Browse Topic: Auxiliary power units

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A Methodology for Assessing Inlet Swirl DistortionAIR5686 (Current)7/31/2026
This Aerospace Information Report (AIR) addresses the subject of aircraft inlet-swirl distortion. A structured methodology for characterizing steady-state swirl distortion in terms of swirl descriptors and for correlating the swirl descriptors with loss in stability pressure ratio is presented. The methodology is to be considered in conjunction with other SAE inlet distortion methodologies. In particular, the combined effects of swirl and total-pressure distortion on stability margin are considered. However, dynamic swirl, i.e., time-variant swirl, is not considered. The implementation of the swirl assessment methodology is shown through both computational and experimental examples. Different types of swirl distortion encountered in various engine installations and operations are described, and case studies which highlight the impact of swirl on engine stability are provided. Supplemental material is included in the appendices. This AIR is issued to bring together information and ideas required to address the inlet-swirl problem for which common industry practice has yet to be established. This document should foster the tests and analyses necessary to mature the ideas proposed by the committee to a recommended practice. These tests and analyses must include information that justifies three main features of the proposed swirl methodology: (1) swirl descriptors for correlating inlet swirl and stability pressure ratio loss, (2) computational techniques for analyzing compression systems (inlets, fans, compressors), and (3) test protocols (instrumentation and test techniques). The committee anticipates serving the industry by using such information to establish the consensus necessary for issuance of an SAE recommended practice.
S-16 Turbine Engine Inlet Flow Distortion Committee
Performance Analysis of a Gasoline Direct-Injection Opposed-Piston FPEG: A Coupled Study of Injection, Scavenging, and Dynamics2026-01-50637/28/2026
The opposed-piston free-piston engine generator (FPEG) is a promising high-efficiency energy conversion architecture, featuring reduced heat transfer and favorable NVH characteristics for applications such as auxiliary power units and vehicle range extenders. While significant progress has been made, existing studies often focus on isolated parameters. The coupled effects of key operational parameters, including injection pulse width, scavenging pressure, rebound cylinder base pressure, and mover mass, on the performance of gasoline direct-injection opposed-piston FPEG remain insufficiently explored. To bridge this gap, we develop and validate a thermodynamics zero-dimensional combustion simulation model against bench tests, with peak pressure errors below 5%. This model enables a systematic investigation into the interactive effects of these parameters. Results indicate that piston dynamics are most sensitive near dead centers and in the first half of the expansion stroke. Indicated thermal efficiency peaks at 35.87% with a 4.5 ms injection pulse width and increases from 35.02% to 36% as scavenging pressure rises from 1.3 bar to 3 bar. Scavenging pressure dominates compression ratio and efficiency, rebound pressure mainly affects operating frequency, and injection width governs indicated work and peak pressure. This study establishes a coupled analysis framework, providing concrete insights for optimizing opposed-piston FPEG performance through parameter coordination.
Wu, Limin, Ji, Kaixuan, Feng, Huihua, Jia, Boru, Zuo, Zhengxing
Battery Thermal Management Approach for Two-Wheeler Electric Vehicles – An Indian Case Study2026-26-01511/16/2026
India's electric 2-wheeler (E2W) market has witnessed fast growth, driven by lucrative government policies. The two-wheeler segment dominates the Indian automotive market, accounting for the largest share of total sales. Consequently, the manufacturers of 2-wheelers are developing new electric vehicles (EV) tailored for the Indian market. However, the Indian EV market has witnessed multiple fire accidents in recent years, raising safety concerns among consumers and industry stakeholders. These incidents highlight key weakness in battery thermal management systems (BTMS), particularly during charging. Most existing E2W BTMS relies on passive (natural) air cooling, which has been associated with fire incidents due to its inefficiency in heat dissipation, particularly during charging in India's high-temperature environment. Therefore, it is imperative to build thermally viable and economical BTMS for the growing E2W vehicles with fast charging capability. FEV is actively developing the thermally efficient and cost-effective BTMS solutions tailored for Indian E2Ws operating in extreme climatic conditions. The present study evaluates a novel approach of integrating heat carrier plates into the E2W with 3.6 kWh battery pack, which is analyzed under natural and forced air cooling system. The airtight battery pack is located under the floorboard region. The multiple internal heat carrier plates models are developed and integrated with aligned and staggered cell arrangement to evaluate heat dissipation and temperature uniformity with the battery pack. The study further proposes a concept of duct and fan placement for the application during forced air cooling. The simulations are performed at a high ambient temperature of 45 °C, representing a worst-case scenario in India, using charging rates of 0.2 C for natural cooling and 0.35 C for forced cooling. The results show that the aligned cell model with 4-heat carrier plates achieve superior temperature distribution across cells, with a lower average module temperature of 49.6 °C, minimal temperature gradient of 1.3°C and reduced maximum cell temperature of 50 °C, under natural cooling. In forced air-cooling mode, the split air duct model provides better cooling over the battery cover surfaces with maximum temperature of 55 °C with ΔT of 4°C. The study also presents comprehensive details of modelling approaches and outlines the scope of further research for developing thermally efficient BTMS for E2Ws.
Raut, Ankit, Hiremath, Vinodkumar S, Emran, Ashraf, Garg, Shivam, Berry, Sushil
Functional Safety of Electric or Hybrid Off-Highway Vehicles – An Embedded Software Viewpoint2025-28-021711/6/2025
To provide growing needs of food, clothing and infrastructure for growing population of the world, off-highway vehicles such as those in construction, agriculture and commercial landscaping are moving towards electrification for enhanced precision, productivity, efficiency and sustainability. It has also paved a way to adopt autonomy of these vehicles to address challenges like skilled labor shortage for timely and efficient execution. Despite the tremendous advantages of electrification, be it through completely replacing engines in vehicles or efficiency improvements using hybrid architecture for powertrain and auxiliary power demands, safety remains a significant challenge and critical requirement for off-highway electric vehicles. This paper explains the concept and importance of functional safety in electric off-highway vehicles, and shows how different standards like ISO 26262, ISO 25119, ISO 13849 can be utilized to achieve state of the art in functional safety for different off-highway applications. It focusses on functional safety processes, tools and analysis of electrification components like inverters responsible for control of off-highway vehicle transmission and other functions from an embedded software point of view. It also discusses how the functional safety goals drive the embedded software and hardware requirements, and eventually verification and validation. It will provide an overview of software architecture concepts, control and safety mechanisms and their purpose to avoid and detect failures or faults in the vehicle and take appropriate actions.
