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Liquefied petroleum gas (LPG) is a popular alternative fuel in the transportation sector as a result of its favorable physical and chemical properties, availability, and relatively lower emissions compared to conventional fuels. However, much of its use is currently in light-duty applications, usually in manifold or port-injected configurations primarily due to their simplicity and ease of conversion. However, there are shortfalls in heavy-duty applications where decarbonization efforts are direly needed. The key reasons for this shortfall in alternative fuel adoption in the heavy-duty sector are the deficit in engine performance when compared to conventional heavy-duty diesel engines and the lack of specialized hardware to bridge this performance gap, for example, direct injectors optimized for LPG fuel operation on large-bore engines. To address this, this study evaluated the performance, emissions, and combustion characteristics of a heavy-duty single-cylinder research engine, the
Fosudo, ToluwalaseWindom, BretOlsen, Daniel
The purpose of this document is to provide a standard for aircraft fuselage markings located at the doors used for ground servicing operations. These markings can be used by all GSE that will dock at the aircraft. These markings may be used for one or several phases of the GSE positioning relative to the aircraft process: GSE alignment during approach, GSE final docking, and GSE auto leveling. It is not the purpose of this standard to describe the different technologies, cameras, or other equipment that can be mounted on GSE to utilize these markings. The aircraft that may use these markings will have a fuselage diameter of 3 m or more.
AGE-3 Aircraft Ground Support Equipment Committee
In electrified drivetrains, lubricants are commonly in contact with the motor and other electrical components as well as the gears and bearings. Copper, present in these electrical components, is susceptible to corrosion by fluids containing active sulfur, which can lead to catastrophic failure of the unit. Lubricating fluids for electric vehicles (referred to as e-fluids) must not cause corrosion and must maintain high performance while having suitable electrical conductivity, material compatibility, and heat transfer properties. We describe a new formulation without active sulfur that has recently entered the market, which can protect against copper corrosion. We show that this e-fluid can provide suitable wear protection under field trial conditions, and that the e-fluid provides improved wear protection in bearing (FE-8) tests compared to a traditional extreme pressure axle fluid (API GL-4). Surface analysis (X-ray photoelectron spectroscopy) measurements of the component surfaces
Hopper, Elizabeth R.Williams, Megan S.Gahagan, Michael
This SAE Aerospace Standard (AS) provides requirements for design and installation of aircraft jacking pad adapters and the mating jack socket interface to permit use of standard jacking equipment to be used in civil and military transport aircraft. The adapter defined herein shall be the key interface between the aircraft and the aircraft jack(s).
AGE-3 Aircraft Ground Support Equipment Committee
This SAE Recommended Practice is intended to establish a procedure to certify the fundamental driving skill levels of professional drivers. This certification can be used by the individual driver to qualify their skills when seeking employment or other professional activity. These certification levels may also be used by test facilities or other organizations when seeking test or professional drivers of various skills. The associated family of documents listed below establish driving skill criteria for various specific categories. SAE J3300: Driving level SAE J3300/1: Low mu/winter driving SAE J3300/2: Trailer towing SAE J3300/3: Automated driving Additional certifications to be added as appropriate. This main document provides: (1) common definitions and general guidance for using this family of documents, (2) directions for obtaining certification through Probitas Authentication®1, and (3) driving level examination requirements.
