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SCOPE IS UNAVAILABLE.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
SCOPE IS UNAVAILABLE.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
The clearance between the impeller and pump head is a critical parameter of the hydrogen recirculation pump used in proton exchange membrane fuel cell (PEMFC) systems, and it significantly affects performance, efficiency, and reliability. This study investigates the impact of clearance on the performance of a hydrogen recirculation pump applied in PEMFC systems. Both numerical simulation and experimental methods are employed to systematically evaluate the effects of symmetric circular clearances ranging from 0 to 0.4 mm, as well as asymmetric clearance configurations representative of manufacturing tolerances and assembly deviations. According to the research results, the pressure rise increases with the clearance decreasing under a given flow rate, and a smaller clearance would show a stronger capability to cover a larger flow rate range. The clearance impact on the performance of the hydrogen recirculation pump is found to be in the lower flow rate zone. In addition, the pressure
Xie, LuZhong, HaoTsoi, Jeffrey
The present review evaluates recent advances in the development of Welding-Based Additive Manufacturing (WBAM) technologies using arc, high-energy density, solid-state, and hybrid welding systems by providing an interdisciplinary assessment of technological aspects, sensing, process optimization, and multi-process strategies. It is concluded that, in spite of considerable progress in process optimization and control, there exist numerous paradoxes associated with relationships among process conditions, structure, and properties, especially those related to heat input effects on material microstructure and performance. An important finding is the fragmentation of predictive modeling approaches, where physics-based and data-driven methods remain inadequately integrated, limiting generalizability and accuracy. Another important conclusion is related to the dominance of the effect of thermal history and multi-physical phenomena on the mechanical performance of the material produced by WBAM
Santhana Babu, A.V.John Rajan, A.Mishra, AishwaryChakravarthy, P.Jayabalakrishnan, D.
Knowing a detailed operating cycle is critical for developing and testing equipment. Operating cycles can be separated by two clear distinctions: (1) regulatory or non-regulatory and (2) application at the engine-only or full machine level. The Environmental Protection Agency’s (EPA) Nonroad Transient Cycle (NRTC) may be a good representation of engine use in many types of equipment, but there is a gap in standardized and validated drive cycles specifically for nonroad material handlers. Lacking a standardized drive cycle makes it difficult to accurately benchmark machine performance and validate new powertrain technologies. The objective of this investigation is to illustrate the development of a custom drive cycle augmented with real-world customer use data that serves multiple purposes: (1) understand the range of operation and utilization that formulated inputs for electrified architecture analysis and (2) develop a repetitive and consistent maneuver to establish baseline energy
Czarnecki, AlexanderGoodenough, BryantWorm, JeremyRobinette, DarrellLaTendresse, PhilWestman, John
Individuals who complete the applicable modules aligned with this training document will be able to define the type of damage, define the extent of damage, determine if further inspection is required, evaluate the damage against published allowable damage limits, and provide accurate documentation of the damage. The intended outcome of the training is increased safety such that no aircraft is released with unknown damage and that the aircraft meets continued airworthiness requirements. The goal is to change the culture from damage discovery to damage reporting while also reducing or eliminating flight delays due to incorrect or insufficient information. Teaching levels have been assigned to the curriculum to define the knowledge, skills, and abilities graduates will need. Minimum hours of instruction have been provided to ensure adequate coverage of all subject matter including lecture and practical exercise. These minimums may be exceeded and may include an increase in the total
AMS CACRC Commercial Aircraft Composite Repair Committee
AMS6885/2 gives specific information about the qualification program for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The prepreg system shall include an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS CACRC Commercial Aircraft Composite Repair Committee
