Browse Topic: Fuel tanks

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Human-AI Interaction in Autonomous Medical Evacuation HelicoptersF-0081-2025-02825/20/2025
The vertical flight industry is on its way to a transformative era, with autonomous technologies set to alter aerial vehicle operations. While it seems certain that fully autonomous helicopters will eventually be deployed for a variety of missions, some high-stakes situations—like medical evacuations (MEDEVAC)—will for the foreseeable future demand human participation in the form of Emergency Medical Care-giving Crew. This study describes the testbed built to run and investigate hypothetical future situations in which a helicopter is autonomously piloted while a human medic with no aviation training, subjected to aviation and medical emergencies, manages patient care onboard. A total of 22 participants, with emergency medical technician certification, nursing or a medical board certification, were invited to run and evaluate the use of AI pilot (AP) in different scenarios of medical evacuation under the following emergencies: medical, empty fuel tank, pressure sensor miscalibration, and engine failure. A comprehensive evaluation of both objective and subjective performance metrics revealed that novice medical professionals could effectively execute medical evacuation operations in conjunction with an AI pilot, even during unforeseen circumstances. The analysis of response times unveiled distinct perspectives on how medics perceive and manage various emergency situations when an AP functions as a collaborative and effective team member.
Doda, Sanya, Feigh, Karen, Agbeyibor, Richard, Cortes, Carmen, Kolb, Jack, Magalhaes, Jose
Prediction and Validation of Sloshing and Fluid-Structure Interactions Using FPM for VTOL ApplicationsF-0081-2025-04005/20/2025
Accurate simulation of fluid-structure interactions (FSI) is critical for designing aircraft systems, particularly for applications involving fuel tank sloshing and large deformations. Traditional added mass methods often fail to capture the nonlinear and frequency-dependent behavior of these coupled systems. This study applies the Finite Pointset Method (FPM), a mesh-free computational fluid dynamics (CFD) technique, coupled with an explicit finite element solver, to predict complex FSI phenomena. Validation is performed using benchmark experiments, including a harmonic tank sloshing test and a guided plate ditching scenario, with results demonstrating strong agreement with measured pressures and structural responses. Additional validation on a composite fuel tank drop impact test confirms FPM's ability to model large deformations and rupture under dynamic loading. The findings highlight FPM's robustness and adaptability for aerospace FSI problems, offering a powerful alternative for virtual prototyping and certification workflows where conventional methods are insufficient.
Dwarampudi, Ramesh, Vaz, Ignatius
2024 Student Competition Undergraduate Winner: Georgia Tech Aerolay Design Multi-Mission Modular UAS for Disaster ReliefF-0081-2025-04265/20/2025
Unmanned Aerial Systems (UAS) are essential in disaster relief. VTOL UAS can take off and land in confined areas without infrastructure, efficiently accessing disaster zones for life-saving missions. The AeroLay, designed for disaster relief, delivers up to 54 kg and can loiter for 17.2 hours to relay cell signals. It features quick battery swaps and an accessible fuel tank for rapid redeployment.
Lutsenko, Aleksandr
Fluid-Structure Interaction of Fuel Tanks and Airframe Structures During a Crash EventF-0080-2024-11735/7/2024
This paper presents the results of a research and development (R&D) effort focused on fluid structure interactions between airframe structures and bladder type fuel tanks during a crash environment. During this R&D effort, fuel tank and surrounding structure crash impact tests were conducted using an innovative test configuration that allowed low-cost fabrication of test articles which represented several different design architectures. LS-DYNA models of the crash test article configurations were also developed and correlated with the tests data. Good correlation between the test data and LS-DYNA analysis results was achieved. The paper also includes recommendations for design of the airframe structures around the fuel tanks based on the fluid structure interaction insights gained from the crash tests and analyses.