Mujumdar, Chaitanya Gajanan, Bachhav, Kiran, Deshpande, Chinmay
Off-Highway Electrification: A Case Study beyond Propulsion and Emission2025-28-022311/6/2025
To provide needs of food, clothing and infrastructure for growing population of the world, off-highway vehicles such as those in construction, agriculture and commercial landscaping are moving towards electrification for enhanced precision, productivity, efficiency and sustainability. It has also paved way to adopt autonomy of these vehicles to address challenges like skilled labour shortage for timely and efficient execution. There are many challenges and opportunities of electrification in off-highway domain, be it through completely replacing engine in vehicles or efficiency improvements using hybrid architecture for powertrain and auxiliary power demands, electrification being key enabler precision and speed of the complex operations, automation of complex operation. This paper explains the need of electrification in electric off-highway vehicles and shows how the electrification solves the current challenges faced by off-highway heroes like farmers, construction site owners and workers, commercial lawn and golf turf owners and workers, etc. It first discusses the challenges faced by this industry in terms of scarcity of skilled labour, changing weather conditions, operator fatigue and ever-increasing pressure of productivity, uptime and cost. Then paper presents why electrification is key to solve these issues and how increasing adoption of such technologies becomes relevant.It further explains some architecture/application case studies in farm equipment to cater needs of complex operations like crop care and harvesting, manoeuvring through different soils, lands as well as doing repeated and complex operations at construction sites and other type of off-highway applications like oil fracking industry, trucks, mining, etc.. This case studies describe how electrification has directly enabled more productivity through speed and precision, less operator fatigue, fuel efficiency, farm input efficiency and has become enabler for autonomy.
Deshpande, Chinmay Vasudev, Mujumdar, Chaitanya, Bachhav, Kiran
Thermodynamic Exergy Analysis of PEMFC Systems for System Efficiency and Waste Heat Recovery2025-28-035210/30/2025
Proton Exchange Membrane Fuel Cell (PEMFC) vehicles are emerging as a promising green alternative to fossil fuel and battery-operated electric vehicles. Fuel cells convert the chemical energy of fuel to direct current (DC) through electrochemical reactions, rejecting some heat in the process. This study aims to minimize heat generated during these reactions within the fuel cell stack and utilize it to enhance stack efficiency. Through thermodynamic modeling and exergy analysis, the research focuses on reducing waste heat from exothermic reactions in PEMFC stacks. It investigates using low-temperature waste heat for heating hydrogen and inlet air also examining into how stoichiometry and current density influence heat reduction. Analytical studies were carried out using air stoichiometry ranging from 1.5 to 2 and ambient temperatures typical of Bangalore's climate (15°C to 35°C). The results show that increasing the current density from 1 A/cm2 to 1.5 A/cm2 significantly raises the hydrogen power requirement and stack power output, however, it leads to a decrease in overall system efficiency, from 57% to 49%, due to higher exergy losses. In addition, as ambient temperature rises from 288.15 K to 308.15 K, reduces the overall efficiency of the system, primarily due to higher auxiliary power consumption. Cathode stoichiometry also plays a crucial role, increasing stoichiometry from 1.5 to 2 resulting in higher compressor power consumption and more waste heat generation. Furthermore, Auxiliary parts like heat exchangers and air compressors require a significant amount of power in which emphasizes the need for system optimization. Heating inlet gases with hot cooling water can boost system efficiency by 1% and save around 2.7 kW of energy. System efficiency could be substantially enhanced by effectively utilizing the stack's waste heat.
Sahu, Tomesh Kumar, Bansode, Annasaheb
Integrated Modeling and Optimization Design of EMU Based on MBSE2025-99-007110/17/2025
As the core transportation tool of high-speed railroad, the design, and optimization of EMU is the current research hotspot. This paper aiming to improve design efficiency, optimize performance parameters. From the perspective of vehicle level, based on the requirements and operation scenarios of the whole vehicle, according to the RFLP method, combined with the SysML and M-design, we conduct the vehicle requirements analysis, functional decomposition, architecture analysis, whole vehicle index system establishment, and the auxiliary power supply(APU) system is calculated by the parameters, the battery design is optimized by PSO. The results show that integrated modeling makes the interface between systems clearer and improves the model reuse rate; the performance design and parameter optimization quantify the modeling indicators, the system energy consumption is lowered, and the closed-loop verification of requirements is realized, which is of some value to the refined design of other systems.
Guan, Lin, Wang, Baomin, Wang, Qingyong, Zhou, Lujie, Wan, Keyan
Ammonia Combustion with Ignition Improvement Measures in a High-Speed Marine Application2025-24-00259/7/2025
Ammonia (NH3) has gained significant attention as a zero-carbon fuel which is capable of supporting global decarbonization goals, especially in the maritime transportation and power generation sectors. Its hydrogen density, storage feasibility, established production methods, and transportation infrastructure are key benefits which contribute to its potential both as a hydrogen carrier and as a direct fuel. The study investigates the combustion characteristics and emission profiles of ammonia on a spark ignited 2.13L single cylinder engine with the goal of evaluating ammonia as a single fuel. This displacement is representative of the typical cylinder displacement of small to mid-size engines for marine applications on sportfishing boats and as auxiliary power units. Challenges to consider for ammonia combustion are its high ignition energy requirement and low laminar flame velocity. Several methods were employed to compensate for these properties such as increasing compression ratio, the use of a passive pre-chamber spark plugs, and the use of hydrogen in a dual fuel set-up. The experimental results demonstrate stable combustion of 100 % ammonia under homogenous stoichiometric condition. NOX emissions reach typical levels of SI engines, around 8 – 12 g/kWh. Meanwhile, a certain level of NH3 emissions are unavoidable and require a customized exhaust aftertreatment. Up to 45 % indicated efficiency have been reached. The evaluation of the combustion enhancement techniques shows clearly that the higher CR, the use of a pre-chamber spark plug as well as the addition of a small hydrogen share all significantly reduce the burn delay and speed up the combustion considerably. Moreover, the NH3/NOX ratio in the exhaust gas is directly affected by these techniques which have relevance for the operation of an SCR aftertreatment system.
Li, Zhengling, Lückerath, Moritz, Pischinger, Stefan, Boberic, Aleksandar, Franzke, Bjoern, Dhongde, Avnish, Jagodzinski, Bartosch, Burrows, John, Korkmaz, Metin
Impact of Hybrid Electric Vehicles on Energy Consumption and Emission Reduction for Agricultural Applications2025-01-85404/1/2025
As the agricultural industry seeks to enhance sustainability and reduce operational costs, the introduction of mild hybrid technology in tractors presents a promising solution. This paper focuses on downsizing internal combustion (IC) engine, coupled with integration of electric motor, to reduce fuel consumption and meet stringent emission regulations while maintaining power requirement for agricultural applications in India. The hybridization aims to deliver instant power boosts during peak loads and capitalizes on energy recovery during part loads and braking. Furthermore, the idle avoidance feature minimizes fuel consumption during periods of inactivity thus improving fuel efficiency. The hybridization also aims to hybridize auxiliary systems for flexible power management, enabling operation of either engine, auxiliaries, or both as needed. A newly developed hybrid supervisory control prototype efficiently manages electric power and mechanical power, enabling intelligent management of auxiliary power consumption. This approach eliminates belt-driven mechanical loads, allowing auxiliaries to operate independently and on-demand, thus optimizing performance and fuel efficiency. Virtual simulations of hybrid electric tractor were conducted to assess the impact of intelligent auxiliary management on vehicle performance and fuel consumption, as detailed in this paper. The findings indicate that adopting such technologies in agricultural machinery not only enhances operational efficiency but also aligns with global efforts towards sustainable farming practices. This paper advocates for continued research and development in hybrid technologies to further advance the agricultural sector's transition towards environmentally friendly solutions.