With the recent renewed interest in manned lunar exploration, it is critical to revisit the Apollo Moon landings with new analysis tools. Modeling the Moon landings of the past can help guide the development of new landing vehicles for the present and the future. One of the critical subsystems to model is the vehicle’s landing gear. During a landing event, structural loading, energy absorption, and toppling stability are important factors that drive the design of landing gear subsystems. These aspects can be studied using models and simulations in addition to physical testing. This study explores one recent modeling tool for modeling the landing gear and uses the Apollo 11 Moon landing as a use case. A generic model was built using MATLAB®, Simulink®, and Simscape® Multibody to model the dynamics of a landing event. The landing gear structure comprising the primary strut, secondary struts, footpads, and joints was modeled in Simscape® Multibody. Various energy absorption mechanisms in
Arndt, GrantWu, WeiButzman, Noah
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Agricultural vehicles operating in rough environments experience increased fatigue damage accumulation, which may decrease machine safety and reliability. Autonomous agricultural machines offer an opportunity to incorporate fatigue damage considerations into path planning. This work investigates whether machine learning can predict fatigue damage to a tractor chassis using light detection and ranging (LiDAR)-based terrain features, vehicle speed, and rotational vehicle state data (e.g., triaxial angle, angular velocity, and angular acceleration). Fatigue damage was estimated using the Rupp filter and the Durability Transfer Concept. Following poor predictive performance of the machine learning models, an exploratory analysis of damage histograms, dominant frequency, and acceleration magnitude was performed. Results indicated that most estimated fatigue damage occurred in the 0–2 Hz band, which coincides with the frequency range of terrain-induced acceleration. On-road driving led to
Govers, Megan EmilyHamilton-Wright, AndrewHassan, MarwanOliver, Michele L.
AMS6885/1 gives information about the technical requirements and qualification procedure for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The repair system includes an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS CACRC Commercial Aircraft Composite Repair Committee
Alloy wheels are essential safety components in two-wheeled vehicles. This study details the finite element analysis (FEA) used to simulate and evaluate the wheel and tire performance under the double mass impact load specified by the AIS-073 (Part-1) standard. The impact is carried out by dropping a striking mass along with a main mass onto the alloy wheel–tire assembly, as per the standard. The alloy wheel is modeled using a three-dimensional finite element model with elastic-plastic material behavior, and the tire is modeled with its internal elements (e.g., carcass, belt, etc.). The prediction of wheel impact failure is based on the total plastic work of the ductile fracture mechanism. The validity of results is confirmed by comparing the predicted permanent lateral rim deformation against the measured lateral deformation from a corresponding physical test.
Minz, Jai ShankarSingh, Sanjay KumarNirala, Deepak Kumar
This document (Technical Specification) gives information about qualification rules and the relation between the different specification parts involved, such as the Technical Specification (TS), the Material Specification (MS), and the Purchasing Specifications (PS).
AMS CACRC Commercial Aircraft Composite Repair Committee
Ethanol requires elevated intake temperatures to initiate autoignition in Homogeneous Charge Compression Ignition (HCCI) as a high-octane single-stage fuel. To leverage the high thermal efficiency, low engine-out NOx, and near-zero soot inherent to HCCI with ethanol, a custom piston design was developed to enable high compression ratios (CR) up to 22.5:1. This study investigates HCCI combustion with ethanol at three CRs of 17.5, 20.0, and 22.5 through equivalence ratio and boost sweeps performed to assess the reduction in the intake temperature requirement at high CRs and the emissions and efficiency trade-offs. Results indicate a clear benefit with reduced intake temperature requirements with increasing CR. However, a combustion efficiency penalty was observed at high CRs. Three-dimensional Computational Fluid Dynamics (CFD) simulations were performed using Large Eddy Simulation (LES) coupled with a detailed chemistry model to investigate the underlying mechanisms of the combustion
Vedpathak, KunalKumar, MohitMotwani, RahulDatar, AdityaGainey, BrianLawler, Benjamin
This AIR provides a general guideline on how to perform effective measurement systems analysis study (MSA) for rotor balancing tasks. The document also includes applicable data analysis methods and result interpretation.
EG-1A Balancing Committee
This test method outlines the standard procedure for measuring the radial and axial internal clearance of rolling element bearings used in airframe controls.
