft gas turbine engines (burning conventional hydrocarbon based liquid fuels), the methodology may be applied to the analysis of the exhaust products of any hydrocarbon/air combustor. Some successful applications include: Aircraft engine combustor development rig tests (aviation jet fueled) Stationary source combustor
The test method describes the procedure for determination of the total acid number (TAN) of new and degraded polyol ester and diester-based gas turbine lubricants by the potentiometric titration technique. The method was validated to cover an acidity range of 0.05 to 6.0 mg KOH g-1. The method may also be suitable for the determination of acidities outside of this range and for other classes of lubricants
The flight area of drones and other unmanned aerial vehicles (UAVs) had been highly restricted but has been relaxing, including flights beyond the scope of sight. Deregulation without aircraft-reliability improvement increases the risk of accidents. However, demanding high reliability for all aircraft leads to an increase in the price of the aircraft. Therefore, if airspace restrictions are relaxed for more reliable aircraft, the cost of higher reliability and its benefits can be balanced. This will improve efficiency and optimize cost-effectiveness. The purpose of this proposal is to balance the cost of aircraft-reliability improvement (which allows flight to continue in the event of a failure) and its advantages. Specifically, the author proposes rules that apply more relaxed airspace restrictions to UAVs with higher FCLs (Flight Continuity Possibility Levels) and stricter airspace restrictions to those with lower FCLs. The FCL does not only refer to the distance or time that can be
Boom Supersonic, the company building supersonic planes, is developing Symphony, a new propulsion system designed and optimized for its Overture supersonic airliner. Boom will be teaming with three industry leaders to develop Symphony including Florida Turbine Technologies (FTT) for engine design, GE Additive for additive technology design consulting, and StandardAero for maintenance
This SAE Aerospace Information Report (AIR) provides methodologies and approaches that have been used to install and integrate full-authority-digital-engine-control (FADEC) systems on transport category aircraft. Although most of the information provided is based on turbofan/turboprop engines installed on large commercial transports, many of the issues raised are equally applicable to corporate, general aviation, regional, and commuter aircraft, and to military installations, particularly when commercial aircraft are employed by military users. The word “engine” is used to designate the aircraft propulsion system. The engine station designations used in this report are shown in Figures 1 to 3. Most of the material concerns an electronic engine control (EEC) with its associated software and its functional integration with the aircraft. However, the report also addresses the physical environment associated with the EEC and its associated wiring and sensors. Since most current transport
The confidence of the onboard adaptive model in estimating surge margin significantly affects the operating stability in an aircraft engine’s active surge margin control process. Unfortunately, the existing onboard adaptive models lack high confidence, although wide-ranging in estimation, due to the unknown surge boundaries in component characteristics. Therefore, this paper first accurately estimates the actual surge margin during the engine operating near-surge boundary using a pressure correlation measurement technology. Then, innovatively, the estimated surge margin is used to correct the surge boundary of the nonlinear onboard model of the engine to obtain the actual surge boundary, thereby guaranteeing confidence. Finally, a nonlinear onboard adaptive model based on an improved spherical unscented Kalman filter is employed to achieve wide-range high-confidence surge margin estimation throughout the engine’s life cycle. Simulation results demonstrate that the proposed method is
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
A team of MIT engineers is creating a one-megawatt motor that could be a key stepping-stone toward electrifying larger aircraft. The team has designed and tested the major components of the motor and has shown through detailed computations that the coupled components can work as a whole to generate one megawatt of power — at a weight and size competitive with current small aero-engines
In 2014, Airbus made history when it introduced a small metal bracket through additive manufacturing (AM) to secure an engine on one of its commercial jetliners. This milestone marked the beginning of an era of innovation in aerospace, pushing the boundaries of technology. The journey from that first AM experiment to today's transformative landscape in the aerospace and defense industries has been nothing short of remarkable. The capabilities of AM have redefined the sector, offering unprecedented efficiencies and reshaping how we understand and approach manufacturing. Aerospace and defense has emerged as a trailblazer in the adoption of AM. While aerospace and defense AM demand was negatively impacted during the COVID-19 pandemic, the global aerospace and defense additive manufacturing market is projected to grow from $3.73 billion in 2021 to $13.01 billion in 2028
This document defines the process steps involved in collecting and processing engine test data for use in understanding engine behavior. It describes the use of an aero-thermal cycle model for reduction and analysis of those data. The analysis process may include the calculation of modifiers to match the model to measured data and prediction of engine performance based on that analysis
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