Prasad, Lakshmi P., PS, Satyanarayana, Paygude, Tejas, Gangsar, Purushottam, Thakre, Mangesh, Choudhary, Nagesh, Gitapathi, Ajinkya
A Multifunctional Integrated Three-Level Inverter and On-Board Charger for Electric Vehicle Application2025-01-85674/1/2025
This paper presents a highly integrated 4-in-1 power electronics solution for 800V electric vehicle applications, combining on-board charging (OBC), DC boost charging, traction drive, and high-voltage/low-voltage (HV/LV) power conversion in a single housing. Integration is achieved through the use of motor windings for charging and a custom-designed three-port transformer that magnetically couples HV and LV batteries while ensuring galvanic isolation. The system also employs a three-phase open-ended winding machine (OEWM) to support both single-(1P) and three-phase (3P) AC charging. A dual-bank DC/DC architecture allows for seamless integration of a redundant auxiliary power module (APM), enhancing functional safety and autonomy. In AC charging mode, the three-level (3L) T-type inverter operates as a Vienna rectifier for 3P charging and as a totem-pole power factor correction (PFC) circuit for 1P charging, with the motor windings utilized as PFC inductors. In DC boost charging mode, the 3L inverter functions as a boost converter, stepping up the 400V DC input to the 800V battery. A triple active bridge (TAB) converter facilitates HV-to-HV and HV-to-LV DC/DC conversion and also functions as a Dual Active Bridge (DAB) during boost charging and traction modes. In traction mode, the T-type 3L inverter drives the motor. Finally, the system is benchmarked against conventional non-integrated designs, demonstrating significant improvements in cost, volume, and weight.
Wang, Yicheng, Taha, Wesam, Anand, Aniket
Auxiliary Power Unit Electrical Interface Requirements for Class Eight TrucksJ2891_202502 (Current)2/8/2025
This SAE Recommended Practice covers the design and application of a 120 VAC single phase engine based auxiliary power unit or GENSET. This document is intended to provide design direction for the single phase nominal 120 VAC as it interfaces within the truck 12 VDC battery and electrical architecture providing power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off.
Truck and Bus Electrical Systems Committee
Aircraft Propulsion System Performance Station DesignationAS755G (Current)12/5/2024
This SAE Aerospace Standard (AS) provides a performance station designation system for aircraft propulsion systems and their derivatives.
S-15 Gas Turbine Perf Simulation Nomenclature and Interfaces
DC-DC Converters for High Reliability eVTOL Auxiliary Power SystemsTBMG-5214712/1/2024
Air Conditioning Systems for Subsonic AirplanesARP85G (Current)10/3/2024
This SAE Aerospace Recommended Practice (ARP) contains guidelines and recommendations for subsonic airplane air conditioning systems and components, including requirements, design philosophy, testing, and ambient conditions. The airplane air conditioning system comprises that arrangement of equipment, controls, and indicators that supply and distribute air to the occupied compartments for ventilation, pressurization, and temperature and moisture control. The principal features of the system are: a A supply of outside air with independent control valve(s). b A means for heating. c A means for cooling (air or vapor cycle units and heat exchangers). d A means for removing excess moisture from the air supply. e A ventilation subsystem. f A temperature control subsystem. g A pressure control subsystem. Other system components for treating cabin air, such as filtration and humidification, are included, as are the ancillary functions of equipment cooling and cargo compartment conditioning. The interface with the major associated system, the pneumatic system (Chapter 36 of ATA 100) is at the inlet of the air conditioning shutoff valves. This boundary definition aligns with that in the ATA 100 Specification.
AC-9 Aircraft Environmental Systems Committee
Cooling of Military Avionic EquipmentAIR1277B (Current)10/3/2024
This SAE Aerospace Information Report (AIR) contains information on the thermal design requirements of airborne avionic systems used in military airborne applications. Methods are explored which are commonly used to provide thermal control of avionic systems. Both air and liquid cooled systems are discussed.
AC-9 Aircraft Environmental Systems Committee
Minimization of Power Consumption in Fuel Cell Air Feed in System in Fuel Cell Electric Vehicle2024-28-00569/19/2024
The air supply system in a Fuel Cell Electric Vehicle (FCEV) provides the oxygen needed for the fuel cell to react with hydrogen. The air compressor, being the main component of the air supply subsystem, has the highest power consumption among all auxiliary loads in an FCEV. Therefore, efficient control of the air supply system is critical for improving fuel cell performance. The air supply system has a slow response to dynamic load changes. Due to its weak transient response, an overshoot in airflow can lead to an increase in auxiliary power loss, while an undershoot can cause a delay in meeting power requirements. Thus, reducing transients is a crucial factor in improving the overall system efficiency. In conventional control, the battery supplies additional power needed during dynamic load changes. During high dynamic load changes, there is frequent switching between the battery and the fuel cell. This frequent charging and discharging of the battery can impact its longevity. Currently, the control of the air compressor in the fuel cell is reactive. The proposed solution aims to reduce the losses in the air compressor by predictively tuning the gain parameters of the controller and optimizing the power split between the fuel cell stack and the battery using the predicted vehicle load. Predictive tuning helps in reducing transients in fuel cell air compressor control, ensuring smooth power transfer and minimal losses due to the air system. The proposed method uses the topography ahead information and other vehicle parameters to estimate the load. The air compressor model, coupled with predictive and adaptive tuning, suggests the controller parameters that minimize the air system losses. The switching strategy between the fuel cell stack power and battery power takes the dynamics in predicted load changes into consideration.