Driving Skills Standards Committee
Letter from the Guest Editors
Liang, CiTörngren, Martin
Software reliability prediction involves predicting future failure rates or expected number of failures that can happen in the operational timeline of the software. The time-domain approach of software reliability modeling has received great emphasis and there exists numerous software reliability models that aim to capture the underlying failure process by using the relationship between time and software failures. These models work well for one-step prediction of time between failures or failure count per unit time. But for forecasting the expected number of failures, no single model will be able to perform the best on all datasets. For making accurate predictions, two hybrid approaches have been developed—minimization and neural network—to give importance to only those models that are able to model the failure process with good accuracy and then combine the predictions of them to get good results in forecasting failures across all datasets. These models once trained on the dataset are
Mahdev, Akash RavishankarLal, VinayakMuralimohan, PramodReddy, HemanjaneyaMathur, Rachit
This SAE Recommended Practice defines the minimum functional requirements for quick connect couplings used for supply, return, and vapor/emission fuel system connections. This document also defines standard male tube end form dimensions, so as to guarantee interchangeability between all connector designs of the same male tube end form size. This document applies to automotive and light truck applications under the following conditions: a Gasoline and diesel fuel delivery systems or their vapor venting or evaporative emission control systems. b Operating pressure up to 500 kPa, 5 bar, (72 psig). c Operating vacuum down to −50 kPa, −0.5 bar (−7.2 psi). d Operating temperatures from −40 °C (−40 °F) to 115 °C (239 °F). Quick connect couplings function by joining the connector to a mating tube end form, then pulling back to assure a complete connection. The requirements stated in this document apply to new connectors in assembly operations unless otherwise indicated. For service operations
Fuel Systems Standards Committee
The “Model Architecture and Interfaces Recommended Practice for Ground Vehicle System and Subsystem Dynamical Simulation” defines the architectural structure of a ground vehicle system dynamical model by partitioning it into subsystem models and by defining subsystem interfaces required to enable plug-and-play operation of a dynamical simulation models. All types of ground vehicle were considered in the development of the architecture, such as, passenger cars, light and medium duty trucks, heavy duty tractor trailer trucks, and vehicles/equipment for military, farming, construction, and mining. Versatility of this architectural partitioning is demonstrated by showing how it can be applied to different vehicle configurations. Application examples of architecture are provided for a large number of the publicly known ground vehicle configurations in production, testing, or development. This recommended practice encompasses standards to enable seamless plug-and-play reusability of
Dynamical Modeling and Simulation Committee
Currently, effective methods for analyzing the aerodynamic sound sources of Sport Utility Vehicles (SUVs) are still under development, and the relationship between sound sources and flow dynamics is not yet fully understood. This study presents a method for identifying multi-frequency sound dipole sources within the near-wall flow field by analyzing the relationship between unsteady flow field properties and dipole sources, thereby addressing the complex characteristics of aerodynamic sound sources on vehicle surfaces. Wind tunnel tests, along with full-scale (1:1) Large Eddy Simulation (LES) were conducted on a real SUV. The identification method was applied to analyze the location and magnitude of sound sources near the vehicle's surface. The results, validated using Acoustic Perturbation Equations (APE), indicated that the dipole sources are primarily distributed around the windward side of the front wheels, the side of the front headlights, the A pillar-side mirror-front side
Zhang, HaoJia, QingWang, Yigang
This study focuses on the numerical analysis of weather-strip contact sealing performance with a variable cross-sectional design, addressing both static and dynamic behaviors, including the critical issue of stick-slip phenomena. By employing finite element modeling (FEM), the research simulates contact pressures and deformations under varying compression loads, DCE (Door Closing Efforts) requirements, typical in automotive applications. The analysis evaluates how changes in the cross-sectional shape of the weather-strip affect its ability to maintain a consistent sealing performance, especially under dynamic vehicle operations. The study also delves into stick-slip behavior, a known cause of noise and vibration issues, particularly improper/ loosened door-seal contact during dynamic driving condition. This study identifies key parameters influencing stick-slip events, such as friction coefficients, material stiffness, surface interactions, sliding velocity, wet/dry condition
Ganesan, KarthikeyanSeok, Sang HoSun, Hyang Sun
Platform based vehicle development is standardized at John Deere. The challenges of frontloading the integration of individual components within different platforms using predictive methods is key to shortening the development cycle. Components are individually characterized on test benches and results cannot directly be used to evaluate system performance. Invariant characterization is needed instead, which is possible through techniques such as blocked loads estimation. To evaluate the applicability of such methods, the component-based loads and vehicle in-situ operational loads need to be compared. The confident use of these methods for obtaining structural and acoustic loads enables the use of hybrid system models, enhancing early NVH response predictions. The objective of this work was to enable the confident use of test stand measurements in predictive models across various vehicle platforms. This study compares a powertrain characterization in a vehicle against a test stand to