Bolukbasi, Akif, Weisenburger, Richard
Aircraft Flame Arrestor Installation Guidelines and Test MethodsARP5776 (Current)8/26/2021
The scope of this document is to provide pertinent information on demonstrating the performance of Flame Arrestors, also known as Fuel Vent Protectors (FVPs), in preventing the propagation of a deflagration when the arrestors are subjected to aerospace-representative flames produced by the venting of flammable gas through the arrestor. Test procedures for two separate combustion-loading profiles are presented herein: The flame hold test condition, and the flame propagation test condition. For the flame hold test condition, the applicability of two separate critical flows is discussed in which one flow results in the greatest flame arrestor temperature and a second flow results in the greatest temperature of the surrounding structure. These guidelines are necessary for OEMs and fuel/vent system designers to validate the flame arresting-performance of the subassemblies comprising of the flame arrestors and relevant surrounding structures in an installation environment representative of the actual unique aircraft installation. Flame arrestors are components of the fuel system plumbing and, as such, are subject to the same requirements of other fuel system plumbing components. This document presupposes that the flame arrestor is properly installed; note that existing documentation (refer to ARP8615) provides detailed guidance for testing a flame arrestor as a component of a system, including standard requirements for testing the installation of a flame arrestor. Flame arrestors are installed on other aircraft system installations besides fuel vent systems. These include: fuel tank inerting system (within the distribution system at the tank entrance), electrical pump inlets and external aircraft drain masts. Although only the fuel tank vent system installation is specifically addressed in this document, portions of the detailed flame test procedures may be useful to qualify flame arrestors in other applications, e.g., the flame propagation test which is applicable to flame arrestors installed in the inerting system.
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Snowmobile Fuel TanksJ288_202106 (Current)6/10/2021
This SAE Standard establishes a uniform procedure and performance requirements for snowmobile fuel tanks.
Snowmobile Technical Committee
Fuel Level Point SensingAIR6325 (Current)11/30/2020
This report is intended to identify the various existing technologies used for a fuel level sensing system. In addition to sensing technologies, it describes the basic architecture of fuel level sensing systems and their association with fuel gauging system to increase integrity of fuel measurement and management. As the fuel level sensing system is generally based on electrical components within fuel tanks, a specific focus is made on fuel tank explosion safety protection. An overview of the capacitive fuel gauging operation can be found in AIR5691.
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Fuel Tank Dynamic Strain Measurement Using Computer Vision Analysis2020-01-09244/14/2020
Stress and strain measurement of high density polyethylene (HDPE) fuel tanks under dynamic loading is challenging. Motion tracking combined with computer vision was employed to evaluate the strain in an HDPE fuel tank being dynamically loaded with a crash pulse. Traditional testing methods such as strain gages are limited to the small strain elastic region and HDPE testing may exceed the range of the strain gage. In addition, strain gages are limited to a localized area and are not able to measure the deformation and strain across a discontinuity such as a pinch seam. Other methods such as shape tape may not have the response time needed for a dynamic event. Motion tracking data analysis was performed by tracking the motion of specified points on a fuel tank during a dynamic test. An HDPE fuel tank was mounted to a vehicle section and a sled test was performed using a Seattle sled to simulate a high deltaV crash. Multiple target markers were placed on the fuel tank. The motion of these markers was captured using high speed video cameras. The high speed videos were processed using the OpenCV computer vision library. Using OpenCV, the high speed videos were imported, and the position of the central location of each target marker was extracted frame by frame from the high speed videos. Once the position was known, the strain was computed using the change in relative position between two marker positions. Results of the testing showed that the acceleration-induced strain is low, generally less than the material yield strain. It was noted that reliable and accurate results require that the camera be placed normal to, or at a shallow angle to, the points being tracked. In addition, curved surfaces lead to limited fidelity of strain data due to the varying focal length of the points being tracked and measurement increased sensitivity. This method is similar to a “typical” tensile test in which displacement is tracked between two pre-established points on a sample. As such, the methodology was replicated on a tensile specimen to validate the methodology.
Fleming, Mark, Krishnaswami, Ram, Nakamoto, Kunihiro
Frequency Domain Analysis of 2-Wheeler Systems2020-01-04764/14/2020
Most automotive companies validate their vehicle designs by running vehicle on the durability proving grounds. Part fractures and collisions between two components are common failures observed during proven ground testing. Laboratory testing and FEA simulation are used to validate designs in the concept stage as it consumes less time and cost as compared to proven ground testing. The lab testing and simulation process both have their own limitations. It is difficult to incorporate effect of multi-direction input loading (x, y, z) with single direction loading in laboratory testing due to restrictions with electrodynamic shaker testing. However, in simulation, multi direction input can be easily incorporated but often actual vehicle measured test track data is not available in the early design stage. In the present work, Modern methodologies have been employed [ref 1, 2] in frequency domain to validate design in FEA simulation. First, relative random response calculation is performed for calculating the probability of collision between parts of motorcycle rear cowl. Second, multi-channel loading (x, y, z) on the front cowl is used to derive a simple single direction (surrogate) loading which has similar impact in terms of structural response (stress and fatigue). This derived single direction loading can be used efficiently in shaker testing. Third, a standard input load envelope is created in such a way that it includes all set of possible loading scenarios for a motorbike fuel tank assembly. This standard input load can be used at an early stage of design so that it helps in predicting component failure in FEA simulation.