Choubey, Ayush, Ponangi, Babu Rao, Shah, Saurabh, Munirajappa, Chandrashekara
Electrifying Vocational Trucks: An Overview of Advancements and Challenges in Electric and Hybrid Powertrains with Emphasis on Auxiliary Power Considerations2024-24-00059/18/2024
Electric and hybrid powertrains are steadily gaining popularity, showcasing their efficacy in reducing greenhouse gas emissions and pollution, particularly in urban environments. This also applies to medium and heavy-duty vocational trucks. Truck manufacturers have been expanding their electrified portfolio and some of them have already announced their plans to phase out fossil fuels. Vocational trucks are essential for the industry of commercial vehicles, represent an extremely heterogeneous class, and are often upfitted by third-party companies. In general, vocational trucks are designed for specific jobs. Typically, they are driven on short routes, but they may work for longer hours in comparison to freight transportation vehicles. Most importantly, among the broad category of vocational trucks, some vehicles greatly exploit power take-offs to drive auxiliary systems, like refuse trucks, utility trucks, cement trucks, and sweeper trucks. The benefits resulting from the kinetic energy regeneration of urban driving are undeniable and well-documented in several studies. Electrified short-haul, delivery, and box vocational trucks are indeed becoming widely accepted, but the auxiliaries of these trucks do not need a significant amount of energy. In this regard, few studies analyze the effect of auxiliary loads, even if they may require significant power and cause considerable drifts in energy consumption estimation. Indeed, velocity-based driving cycles are commonly used to assess the energy savings of electrified powertrains, but they only focus on analyzing the power needed for traction purposes. By focusing on vocational trucks that greatly rely on power take-offs and auxiliary power flows, this study shows an overview of the existing advancements in electric and hybrid vocational trucks, drawing on both academic and industrial instances, while explaining their different needs. Finally, this study analyzes efforts from both academia and industry to generate standardized duty cycles that can be used to assess the energy consumption of medium and heavy-duty vocational trucks, avoiding the need to replicate unique duty cycles that are measured on specific vehicles and environments.
Beltrami, Daniele, Villani, Manfredi, Iora, Paolo, Rizzoni, Giorgio, Uberti, Stefano
Measurement of Exterior Noise Produced by Aircraft Auxiliary Power Units (APUs) and Associated Aircraft Systems During Ground OperationARP1307C (Current)5/24/2024
Test procedures are described for measuring noise at specific receiver locations (passenger and cargo doors, and servicing positions) and for conducting general noise surveys around aircraft. Procedures are also described for measuring noise level at source locations to facilitate the understanding and interpretation of the data. Requirements are identified with respect to instrumentation; acoustic and atmospheric environment; data acquisition, reduction and presentation, and such other information as is needed for reporting the results. This document makes no provision for predicting APU or component noise from basic engine characteristics or design parameters, nor for measuring noise of more than one aircraft operating at the same time. No attempt is made to suggest acceptable levels of noise or suitable subjective criteria for judging acceptability. ICAO Annex 16 Volume I Attachment C provides guidance on recommended maximum noise levels.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
A Real-Time Predictive Fuzzy Energy Management Based on Speed Prediction for Range Extended Electric Logistics Vehicle2024-01-27854/9/2024
Due to the complexity and timeliness of the dual power source control system for range extended electric vehicles, a real-time predictive fuzzy energy management strategy based on speed prediction, which comprehensively takes into account the demand power of auxiliary power unit, future average speed and driving distance is proposed in this work. Firstly, to improve the topicality and accuracy of the control system, the convolutional neural network with long short-term memory neural network (CNN-LSTM) algorithm is adopted to predict the future driving speed by the speed features and adjacent speeds. Secondly, taking account of the characteristics of the driving conditions for electric logistics vehicles, a three-inputs-one-output fuzzy controller is formulated based on the average predicted speeds, current traveling distance and demand power of the auxiliary power unit, so as to adjust the expected output power to harmonize the fuel consumption, electricity costs for the process of battery charging, discharging and degradation. Besides, the comparative tests are carried out to validate the effectiveness of various control strategies for harmonizing fuel consumption and battery degradation. The results under the World Light-duty Vehicle Test Cycle (WLTC) indicate that compared with the fuzzy control strategy which only takes the current vehicle speed as an input variable and the charge-depleting charge-sustaining (CD/CS) strategy, the total operation cost of the proposed strategy is reduced by 3.04% and 34.44%, respectively. Finally, The robustness and effectiveness of the strategy are verified under various driving conditions, and the real-time performance of the strategy is verified by HIL experiment. Hence, the proposed real-time predictive fuzzy energy management strategy gives out the great control effect on economy improvement and suppression of battery decay for electric extended-range vehicles.
Yang, Bingjun, Chen, Yong, Chen, Guang, Lin, Xiaozhe, Wei, Changyin, Liu, Caixia
Impact of Automated Driving on Design and Energy Consumption of Electrified Drives2024-01-21584/9/2024
This paper discusses the dependency between powertrain design and automated driving. The research questions are to what extent automated driving influences the powertrain design and how energy and fuel consumption is affected in comparison to customer driving. For this investigation a concept study is carried out for a D-segment vehicle and multiple powertrain topologies, ranging from non-electrified to plug-in hybrids and battery electric vehicles. In order to answer the research questions, the used development process and the methods for optimizing the drive system are presented accordingly, taking into account all vehicle requirements, the drive system and the components and their interactions with each other. This work focuses on two automated driving functions developed at the Institute of Automotive Engineering of the Technische Universität Braunschweig. The functions are an “automated valet parking” and a “highway pilot”. The hardware architecture required for automated driving functions lead to an increase in vehicle mass and auxiliary power consumption. Furthermore, the automated driving functions result in changed driving profiles. Driving cycles were generated on the basis of measurement data from the automated functions and compared with the customer's driving operation. The results show, that an energy reserve for an automated valet parking function leads to a reduction in the all-electric range up to 12 km for battery electric vehicles and 7 km for plug-in-hybrids and thus also to up to 2 g/km higher combined emissions. It has also been shown that the impact of the highway pilot to energy and fuel consumption in customer operation is significantly influenced by the customer's driving style and the additional consumption for the automated driving function, with battery electric vehicles having the highest savings potential.
Sturm, Axel Wolfgang, Henze, Roman, Küçükay, Ferit
An Operating Point Adjustment Model Using PMP-GWO-Bi-LSTM for RANGE Extended Electric Vehicle2023-01-702010/30/2023
The increasingly severe energy problems and environmental pollution have imposed severe requirements on the fuel saving level of vehicles. The range extender configuration is a tandem structure that has attracted more and more researchers’ attention due to its architectural features and control methods. An intelligent APU operating point adjustment model based on PMP-GWO-Bi-LSTM is proposed in this paper to enhance adaptability to real driving conditions for the traditional optimal strategy. Firstly, a PMP model has been applied into a range extended electric vehicle model from which the optimized power distribution data under several standard driving cycles was recorded as the input to deep learning model. Secondly, a Bi-LSTM model fed by control parameters and power distribution data was established and trained using aforementioned datasets. The aim is to learning the nonlinear regression relationship model between APU control variables and power distribution. Furthermore, the GWO optimization algorithm is introduced to optimize the hyperparameter of Bi-LSTM to speed up the running speed of the model and improve accuracy. Finally, the experiment was conducted using real driving condition data to predict the power distributions. The simulation results show APU overall efficiency improvement by 15.87% whilst fuel consumption improved by 9.42%. The number of hyper parameters such as the iterations and hidden layer units using GWO optimization algorithm is 35.50% and 38.38% less and the training time decreases by 4.61 s, which proves that the model proposed in this paper can achieve good result in real driving conditions.