ACBG Rolling Element Bearing Committee
This SAE Aerospace Information Report (AIR) provides descriptions of test methods for determining if an aircraft surface coating of any thickness has adverse effects on aircraft deicing/anti-icing fluids with respect to fluid holdover time performance and aerodynamic performance. Although not the primary mandate of the G-12 Aircraft Ground Deicing Committee, this document also provides descriptions of suggested test methods for evaluating aircraft surface coatings with respect to durability, hardness, weathering, aerodynamic drag, ice adhesion, ice accumulation, contact angle, and thermal conductivity. These additional tests can provide informational data for characterizing the coatings and may be useful to operators when evaluating the coatings.
G-12ADF Aircraft Deicing Fluids
This document describes the major design drivers and considerations when designing a fuel system for a large commercial aircraft. While not intended as a design manual for individual system components, it does refer out to other SAE specifications where more detail on specific components and subsystems is given. It does include examples of a number of calculations associated with sizing of fuel systems, based on those given in NAVAIR 06-5-504, as well as an appendix summarizing basic fluid mechanical equations that are key for fuel system design. It is acknowledged that most of these calculations would today be performed by modeling tools rather than by hand, but it is considered important for the designer to understand the principles. Some details specific to military aircraft are included, but it is intended that later issues of this document will include appendices that give specific considerations for military aircraft, smaller commercial aircraft, and rotorcraft. Features unique
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Regulators and policymakers have introduced increasingly stringent limits on tailpipe CO₂ and pollutant emissions to accelerate the decarbonization of heavy-duty vehicle applications. The development of innovative propulsion technologies — such as advanced combustion systems, low-friction reciprocating components, and improved aftertreatment solutions — combined with hybridization and the adoption of alternative fuels (e.g., biogas, HVO, green hydrogen), is a key pathway for meeting future emission and GHG targets. In this study, advanced combustion systems were developed for a 13-liter diesel engine for heavy-duty truck applications, with the objective of meeting forthcoming Euro VII regulations while maximizing thermal efficiency. The combustion system architecture—including open-bowl geometry with high aspect ratio, injector nozzle with wider spray opening angle, and reduced swirl ratio—was optimized using a Machine Learning–algorithm trained on high-fidelity 3D CFD combustion data
Belgiorno, GiacomoCentini, Maria PiaPezza, VincenzoCozza, Ivan F.Pesce, Francesco C.Vassallo, AlbertoColombo, GiovanniGallo, AlessandroMirzaeian, MohsenBorg, Jonathan
As vehicle technologies evolve toward electrification and advanced aftertreatment, understanding the biological implications of their exhaust emissions remains essential. This study presents a harmonized comparative toxicological assessment of five Euro 6 vehicles representing gasoline, hybrid, plug-in hybrid, compressed natural gas (CNG), and diesel technologies. Vehicles were tested under realistic driving conditions on a chassis dynamometer. Diluted exhaust was delivered directly to human lung epithelial cells (A549) using a controlled air–liquid interface (ALI) exposure system. Solid and total particle number emissions were measured, and deposited particle mass was estimated from size-resolved distributions and deposition efficiency. Vehicles equipped with particulate filtration showed lower solid particle emissions overall, while differences between gasoline particulate filter-equipped vehicles indicated that hybridization can further influence emission levels. Diesel operation
Tsakonas, GeorgiosStamatiou, RodopiLazou, AntigoneSamaras, ZissisElihn, Karine
Besides the electrification of the transport sector, the growing interest in alternative fuels for internal combustion engines represents a promising pathway to effectively decarbonize transportation over the coming decades. Predictive combustion models implemented within CFD frameworks are a critical tool to guide the design of next-generation internal combustion engines fuelled with alternative fuels. Accurate prediction of the combustion heat release process is influenced by multiple interacting parameters, requiring combustion models that can reliably adapt to variations in fuel chemical properties and operating conditions. In this study, two well-established combustion models considered to model combustion development in Spark-Ignition engine, namely the Extended Coherent Flame Model (ECFM) and the G-equation model, are compared to assess their capability to adapt to changes in fuel chemical composition. Both models, based on the flamelet formulation are deliberately tested beyond
Sola, RiccardoBaratta, MirkoMisul, DanielaRousselle, ChristineBREQUIGNY, PierreColin, Olivier