Sethi, Mohit, Sharma, Ashish, Khare, Saharash, Sethi, Mohit, Sharma, Ashish, Khare, Saharash, Bishop, Neil, Kolar, Harsha
Simulation of Softening and Rupture in Multilayered Fuel Tank Material2019-28-255711/21/2019
Multi-layered, high-density polyethylene (HDPE) fuel tanks are increasingly being used in automobiles due to advantages such as shape flexibility, low weight and corrosion resistance. Though, HDPE fuel tanks are perceived to be safer as compared to metallic tanks, the material properties are influenced by service temperature. At higher temperatures (more than 80oC), plastic fuel tanks can soften, sag and eventually spill out the fuel, while the extreme cold (less than -20°C) can lead to potential cracking problems. Damage may also occur due to accidental drop while handling or due to an impact from a flying shrapnel. This can be catastrophic due to flammability of the fuel. The objective of this work is to characterize and develop a failure model for the plastic fuel tank material to simulate damage and enhance predictive capability of CAE for chassis and safety load cases. Different factors influencing the material properties such as service temperature, rate of deformation, state of stress etc. were considered to develop a characterization and modelling strategy for the HDPE fuel tank material. Samples cut-out from different regions of the fuel tank were subjected to various tests such as tensile test at different strain rates viz. 0.01/s, 0.1/s, 1/s, 10/s and 100/s, compression, shear, flexure and instrumented dart impact tests at different temperatures, -40°C, 23°C and 85°C. Simulation of damage was accomplished via progressive damage and failure modeling capability available in ABAQUS. Ductile damage initiation criteria and equivalent plastic displacement for damage evolution were considered. The parameters of the failure model were optimized using Design for Six Sigma (DFSS) principles. The material model was validated by comparing simulation results with test at coupon and component levels.
R L, Vijaya Kumar, Tripathy, Biswajit, Radhakrishnan, Jayaraj
Automotive Engineering: October 201919AUTP1010/1/2019
Conti suits up A team of young innovators aims to transform a critical piece of safety equipment - and create new business - through collaboration. Casting around for lightweight The U.K.'s Grainger & Worrall is introducing and perfecting "new and imaginative" casting technologies. Optimizing NVH for EVs Unique acoustic and harmonic challenges require an integrated approach to simulation and analysis. An expert at Adaptive Corp. explains. The new gas tank: Constellium readies its first OEM EV battery tray Global Tier-1 aluminum specialist Constellium's first OEM EV battery enclosure is a far cry, engineering-wise, from the century-old fuel tank. Editorial Losing the plot of the Engineering story? Supplier Eye Critical decisions for the 2020s What We're Driving Honda ready with new injury-reducing airbag Continental Tire rolls towards a smart-and-connected future Cutting weight seen as less vital for automated and shared vehicles GKN spreads premium propshaft tech to quiet pickup cabins Roush opens Advanced Durability Lab Frankfurt with an 'E' New-generation Nissan Versa breaks for higher ground What's Online Q&A Interview with Magna CTO Swami Kotagiri
Unmanned Helicopter DroneTBMG-3535810/1/2019
UAVOS Inc. Mountain View, CA 650-584-3176 www.UAVOS.com
Analysis of a Coupling System of Aircraft Environmental Control and Fuel Tank Inerting Based on Membrane Separation2019-01-18959/16/2019
This paper raises a coupling system of aircraft environmental control and fuel tank inerting based on membrane separation. The system applies a membrane dehumidifier to replace water vapor removal unit of heat regenerator, condenser and water separator, which is widely used in conventional aircraft environmental control system (ECS) nowadays. Water vapor can travel across the membrane wall under its pressure difference without phase change, so the dehumidification process consumes no cooling capacity as traditional ECS and the cooling capacity of the new system increases. This paper first compares the thermodynamic properties of ECS based on membrane dehumidification and the traditional ECS based on condensation. The results show that the membrane dehumidification system has larger cooling capacity and lighter weight. For a given cooling capacity requirement, the membrane dehumidification system can use less bleed air since the enthalpy of the outlet air is lower. Besides, the fuel tank inerting system also uses an air separation module to produce nitrogen enriched air based on membrane separation. After the air is dehumidified in membrane dehumidification ECS, its parameters meet the requirement of membrane air separation module. Thus, it is reasonable to combine the two systems together. This paper conducts a simulation analysis of the coupling system. Comparing with the conventional four wheel high pressure de-water ECS and fuel tank inerting system used onboard nowadays, the coupling system has simpler structure and lighter weight. The simulation results show that the coupling system can decrease the fuel penalty by 139.67kg each pack.