Vesikar, Prasad BalkrishnaEdgington, JasonDrabison II, John
Noise transmission through the vehicle dash panel plays a critical role in isolating passengers from noise sources within the motor bay of the vehicle. Grommets that contain electrical harness routing as well as HVAC lines are examples of dash panel pass-throughs that should be selected with care. Acoustic performance of these components is generally characterized in terms of measured quantities such as noise reduction (NR), sound transmission loss (STL), and insertion loss (IL). These measurements need to be carried out per SAE or ASTM standards in appropriate anechoic or reverberant chambers as this is important for consistency. This work explores an in-situ measurement of the grommet STL performance in the vehicle environment. It utilizes a repurposed vehicle with its cabin retrofitted to serve as an anechoic chamber and its frunk acting as a reverberant chamber. Results of this in-situ measurement are then compared to measurements following industry standards to discuss the
Joodi, BenjaminJayakumar, VigneshChang, MichaelGeissler, ChristianPilz, FernandoConklin, Chris
Mechanical light detection and ranging (LiDAR) units utilize spinning lasers to scan surrounding areas to enable limited autonomous driving. The motors within the LiDAR modules create vibration that can propagate through the vehicle frame and become unwanted noise in the cabin of a vehicle. Decoupling the module from the body of the vehicle with highly damped elastomers can reduce the acoustic noise in the cabin and improve the driving experience. Damped elastomers work by absorbing the vibrational energy and dispelling it as low-grade heat. By creating a unique test method to model the behavior of the elastomers, a predictable pattern of the damping ratio yielded insight into the performance of the elastomer throughout the operating temperature range of the LiDAR module. The test method also provides an objective analysis of elastomer durability when exposed to extreme temperatures and loading conditions for extended periods of time. Confidence in elastomer behavior and life span was
Russell, CaseyMasterson, PeterO'Connell, Kerry
In today’s fast changing and competitive automotive world, vehicle NVH plays an important role in customer’s perception of the brand. A silent cabin with lower noise levels is a desired attribute in a modern car. In such a scenario, abnormal noises arising because of manufacturing variations and tolerances of components can impact the brand image of any automotive company negatively. This paper presents an investigation into a noise issue arising drive shaft of an automotive vehicle while driving on rough roads at low speeds. Various technical measurements, including rotational backlash and dimensional assessments, were conducted, all of which were found within specification. However, axial play between the tripod and the mid-shaft spline was identified during disassembly. Further analysis revealed that material localization was the only change point in the drive shaft manufacturing process. The fit interference between the tripod spline and the mid-shaft spline was lower due to lower
Dhankhar, Dinesh SinghMishra, AshishKirti, ViplavRana, DeepakBhardwaj, AshishSingh, Karanveer
Reducing gear rattle noise within the passenger cabin is a crucial objective in vehicle development due to its direct impact on customer comfort and driving experience. Gear rattle occurs when free gears collide during meshing, primarily driven by high torsional vibrations generated by engine fluctuations. These vibrations are transmitted through the clutch system to the transmission, amplifying noise inside the cabin. This study focuses on optimizing the clutch by stabilizing its hysteresis to address this issue. This helps minimize the torsional vibrations transferred to the transmission input shaft, thereby reducing gear rattle. The investigation centers on a case where significant gear rattle was observed at high vehicle speeds, particularly under high engine torque conditions. A thorough root cause analysis identified that the primary contributor to the noise was a drop in the clutch hysteresis value at elevated engine torques. This drop increased torsional vibrations in the
Awasthi, MradulDhankhar, Dinesh SinghKhare, Devendra KumarRana, DeepakPandey, Anant
In the development of engine mounting systems for passenger cars, accurately capturing dynamic loads during real-world driving conditions is crucial for optimizing performance, durability, and NVH (Noise, Vibration, and Harshness) characteristics. This paper introduces an innovative approach that integrates load cell and strain gauge technologies for Road Load Data (RLD) acquisition, specifically designed for engine mounting applications. By combining load cells and strain gauges, this method offers a comprehensive solution for measuring both direct forces and the resulting strains on engine mounts, providing a more detailed understanding of the load profiles. Load cells capture the overall forces exerted on the engine mounts, while strategically placed strain gauges measure local deformations and stress distributions within the mounts. This dual-method approach enables precise correlation of force and strain data, enhancing the accuracy of load calculations under various driving
Hazra, SandipKhan, Arkadip AmitavaMohare, Gourishkumar