Huang, Wei, Zhang, Yujun, Qian, Duode, Hu, Biqian
PRODUCT BRIEFS23AUTP10_1110/1/2023
A Guide to APU Health ManagementAIR5317A (Current)9/15/2023
AIR5317 establishes the foundation for developing a successful APU health management capability for any commercial or military operator, flying fixed wing aircraft or rotorcraft. This AIR provides guidance for demonstrating business value through improved dispatch reliability, fewer service interruptions, and lower maintenance costs and for satisfying Extended Operations (ETOPS) availability and compliance requirements.
E-32 Aerospace Propulsion Systems Health Management
A MATLAB/Simulink Model of a PEM Fuel Cell System Including Ageing Phenomenon2023-24-01488/28/2023
This paper presents a numerical model of a Polymer Electrolyte Membrane Fuel Cell (PEMFC) system reproducing an automotive-type powertrain. The 0D model is developed in MATLAB/Simulink environment, and it incorporates all the main auxiliary components (air and hydrogen supply line, cooling circuit) as well as the PEMFC stack unit. The model includes an ageing model to estimate the PEMFC stack degradation over time, resulting in progressive efficiency loss as well as in increased auxiliary power and thermal dissipation demand. The presented model enables the estimation of both PEMFC duration and of the time-varying request of heat rejection, facilitating the selection of auxiliaries to optimize the lifelong performance. The model constitutes the backbone for the design and optimization of PEMFC systems for automotive applications, and the integration with a degradation model provides a comprehensive research tool to estimate the long-term performance and lifetime of PEMFC system.
Corda, Giuseppe, Breda, Sebastiano, D'Adamo, Alessandro
ELECTRIFICATION OF MEDIUM SIZE TRACKED VEHICLE – HYDRAULIC VS ELECTRIC DESIGN AND INTEGRATION2024-01-40208/10/2023
ABSTRACT For medium sized combat vehicles, the traditional method for auxiliary power is hydraulics, based on proven track record of reliability, high output forces and excellent power density. With the transition to vehicle electrification, emphasis has been placed on the integration of electric motors into the overall architecture of the vehicle. Electric components generally are larger in size and weigh more for the amount of power they deliver compared to hydraulics. This paper will explore the integration of electric motors in a vehicle and the advantages and disadvantages as compared to hydraulic power.
Aardema, Jim, Laboda, Thomas
Interface Standard, Miniature Mission Store InterfaceAS5725C (Current)5/22/2023
This SAE Aerospace Standard (AS) defines implementation requirements for the electrical interface between: a Aircraft carried miniature store carriage systems and miniature stores b Aircraft parent carriage and miniature stores c Surface-based launch systems and miniature stores The interface provides a common interfacing capability for the initialization and employment of smart miniature munitions and other miniature stores from the host systems. Physical, electrical, and logical (functional) aspects of the interface are addressed.
AS-1B Aircraft Store Integration Committee
APU Gas Turbine Engine Test Cell CorrelationARP5435A (Current)5/19/2023
This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of APU (auxiliary power unit) 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. The baseline performance is generally determined at the original equipment manufacturer (OEM) designated test facility. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs 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
Aerospace Military Aircraft Hydraulic System CharacteristicsAIR1899A (Current)4/26/2023
This SAE Aerospace Information Report (AIR) has been compiled to provide information on hydraulic systems fitted to the following categories of military vehicles. Attack Airplanes Fighter Airplanes Bombers Anti-Sub, Fixed Wing Airplanes Transport Airplanes Helicopters Boats
A-6A2 Military Aircraft Committee
Analysis of Geo-Location Data to Determine Combat Vehicle Idling Times2023-01-01014/11/2023
As the United States Army strives for electrification and hybridization of tactical and combat vehicles in alignment with its Climate Strategy, it is necessary to capture all aspects of the drive cycle. One key area for consideration is the amount of time that the vehicles spend idling. Indeed, military vehicles can idle for a considerable amount of time, especially given that soldiers must keep their vehicles running to power critical electronic subsystems. Current, standardized drive cycles do not fully capture the degree that military vehicles idle. This study begins to address this gap by analyzing geo-location data collected from the National Training Center (NTC) for several different tactical vehicles including the High Mobility Multipurpose Wheeled Vehicle (HMMWV), the Bradley Fighting Vehicle, and the Abrams Main Battle Tank. This paper details the extraction, cleaning, and analysis of the geo-location data. The analysis provides insight to how often each vehicle type was stationary over the course of a multi-week training exercise. When coupled with common tactics required in this operating environment, the total amount of time that each vehicle was idling may be approximated. The analysis found that over a given training rotation at NTC, the vehicles spent a considerable amount of time idling, leading to a significant amount of fuel consumption. The paper concludes by evaluating opportunities to mitigate vehicle idle fuel consumption including anti-idle kits and auxiliary power units.
Mittal, Vikram, Lawrence, Brandon, Rodriguez, Andrew, Evangelista, Paul, Novoselich, Brian
Synthetic Jet Fuels from Non-Petroleum Feed StocksAIR6148 (Current)2/20/2023
This SAE Aerospace Information Report (AIR) provides general information on the developing subject of synthetic jet fuels derived from non-petroleum feed stocks. It addresses synthetic jet fuel properties and other topics associated with their use and is intended as a guide to assist aviation fuel system designers in considering important information on fuel properties when designing aircraft fuel systems and components. The AIR is limited to “drop-in” fuels that meet the requirements of the respective fuel specifications and are compatible with typical aircraft and ground refueling systems. While some key properties are included in this AIR for discussion, the reader should utilize documents such as MIL-HDBK-510 or the ASTM International research reports for a more-detailed review of fuel properties. AIR7484 also gives more details on fuel properties, specifically as they relate to airframe fuel system design.
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Wiring Aerospace VehicleAS50881H (Current)1/13/2023
This specification covers all aspects in Electrical Wiring Interconnection Systems (EWIS) from the selection through installation of wiring and wiring devices and optical cabling and termination devices used in aerospace vehicles. Aerospace vehicles include manned and unmanned airplanes, helicopters, lighter-than-air vehicles, missiles, and external pods.
AE-8A Elec Wiring and Fiber Optic Interconnect Sys Install
Design Guidelines for Aircraft Mechanical Control Systems and ComponentsARP5770A (Current)11/22/2022
This SAE Aerospace Recommended Practice (ARP) provides design guidelines for aircraft mechanical control systems and components. Topics contained in this document include design requirements, system design and installation guidelines, and component design practices for primary flight controls, secondary flight controls, and utility controls.