Yuan, Weixing, Zheng, Yan, Hou, Jiaqi
Photogrammetric Frost Roughness Measurements in Cold-Soaked Conditions2019-01-19706/10/2019
Cold-soaked fuel frost (CSFF) is a form of aircraft wing contamination that occurs when a vehicle caries sufficient fuel for multiple trips or take-offs and landings. Following the first trip, which may reach altitudes above 10,000 m (33,000 ft), the fuel for the subsequent trips is carried in the wing tanks and may reach temperatures below -25 °C. In certain times of the year at some airports, temperatures and humidity levels will form CSFF on the aircraft wing surfaces over the fuel tanks. Unless an exemption is granted for the specific aircraft model, aircraft are not allowed to takeoff if the wing surfaces are contaminated by frost. Because aircraft operators desire to minimize vehicle time spent at airports, aircraft manufacturers are expected to pursue designs that safely operate with CSFF at takeoff and to pursue certification exemptions for aircraft models enabling CSFF takeoffs. To assist manufacturers in the design of future aircraft and to assist regulators in evaluating certification exemption requests, more information about frost roughness characteristics and evolution in CSFF conditions is required. However, because of the material and optical properties of frost, measuring CSFF properties using traditional roughness measurement presents challenges. For this investigation, a photogrammetric approach based on “structure-from-motion” algorithms traditionally employed in aerial surveying was developed to characterize the evolution of CSFF roughness. Using the approach, measurements of frost roughness evolution were performed in the Baylor Frost Tunnel (BFT) for two basic air temperature, humidity, surface temperature, and velocity conditions with frost time up to two hours. An analysis of variance approach was used to determine the sensitivity frost growth rates to the environmental conditions. The resulting measurements demonstrate different evolution histories with air velocity and air temperature being the most important factors governing roughness growth.
Miyauchi, Taber, McClain, Stephen T., Zhang, Tongxin, O'Neal, Dennis L., Riley, James T.
A Quasi-Steady Diffusion-Based Model for Design and Analysis of Fuel Tank Evaporative Emissions2019-01-09474/2/2019
In this paper, a fuel tank evaporation/condensation model was developed, which was suitable for calculation of evaporative emissions in a fuel tank. The model uses a diffusion-controlled mass transfer approach in the form of Fick's second law in order to calculate the average concentration of fuel vapor above the liquid level and its corresponding evaporation rate. The partial differential equation of transient species diffusion was solved using a separation of variables technique with the appropriate boundary conditions for a fuel tank. In order to simplify the solution, a quasi-steady assumption was utilized and justified. The fuel vapor pressure was modeled based on an American Petroleum Institute (API) procedure using either a distillation curve or a Reid Vapor Pressure (RVP) as an experimental input for the specific fuel used in the system. The advantage of this model compared to other published models is the fact that it is a non-equilibrium model that considers the effects of mass transfer between phases. The model was validated with transient data for both short (drive cycle) and long (diurnal cycle) durations. In addition, evaporation and condensation cycling simulations were performed.
Ghadirian, Emad, Brown, Jonathan, Wahiduzzaman, Syed
Simulation and Experimental Study of Filler Pipe of Automobile Fuel Tank Based on ORVR Technology2019-01-08004/2/2019
A filler pipe of vehicle fuel tank has been simulated and optimized about refueling smoothness which is based on On-board Refueling Vapor Recovery (ORVR). Both liner of filler pipe and straight pipe section at the bottom of filler pipe have been studied. The results show that extending the end of the liner to the first elbow of the filler pipe can effectively control the phenomenon of fuel spit-back in the refueling process and promote the refueling process to be smoother. Compared with the bottom of the original filler pipe, extending the bottom length to 100 mm, adding the upper open form in check valve structure, the result shows that in the process of refueling, dynamic fluid sealing can be formed to meet the design requirements. After that, the fuel system bench test was carried out, and conducted a bench test to verify the simulation results. The final filling in the tank is 50.8 L, which meets the 85% filling requirement of the regulations; the canister has gain 67.38 g, the emission result is 0.0141 g/L, which meets the requirements of the regulation of 0.05 g/L.