Electric drive units (EDU) of battery electric vehicles and electric drivetrain components of hybrid vehicles require significant development effort and planning to ensure that a refined NVH sound quality is achieved. New tools and methods are required to understand the NVH performance throughout the development process and to ensure that NVH risks can be quickly identified and mitigated within the correct EDU subsystems. This paper discusses the development of a methodology (EDSL – Electric Drive Sound Level) aimed at addressing this need. It also outlines how the EDSL process can be used to address radiated noise issues and understand the NVH performance of the various subsystems within an electrified drivetrain component. The first use of the EDSL methodology is to characterize component-level radiated noise test results and compare the different mechanical and electrical noise sources to targets. The results from this are used to guide EDU development in the appropriate areas
Pruetz, Jeffrey E.Steffens, ChristophFu, TongfangFord, Alex
The Sottek Hearing Model provides a comprehensive framework for understanding the nuances of sound perception, including such aspects as loudness, tonality, roughness, fluctuation strength, sharpness, and impulsiveness. The principal model was first published more than three decades ago as part of a doctoral thesis. Over the past few decades, the model has been refined and recently standardized in the international standard ECMA 418-2. This standard addresses several psychoacoustic parameters, including a new approach to time-varying loudness based on a nonlinear combination of partial tonal and noise loudness (as part of the tonality). This is the preferable approach because the loudness of tonal components (i.e., tonal loudness) may have a more pronounced impact on loudness perception than the loudness caused by other components (i.e., noise loudness). Other standardized parameters include psychoacoustic modulation analyses. These are roughness, which is employed to evaluate rapidly
Sottek, RolandBray, Wade
Wheel Force Transducers (WFT) are precise and accurate measurement devices that seamlessly integrate into any vehicle. They can be applied in numerous vehicle applications for both on-road and in laboratory settings. The instrumentation requires replacing an original equipment manufacturer (OEM) wheel with a custom WFT system which is specific to the wheel hub design. An ideal design will minimally impact a vehicle's dynamics, but the vehicle system is inherently modified from the mass of the measurement device. Research and technical documentation have been published which provide conclusions explaining reduction in the unsprung mass reduces dynamic wheel load. However, there doesn’t appear to be clear compensation techniques for how a modified unsprung mass can be related to the original system, thus allowing the WFT signals to be more accurate to the OEM wheel forces. An experimental study was performed on a prototype motorcycle to better understand these differences. An
Frisco, JacobLarsen, WilliamRhudy, ScottOosting, NicholasLaurent, Matthew
Over the past 30 years concerns about noise & vibration have become more critical in the design and manufacture of the automobile. Tools, both in physical testing and computer aided engineering have and continue to develop permitting more refined designs. Today’s customer can be very discerning when it comes to vehicle noises and vibrations. However, this is not a new concern for automotive customers or manufactures. This paper highlights the drive from automotive manufacturers to promote quiet, smooth and vibrationless operation of their products as well as some of the advances in vehicle component design over the past 100+ years. This is not an exhaustive study, but rather the intent is to bring to light the long history of noise and vibration in the automotive industry and its importance to the customers even in the infancy of the auto industry.
Kach, RaymondThompson, James
The proposed work performs the detailed investigation of material damping ratio for different Electronic Ignition Switch Module (EISM) used in two-wheeler automobiles. A Finite Element Method (FEM) based simulation model has been developed. The simulation is performed by matching the failure areas of critical components in the assembly with physical sinusoidal vibration based shaker table test. The results (particularly breakage) have been reproduced by utilizing different damping ratios for the assembly. The damping ratio parameter is further utilized to perform FEM based harmonic response analysis for different EISM and evaluate critical structural breakage zones. The breakage zones predicted by simulation are found to be aligned with breakage zones depicted by shaker table sinusoidal test results. The simulation outcomes are validated, specifically considering the damping ratio parameter. The FEM based harmonic response analysis has been performed for a particular acceleration
Shah, VirenKalurkar, ShantanuKumar, RahulKushari, SubrataMiraje, JitendraD, SureshParandkar, Parag
The advancement of civil supersonic aircraft is significantly constrained due to the intense noise generated by the shock waves that form during cruise, commonly referred to as the sonic boom. Due to these excessive noise levels, regulatory authorities currently ban supersonic flights over land. This study presents a comprehensive methodology to evaluate sonic booms in mid- and far-field regions, starting with a precise estimation of the near-field pressure signature produced by the shock wave system. While high-fidelity computational fluid dynamics (CFD) techniques typically provide near-field sonic boom predictions, specific propagation models must be used at greater distances, as CFD becomes prohibitively expensive beyond approximately 10 km. The focus of this research is a comparative analysis of a low-fidelity propagation approach, such as Whitham’s equation, and a high-fidelity CFD-based approach for assessing sonic boom propagation over medium range distances. The low-fidelity
Glorioso, AntimoFasulo, GiovanniPetrosino, FrancescoBarbarino, Mattia