A-6A3 Flight Control and Vehicle Management Systems Cmt
Energy and Fuel Consumption Minimization for a Plug-In Fuel Cell Electric Cargo Handling Vehicle2022-24-00109/16/2022
The port-logistic sector has a crucial role in goods transport, as the 85-90% of international trade is achieved by means of maritime routes. The latest reports from the International Maritime Organization show that the port-logistic related activities are an important source of air pollution, both for the use of large auxiliary power systems on ships, which operate during port stays, as well as for the employment of fossil fueled road vehicles for on-site operations. As a matter of fact, the most important maritime facilities are located nearby urban areas and therefore reduction of the environmental impact in ports becomes of primary importance. Thus, in the pursuit of a greener in-port mobility, a progressive replacement of fossil fuels with cleaner alternatives must be promoted. This paper presents the analysis of the performance of a hydrogenfueled plug-in fuel cell/battery hybrid vehicle for cargo-handling in roll-on and roll-off port operations. The powertrain of the proposed vehicle has been designed by the authors in a previous work, based on experimental data acquired during in-port operations for the fossil fuel powered counterpart. An optimized energy management strategy, based on the application of the Pontryagin’s Minimum Principle, is used to assess the maximum energy and hydrogen savings that can be attained with such a powertrain. Results are obtained over different mission profiles, in terms of driving and duty cycles, in order to represent typical port operations and ensure the accomplishment of the defined target missions. Outputs from this study set the basis for the design of an optimization-based real time energy management strategy, to maximize the potential of such vehicles in the view of the replacement of the conventional vehicles for in-port operations.
Lombardi, Simone, Tribioli, Laura, Di Ilio, Giovanni, Di Giorgio, Paolo, Jannelli, Elio
Output Performance Characteristics of Auxiliary Power Units with Single-Cylinder Diesel Engines by Replacing the Magnetic Material of Generator Rotor2022-01-50679/9/2022
This is a comparative experimental study on the power generation output characteristics of auxiliary power units (APUs), with different permanent magnet materials, for trucks and special vehicles applications. The efficiency of the generator, rotor speed, torque, changes in power generation output, current, and voltage were compared and analyzed with different permanent magnet materials on the rotor. The permanent magnets composed of NdFe38 and Sm2Co17 were assembled on the generator rotor (flywheel), and their output performance characteristics were compared. The experimental results showed that efficiency is slightly higher when Sm2Co17 was installed. Moreover, when power is generated at the operating condition of the APU system, comparative tests for the rotational speed of the flywheel-mounted rotor showed that the speed of the NdFe38 permanent-magnet rotor was lower by 400 rpm. The application of NdFe38 can reduce the speed of the APU system, fuel consumption (by 5%), and noise level; this result is expected to be useful for design margins on the power generation output of vehicles in the future.
Lee, Tae Eui, Stabel, Andreas, Lee, Herry, Lee, Ga Young
A Layered Active Balance System for Lithium-ion Power Battery Based on Auxiliary Power2022-01-11328/30/2022
In this paper, a high-efficiency and low-cost lithium-ion battery pack active balance system is designed. It adopts a distributed structure and consists of three parts: auxiliary power module, one-way isolated DC/DC conversion module, and a battery group. The battery single cells in the battery pack are layered and divided into m battery groups in total, and each battery group is composed of n battery single cells. Each battery group is connected to an isolated DC/DC conversion module, and all the conversion modules are connected in parallel with the auxiliary power. Taking the SOC average value of the all-single cells in one battery group as the balancing variable, the auxiliary power is controlled to charge the battery group with the lower SOC average value, so that the difference of the SOC average value of all battery groups is within the set threshold range, so as to realize the active balance of each battery group. For the single cells in the same battery group, by controlling the closing and opening of the bypass switch, the charging and resting of each single cell is realized, and finally the balance of the SOC of the single cells in the same group is realized. This design adopts a layered and modular active balance topology, which is beneficial to improve the stability of the balance system and simplify the system structure. Multi-channel charging through the auxiliary power can balance multiple battery groups at the same time, reducing the loss of energy transmission and speeding up the active balance speed. Compared with the existing active balance topology, this design improves both economy and balance efficiency.
Fan, Longyu, Liu, Yuxi, Gao, Xinwen, Yan, Ronbin, Zhu, Haotian
NMP–free Lithium Ion for Sustainable Manufacturing in Silent-Watch Applications2024-01-39468/10/2022
ABSTRACT PPG formulates N-methyl pyrrolidone free (NMP−free) cathodes for Li−ion batteries capable of delivering sufficient power for automotive starting, lighting and ignition (SLI) as well as adequate charge capacity for powering auxiliary electronics. In this paper, NMP−free energy cathodes and power cathodes were formulated using developmental binders, and refinement of carbon/binder ratio and slurry mix procedure. Learnings from the energy and power cathode development were conceptually combined in the formulation of capacity enhanced power cathodes. These cathodes were evaluated electrochemically via power capability and rate capability testing in battery coin cells, as well as in 0.5 Ah multilayer pouch cells. Carbon content was found to be a critical factor in attaining high cold crank performance. This work represents significant steps toward potential commercialization of NMP−free cathode coated foil for Li−ion batteries. Citation: S. Esarey, A. Kizzie, C. Woodley, I. Matts, S. Hellring, Z. Zhou, G. Terrago “NMP−free Lithium Ion for Sustainable Manufacturing in Silent-Watch Applications,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022.
Esarey, Samuel L., Kizzie, Austin, Woodley, Christopher, Matts, Ian, Hellring, Stuart, Zhou, Zhilian, Terrago, Gina
Helicopter Engine/Airframe Interface Document and ChecklistARP1507B (Current)6/27/2022
This SAE Aerospace Recommended Practice (ARP) provides a guide for the preparation of a helicopter engine/airframe interface document and checklist. This document and checklist should identify the information needed by the engine manufacturer and the aircraft manufacturer to integrate the engine design with the aircraft design and either provide this information or give reference to where this information is located. The intent is to assure that the engine manufacturer and the airframe manufacturer identify and make provision for this information so it can be easily accessible to either manufacturer as needed in the development stages of an engine-airframe integration project. A related document, SAE Aerospace Information Report AIR6181, provides guidance on creating an interface control document (ICD) which addresses a subset of the aircraft-engine interface information concerning the physical and functional interfaces of the electronic engine control system (EECS) with the aircraft systems. This would include signal interfaces, digital data busses and integrated functionality with the aircraft electronic systems and avionics displays. The engine/airframe interface document should reference this EECS ICD rather than duplicate its information. Similarly, as information is documented in the engine installation manual or engine installation drawings, the engine/airframe interface document should make references to the engine installation manual or engine installation drawings, rather than duplicate the information. Typically, the engine/airframe interface document will be the initial document in the project to capture the interface information which can then transition to referenced information as the engine installation manual, EECS ICD, and engine installation drawings are developed.