Fu, Tieqiang, Zhong, Chongzhi, Zhang, Taiyu, Meng, Shuaiqi, Wu, Ke
Optimized Fuel Tank Sender ClosureJ2587_201903 (Current)3/8/2019
This practice describes recommended performance requirements of fuel tank closures used in conjunction with fuel level senders and fuel delivery systems. It provides guidelines that assure interchangeability and compatibility between fuel tanks and fuel pump/sender closure systems without specifying a specific closure system design. These systems may be used in rigid fuel tank systems made of plastic or metal. Complete details of specific designs shall be established by mutual agreement between customer and supplier. The dimensions and performance requirements are selected to optimize a The closure system, durability and reliability with respect to — Vehicle SHED measurements — Fuel system / crash integrity — LEV – II useful life b Assembly and service ease and reliability c Packaging of fuel tanks and their sending units d Interchangeability of sender closures between various fuel tank designs
Fuel Systems Standards Committee
Multirole Utility HelicoptersTBMG-337752/1/2019
Airbus Helicopters Marignane Cedex, France +33 (0)4 42 85 60 51
Q&A19AUTP08_211/1/2019
Sean Stanley is one of a new generation of motorcycle engineers who are as fluent in battery cooling and electronics integration as their predecessors were in optimizing cam profiles and compression ratios. As Harley-Davidson's EV Systems chief engineer, Stanley, along with EV Platform chief Glen Koval and their teams, have brought the 2020 LiveWire e-bike from a bold concept in 2011 to production, which is getting underway at H-D's York, Pennsylvania, assembly plant. LiveWire is nothing like your granddad's Shovelhead, aside from the brand name on the faux ‘gas tank.’ There are five ECUs on board controlling seven rider-selectable and customizable ride modes. Rear-wheel lift mitigation is managed by a 6-axis inertial measurement unit (IMU). The 15.5-kWh Samsung SDI lithium-ion battery, liquid cooled 78-kW (108-hp) Magneti-Marelli permanent-magnet motor, 1400-watt SAE J1772 ‘Combo’ charging setup, 4.3-in. (109-mm) color thin-film display, and hollow-cast aluminum ‘exoskeleton’ chassis, represent just some of the topflight systems engineering that is the hallmark of this novel bike.
Development of Horizontal Water Cooled Diesel Engine to Achieve High Power Density2018-32-006410/30/2018
The horizontal water cooled diesel engine has a structure including all component parts such as a fuel tank that are necessary to drive engine, and is often a single cylinder engine. It is mounted on many applications such as power tiller and water pump because of high general versatility of installing owing to belt drive. It has a simple structure because of single cylinder, and is active mainly in Southeast Asia. At the same time, the market requires this type of engine higher power while a compact structure is also required from the viewpoint of easy to supply and use. In other words, “High power density” that is improving the output per body size has been required. We have responded to the demand of “High power density” by increasing output without changing the engine size. In order to keep the engine size, we have been enlarging displacement by using our peculiar stroke-up expertise and original bore-up contrivance. In addition to those techniques, we introduced analytic technology for early approach to optimal solution. While we had used deep bowl combustion chamber for emphasizing medium and low speed torque, we adopted shallow dish combustion chamber because we shortened the compression height of piston for stroke-up. We utilized combustion analysis so as to approach optimal solution early because we have no base data of shallow dish combustion chamber. In addition, we used stress analysis to optimize the hardening of crankshaft. As written above, by incorporating analytic technology in addition to conventional development methods, we have been supplying correct size engines speedily in response to requirement of market. In this paper, we introduce the techniques that we adopted in order to realize the high power density.
Komai, Yoshinobu, Takashima, Yusuke, Fujiwara, Tsukasa, Okamoto, Hisao, Kawahara, Minoru
Multi-Layer Wireless Sensor Construct for Use at Electrically Conductive Material SurfacesTBMG-297027/1/2018
NASA's Langley Research Center has developed a SansEC Sensor technology for use with aerospace fuel delivery systems. The SansEC technology is a patented and proven platform for multiple applications, including fluid level measurement. The platform utilizes a flat coil geometry antenna operated at its resonant frequency to measure dielectric properties or property changes of materials near the coil. The technology is well suited for situations where wireless, powerless, or non-contact measurements are needed with high sensitivity and accuracy. NASA Langley Research Center is seeking industrial partners/licensees to commercialize this technology. The research team at NASA Langley is available to assist with further development.
An Experimental Study of the Impact of Underbody Roughness on the Instantaneous Wake Flow Topology behind a Truck Geometry2018-01-07144/3/2018
The turbulent wake behind a truck is responsible for a considerable proportion of the total aerodynamic drag. There is evidence to suggest that the underbody flow affects the wake topology, although this interaction is not well understood. Typical truck trailer underbodies are geometrically very complex and have a range of bluff bodies - such as the wheel and axle assembly, structural beams or the secondary fuel tank for refrigerated trucks - attached. These components block the underbody flow and erode its momentum. However, most of the previous studies of the wake flow have used models with clean underbodies. It is thus uncertain whether the wake shapes found by these studies accurately represent the wake topology behind a real truck with a detailed underbody. The aim of this study is therefore to investigate whether aerodynamic studies working with simplistic underbodies may observe a different wake pattern to those studies that correctly replicate the aerodynamic effects of a realistic underbody. This work uses two models. The first is a simple 1/10th scale model with the basic geometry and aspect ratio of a generic HGV. An underbody roughness pattern, which simulates the effect of the geometric complexity found in typical underbodies and that represents the standard blockage caused by common underbody components, is attached to the underside of the model. The structure of the wake behind the model is studied when the roughness pattern covers an increasing proportion of the total underbody. The observations made are compared to those seen for a configuration with a smooth underbody. The second model consists on a full 1/10th scale truck model with a detailed underbody and rotating wheels. Testing is conducted in a water tow tank, which establishes correct ground conditions. The facility operates at a Reynolds Number of approximately Re = 6.9 x 105. Optical access into the underbody and the near wake is possible through the clear working section of the facility. Stereoscopic Particle Image Velocimetry is used to analyse the flow field. It is found that underbody blockage and / or roughness considerably affects the wake topology and leads to a greater interaction between the low momentum flow in the wake and the higher momentum flow around it. Underbody roughness also increases the size of the region where the low momentum flow is concentrated, which expands laterally outwards away from the model center plane to a greater extent than for the smooth configuration. It is expected that the impact of underbody components on the wake flow structure may also affect the aerodynamic drag associated to the wake. This emphasizes the importance of improving the understanding of the interaction between the underbody and wake flows with drag reduction objectives in mind.
Vallina Garcia, Isabel, Babinsky, Holger
Real World Performance of an Onboard Gasoline/Ethanol Separation System to Enable Knock Suppression Using an Octane-On-Demand Fuel System2018-01-08794/3/2018
Higher compression ratio and turbocharging, with engine downsizing can enable significant gains in fuel economy but require engine operating conditions that cause engine knock under high load. Engine knock can be avoided by supplying higher-octane fuel under such high load conditions. This study builds on previous MIT papers investigating Octane-On-Demand (OOD) to enable a higher efficiency, higher-boost higher compression-ratio engine. The high-octane fuel for OOD can be obtained through On-Board-Separation (OBS) of alcohol blended gasoline. Fuel from the primary fuel tank filled with commercially available gasoline that contains 10% by volume ethanol (E10) is separated by an organic membrane pervaporation process that produces a 30 to 90% ethanol fuel blend for use when high octane is needed. In addition to previous work, this paper combines modeling of the OBS system with passenger car and medium-duty truck fuel consumption and octane requirements for various driving cycles. Medium duty driving cycles were included; HHDDT cruise mode for long-haul heavy truck cruising and HTUF 4 for delivery truck duty. Commercial vehicle modeling was done under unloaded, half and fully loaded conditions. Additionally, for the first time, transient separator performance and effective separation limits were included in the evaluation. Separator start-up, and membrane selectivity decrease achievable real-world fuel economy from what can be achieved with two separate tanks: one with gasoline, the other with ethanol. However, using the fuel separation system, the reduction in fuel economy is modest compared to a two tank system with pure ethanol while the need to fill a second tank is removed. Fuel efficiency gains compared to equivalent-performance current engines, including real world limitations ranged from 17.5-30% with commercial gasoline that includes 10% ethanol as base fuel.