S-12 Powered Lift Propulsion Committee
Primary Single Phase Nominal 120 VAC Wiring Distribution Assembly Design—Truck and BusJ2698_202206 (Current)6/22/2022
This SAE Recommended Practice covers the design and application of primary on-board wiring distribution system harnessing for surface vehicles. This document is intended for single phase nominal 120 VAC circuits that provide power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off. The power supply comes from alternative sources such as land-based grid power, DC-AC inverters and auxiliary power generators. The circuits may also provide power to improve vehicle performance through charging batteries or operating cold-weather starting aids.
Truck and Bus Electrical Systems Committee
How to Get Work from a Variable-Inertia Flywheel2022-01-06403/29/2022
Suppose we have two identical variable-inertia flywheels and we connect them to the inputs of a differential. The output is connected to the driveline of a vehicle. There are several types of three-element mechanical differentials (e.g. ring-gear/carrier, epicyclic, etc.). The specific type of 3-element mechanical differential is inconsequential in the following analysis except to say there are two inputs (e.g. side gears) and one output (e.g. carrier/ring-gear). What’s important is simply the relationship - For example, using the notation ‘a’ for the first side gear and ‘b’ for the second side gear and ‘c’ for the carrier, then the relationship is: c=(a+b)/2. Understand that ‘a’, ‘b’, and ‘c’ can each be an input or an output. Using the designation ‘omega’ (ω) then the relationship looks like this: ωc=(ωa+ωb)/2. So, we have one variable inertia flywheel (VIFa) and a second variable inertia flywheel (VIFb) connected to two side gears, a and b, and a vehicle driveline connected to the differential carrier, c. For starters, we set the inertia of VIFa to its maximum inertia value, Iamx, and the inertia for VIFb to its minimum inertia value, Ibmn. Then we will spin up (with some auxiliary power source) VIFa to a minimum initial velocity (ωamn) and, in a reverse direction, VIFb to its maximum velocity (ωbmx). At this point, the ‘output’ to the vehicle driveline will be (ωamn-ωbmx)/2. But, at these initial conditions we need for the driveline angular velocity to equal zero. This can only be done by incorporating speed-changing gear set between the flywheels and the differential inputs. This gear set can change the speed of either VIFa or VIFb or both. Let’s apply the ratio (r=ωamn/ωbmx) equally to each differential input. Let’s put some numeric values to this system: ωamn=10; ωbmx=-30. If we want equal speed change for both flywheels as a percentage (i.e. equal ratio of change) then we can find the ratio (r) by taking the root: r=sqrt(ωbmx/ωamn)=1.732. Thus, the initial velocity of each VIF at the input to the differential is: ωadif=r*ωamn=17.32 while ωbdif=ωbmx/r=-17.32. What we have accomplished with these two gear sets applied to the differential inputs is that at the initial velocities for each VIF, the output of the differential is zero. The point of this is that when the vehicle is at a standstill, if we change the inertia setting of each flywheel, decreasing the inertia of VIFa (its inertia was initially at its maximum) while simultaneously increasing the inertia of VIFb (its initial inertia was set to its minimum value) we will cause the angular velocity of VIFa to increase (conserving momentum) while the negative angular velocity of VIFb will decrease (conserving momentum) and ,since VIFb is rotating in a reverse direction of VIFa, the torque produced by each flywheel as they change velocity will be in the same direction and applied to the differential output thus accelerating the vehicle.
Gramling, James
High-Fidelity Heavy-Duty Vehicle Modeling Using Sparse Telematics Data2022-01-05273/29/2022
Heavy-duty commercial vehicles consume a significant amount of energy due to their large size and mass, directly leading to vehicle operators prioritizing energy efficiency to reduce operational costs and comply with environmental regulations. One tool that can be used for the evaluation of energy efficiency in heavy-duty vehicles is the evaluation of energy efficiency using vehicle modeling and simulation. Simulation provides a path for energy efficiency improvement by allowing rapid experimentation of different vehicle characteristics on fuel consumption without the need for costly physical prototyping. The research presented in this paper focuses on using real-world, sparsely sampled telematics data from a large fleet of heavy-duty vehicles to create high-fidelity models for simulation. Samples in the telematics dataset are collected sporadically, resulting in sparse data with an infrequent and irregular sampling rate. Captured in the dataset was geospatial information, time series measurements, and vehicle-specific metadata from a subset of 96 vehicles from varied geographic regions across North America. A series of custom algorithms was developed to process vehicle data and derive both vehicle model input parameters and representative drive cycles. Derived models provide a basis on which to simulate real-world vehicles and iterate on vehicle aerodynamics, auxiliary power loads, transmission shift schedules, and other parameters to achieve reduced fuel consumption and increase energy efficiency. Notably, these models were developed without the use of expensive field data collection, using only data collected through fleet telematics. Processed representative drive cycles are used to validate the fuel economy of derived models. The models developed through this research allow for more representative vehicle simulations with increased flexibility regarding vehicle-to-vehicle variations.
Carow, Kyle, Cantwell, Nathaniel, Ivanco, Andrej, Holden, Jacob, Baker, Chad, Miller, Eric, Asher, Zachary
Modeling Climate Control Loads and the Impact on Vehicle Range for Last-Mile Electric Delivery Trucks in Cold Climates2022-01-01993/29/2022
In cold climates, cells in the high voltage battery of an electric vehicle are subject to environment-related performance degradation leading to a decrease in effective range. Active battery temperature regulation is often implemented in battery electric vehicles (BEVs) to mitigate the detrimental effects of extreme ambient temperatures on battery state of health and effective nominal capacity. However, low ambient temperature also impacts driver comfort leading to added auxiliary power demands to regulate the cabin temperature. This work focuses on evaluating the increased auxiliary power demand from vehicle heating, ventilation, and air condition (HVAC) systems in cold climates. Practical driving data was periodically collected from an instrumented medium-duty delivery vehicle over several cold winter months in Minnesota, USA. A simplified empirical model to estimate HVAC power requirements was developed from relevant temperature and air speed measurements within the vehicle. Using a physically-similar BEV model for simulations, the effects of driving in a range of cold ambient temperatures on the energy usage and effective vehicle range were assessed. The results show that reasonably accurate auxiliary power estimates (below 6% mean absolute percentage error) can be achieved through the proposed data-driven modeling approach. The developed methodology can aid future researchers in isolating the effects of ambient temperatures on battery performance degradation in cold ambient conditions.