Kasseris, Emmanuel, Heywood, John B., Seitz, Scott, Kolakaluri, Ravi
Influence of Vehicle Operators and Fuel Grades on Particulate Emissions of an SI Engine in Dynamic Cycles2018-01-03504/3/2018
With the implementation of the “Worldwide harmonized Light duty Test Procedure” (WLTP) and the highly dynamic “Real Driving Emissions” (RDE) tests in Europe, different engineering methodologies from virtual calibration approaches to Engine-in-the-loop (EiL) methods have to be considered to define and calibrate efficient exhaust gas aftertreatment technologies without the availability of prototype vehicles in early project phases. Since different types of testing facilities can be used, the effects of test benches as well as real and virtual vehicle operators have to be determined. Moreover, in order to effectively reduce harmful emissions, the reproducibility of test cycles is essential for an accurate and efficient application of exhaust gas aftertreatment systems and the calibration of internal combustion engines. In this paper, the influence of different human drivers on the particle count of a passenger car with a small turbocharged three-inline-cylinder gasoline engine with intake-manifold fuel injection is presented. Furthermore, the effects of one human driver in comparison to a virtual driver regarding the reproducibility of the test results are shown. In this setup several particulate measurement systems with different measurement principles are taken into account to validate the results. In the second part of the paper, including the same engine and measurement systems, the effects and influences of seasonal RON 95 gasoline fuel qualities (winter and summer) on the size distribution (5,6-560 nm) and the particulate count are discussed. With the introduction of the Euro 6d emission standards, there is no longer a legal specification in place for the fuel to be used for RDE emission testing. Hence, it must be considered that due to seasonal climate changes, specifically designed fuels are sold at regular gas stations. Although summer and winter fuels are supposed to guarantee the same physical properties, they differ in composition which can lead to considerable differences in particulate emissions. To avoid a mixing of the different climate-dependent fuel types during the test program, the fuel tank has been extensively flushed before refilling it with the next test fuel. As prescribed all fuels were bought at public gas stations and have been analyzed by a third-party laboratory to guarantee the immaculateness of each fuel type.
Guse, Daniel, Roehrich, Henning, Lenz, Martin, Pischinger, Stefan
Recommended Practices for CNG Powered Medium and Heavy-Duty TrucksJ2406_201802 (Current)2/12/2018
This SAE Recommended Practice provides guidance for the construction, operation, and maintenance of CNG powered medium and heavy-duty trucks. The intent of this document is to cover TRUCKS (6350 kg (14 001 gvw pounds) and above) and specifically excludes passenger vehicles such as: buses, recreational vehicles, motor homes and/or passenger vehicles which may incorporate a truck chassis in their construction.
Truck and Bus Powertrain Committee
A Mathematical Model for the Vapour Composition and Flammability of Gasoline - Diesel Mixtures in a Fuel Tank2017-01-240710/8/2017
Low Temperature Combustion using compression ignition may provide high efficiency combined with low emissions of oxides of nitrogen and soot. This process is facilitated by fuels with lower cetane number than standard diesel fuel. Mixtures of gasoline and diesel (“dieseline”) may be one way of achieving this, but a practical concern is the flammability of the headspace vapours in the vehicle fuel tank. Gasoline is much more volatile than diesel so, at most ambient temperatures, the headspace vapours in the tank are too rich to burn. A gasoline/diesel mixture in a fuel tank therefore can result in a flammable headspace, particularly at cold ambient temperatures. A mathematical model is presented that predicts the flammability of the headspace vapours in a tank containing mixtures of gasoline and diesel fuel. Fourteen hydrocarbons and ethanol represent the volatile components. Heavier components are treated as non-volatile diluents in the liquid phase. The non-ideality of the blends of hydrocarbons and ethanol is accounted for using activity coefficients. Predictions for dry vapour pressure equivalent (DVPE), vapour phase composition and flammability are compared to experimental data for 12 mixtures of 4 base gasolines, some containing alcohol, a single diesel fuel and various quantities of additional ethanol. A 5% fuel tank fill level and a total tank pressure of 1 atmosphere were used. The model predicted DVPE for both base gasolines and dieseline blends that were within 2-4% of measured values. Predicted upper temperature limits of flammability were consistently 5-10°C higher than measured in this apparatus. The discrepancy was attributed mainly to the impact of downward flame propagation in this apparatus, compared to upward propagation used in flammability data found in the literature and used in the model.
Bardon, Michael, Pucher, Greg, Gardiner, David, Ariztegui, Javier, Cracknell, Roger, Hamje, Heather, Pellegrini, Leonardo, Rickeard, David
Using System Simulation to Manage Increasing Thermal Loads on Aircraft Fuel Systems17AERP08_036/1/2017
Today's modern military fighter jets are like “a flying thermos bottle” according to Steve Iden, AFRL Invent Program Manager [1]. Many engineers have been saddled with trying to put the thermal loading constraints of these fighter jets on ice. This places increasing demands on utilizing the fuel system as a heat sink to dissipate thermal loads coming from onboard electronics, oil and hydraulic systems, avionics bay cooling, and weapons modules. Engineers today are looking to simulation to help tackle these design challenges, and they have more power than ever with simulating fuel systems to evaluate feasible system designs with given requirements on thermal power loading, fuel capacity, and tank geometry. With a given set of key performance metrics and limits on a design, the design space can be quickly explored to find optimum metrics such as flight mission duration or required component sizing to meet thermal load requirements.