Eagon, Matthew, Trujillo, Jeromy, Northrop, William
Transient Measurement Method Development for Aircraft Propulsion Engine and Auxiliary Power Unit Generated Contaminants in Bleed AirAIR6418 (Current)3/29/2022
This SAE Aerospace Information Report (AIR) outlines transient measurement methods to determine engine-generated levels of relevant compressor bleed air contaminant marker compounds on a ground level test cell for aircraft propulsion engine or auxiliary power unit (APU) to be fitted on civil and military aircraft. This AIR focuses on lubrication oils that might enter the bleed air through leaking engine seals or other sources. Also considered are ingested engine combustion products, which must be differentiated from oil. The intent of this AIR is to identify key species that are markers typical of contaminants, not to characterize all possible contaminants. Real-time (transient) measurement methods to approximately quantify those markers are also discussed. Real-time methods developed for transient measurement could also be applied for real-time measurements in steady state operations in ground level test beds. Discussions of test setup and test procedures, techniques for sampling ambient air and compressor bleed air, and one or more specific analytical methodologies for each of the identified bleed air contaminant marker compounds are included. This AIR will not recommend levels of acceptability.
E-31B Bleed Air Committee
Testing of Airplane Installed Environmental Control Systems (ECS)ARP217D (Current)12/27/2021
This document deals with ground and flight test of airplane installed Environmental Control Systems (ECS), Figure 1. The ECS provide an environment, controlled within specified operational limits of comfort and safety, for humans, animals, and equipment. These limits include the following: pressure, temperature, humidity, ventilation air velocity, ventilation rate, wall temperature, audible noise, vibration, and environment composition (ozone, contaminants, etc.). The ECS are composed of equipment, controls, and indicators that supply, distribute, recycle and exhaust air to maintain the desired environment.
AC-9 Aircraft Environmental Systems Committee
Multi-Pass Method for Evaluating Filtration Performance of Fine Lube Filter Elements Utilized in Aerospace Power and Propulsion Lubrication SystemsARP5454C (Current)12/21/2021
This SAE Aerospace Recommended Practice (ARP) describes the multi-pass method for evaluating the filtration performance of fine lube filter elements, commonly utilized in aerospace power and propulsion lubrication systems: gas turbine engines, auxiliary power units (APUs), helicopter transmissions, constant speed drives (CSDs), and integrated drive generators (IDGs).
AE-5B Aircraft and Engine Fuel and Lubricant Sys Components
Compartment Decompression AnalysisAIR5661A (Current)12/17/2021
This SAE Aerospace Information Report (AIR) provides data and general analysis methods for calculation of internal and external, pressurized and unpressurized airplane compartment pressures during rapid discharge of cabin pressure. References to the applicable current FAA and EASA rules and advisory material are provided. While rules and interpretations can be expected to evolve, numerous airplanes have been approved under current and past rules that will have a continuing need for analysis of production and field modifications, alterations and repairs. The data and basic principles provided by this report are adaptable to any compartment decompression analysis requirement.
AC-9 Aircraft Environmental Systems Committee
Heat Sinks for Airborne VehiclesAIR1957A (Current)12/15/2021
This document summarizes types of heat sinks and considerations in relation to the general requirements of aircraft heat sources, and it provides information to achieve efficient utilization and management of these heat sinks. In this document, a heat sink is defined as a body or substance used for removal of the heat generated by thermodynamic processes. This document provides general data about airborne heat sources, heat sinks, and modes of heat transfer. The document also discusses approaches to control the use of heat sinks and techniques for analysis and verification of heat sink management. The heat sinks are for aircraft operating at subsonic and supersonic speeds.
AC-9 Aircraft Environmental Systems Committee
Products of Tomorrow: October 2021TBMG-3996510/1/2021
This column presents technologies that have applications in commercial areas, possibly creating the products of tomorrow. To learn more about each technology, see the contact information provided for that innovation.
Intelligent Auxiliary Battery Control - A Connected Approach2021-01-12489/21/2021
As vehicles are getting electrified and more intelligent, the energy consumption of the auxiliary system increases rapidly. The auxiliary battery acts as the backbone of the system to support the proper operation of the vehicle. It is important to ensure the auxiliary battery has enough energy to meet the basic loads regardless the vehicle is in park or running. However, the existing methods only focus on auxiliary energy management when the vehicle is in a dynamic event. To fulfill the gap, we propose an intelligent strategy that detects the low state of charge (SOC) condition, temporarily turns down the auxiliary loads based on their priorities and charges the auxiliary battery at the maximum efficiency of the auxiliary power unit. In addition, the proposed strategy allows the vehicle to get the park duration update and make intelligent decisions on charging the auxiliary battery. Simulation results indicate that our strategy closes the technology gap that is not addressed by the existing methods. As a result, the energy consumption remains low while the SOC of the auxiliary battery is sustained.
Kumar, Vivek, Zhu, Di, Dadam, Sumanth Reddy
Fluorescent Penetrant Inspection Aircraft Structures and Engine Component MaintenanceAMS2647G (Current)9/20/2021
This specification details requirements and procedures for the detection of defects in aircraft structural and engine components during maintenance and overhaul operations.
AMS K Non Destructive Methods and Processes Committee
Assessment of a Hydrogen-Fueled Heavy-Duty Yard Truck for Roll-On and Roll-Off Port Operations2021-24-01099/5/2021
The port-logistic industry has a significant impact on the urban environment nearby ports and on the surrounding coastal areas. This is due to the use of large auxiliary power systems on ships operating during port stays, as well as to the employment of a number of fossil fuel powered road vehicles required for port operations. The environmental impact related to the use of these vehicles is twofold: on one hand, they contribute directly to port emissions by fuel consumption; on the other hand, they require some of the ship auxiliary systems to operate intensively, such as the ventilation system, which must operate to remove the pollutants produced by the vehicle engines inside the ship. The pathway to achieve decarbonization and mitigation of energy use in ports involves therefore the adoption of alternative and cleaner technology solutions for the propulsion systems of such port vehicles. This paper presents the performance analysis of a hydrogen powered cargo-handling vehicle for roll-on and roll-off port operations in a real case scenario. The fuel cell/battery hybrid powertrain of the vehicle has been previously designed by the authors. On the base of real data acquired during an on-field measurement campaign, and by means of a validated numerical model of the vehicle dynamics, different mission profiles are defined, in terms of driving and duty cycles, in order to represent typical port operations. A rule-based energy management strategy is then used to estimate the energy and hydrogen consumptions required by the vehicle and to assess its suitability to accomplish the defined target port operations. Outputs from this study show the potential of the proposed solution to take the place, in a foreseeable future, of conventional Diesel-engine vehicles, today commonly used in port logistics, towards a zero-emission scenario.
Di Ilio, Giovanni, Di Giorgio, Paolo, Tribioli, Laura, Cigolotti, Viviana, Bella, Gino, Jannelli, Elio
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