Thermoplastic Enclosure for a High Voltage Battery System2017-01-11903/28/2017
As electrified powertrains proliferate through original equipment manufacturer vehicle offerings, the focus on system cost and weight reduction intensifies. This paper describes the development and evaluation of a High Voltage (HV) battery system enclosure molded from High Density Polyethylene (HDPE) to deliver substantial cost and weight opportunities. While previous HV battery system enclosure alternatives to steel and aluminum focus on thermoset composites and glass filled polypropylene, this solution leverages select HDPE design techniques established for fuel tanks and applies them to an HV battery system. The result is a tough, energy absorbing structure, capable of hermetic sealing, which simplifies manufacturing by eliminating nearly all fasteners. The authors evaluate performance with respect to crashworthiness, fire resistance, electro-magnetic compatibility and other challenges; using comparative research, computer analysis, and physical testing to demonstrate the system capabilities. The result is a compelling argument for employing HDPE to enclose and protect a HV battery system, yielding cost and weight reduction opportunities over conventional solutions.
Maguire, Patrick, Baek, Hyung, Liptak, Stephen, Lomax, Olivia, Palma, Rodolfo, Zhang, Yi
Use of V-Cycle Methodology to Develop Mechatronic Fuel System Functions2017-01-16143/28/2017
As electronics make their way into the fuel system, a shift in problem solving can be seen. Previously high risk items were tackled mainly through proving component durability and decreasing the statistical odds of the problem occurring. With an electronically controlled system however it is possible and necessary to define degraded modes, in the event that certain components fail, in order to provide at least a limited functionality for the customer. This paper will discuss some different use cases, and how embedded software can be used to improve functionality over a passive system.
Hill, David, Op de Beeck, Joel, Baja, Mihai, Djemili, Issam, Reuther, Paul, Sutra, Iris
The Root Cause Analysis of Steel Fuel Tank Cracking at a Fatigue Point and Test Method Development of Durability2017-01-03933/28/2017
Fuel tank in vehicle must hold the fuel in a stable way under any driving condition. However, the fuel tank might not conserve the fuel firmly in case a crack emerged while the fuel tank is exposed to different driving condition. Basically, when the engine is in purging at a normal ambient temperature before fuel boiling, the pressure inside the fuel tank decreases. However, the pressure inside a fuel tank increases while a vehicle is driven at extreme hot ambient temperature as fuel is boiling. This repetitive pressure change in the fuel tank comes with fuel tank’s physical expansion and shrink, which would cause a damage to the fuel tank. The main purpose of this research is to investigate the root cause of why fuel tank cracks at a fatigue point. We also aim to set up the method of how to test durability of the fuel tank in association with the pressure inside the tank.
Kim, Keunsoo
Approaches of NVH Improvements for Fuel Pump Noise Issues2017-01-04423/28/2017
With the increasing expectation of customer for a quiet and comfortable ride, automobile manufacturers need to continuously work upon to improve automobile powertrain NVH. Today’s customer has become so aware of vehicle related noises that in-tank fuel pump noise is no exception to the checklist of evaluating cabin NVH. In-tank fuel pump, that is responsible for delivering the fuel from fuel storage tank to delivery rail, uses an electric driven motor. The rotating parts such as rotor, etc. produce vibrations that may traverse to tank body & subsequently vehicle body. Since noise is essentially an audible vibration at its root, these structure borne vibrations may be perceived as noise inside passenger cabin. Additionally, the noise may also be produced by fuel flow pulsations if transferred through piping to vehicle body. This paper focuses on various approaches to reduce the fuel pump generated noise heard inside passenger cabin. Some of the approaches used for the aforementioned are: dampening or isolating source vibrations, changing modal/frequency response behavior, reducing/eliminating the resonance factor in the traversed medium, etc. These approaches have been formulized based on various iterations conducted at fuel pump level, fuel tank level and piping layout. The results were gauged by subjective feeling as well as objective data measurement. Furthermore, the paper also touches upon the use of CAE tools to identify resonating points.
Aneja, Harchetan Singh, Tripathi, Manas, Singh, Harmeet, Parmar, Aashish
High Frequency Sloshing - Energy Dissipation and Viscous Damping through CFD2017-01-13173/28/2017
Liquid sloshing is an important issue in ground transportation, aerospace and automotive applications. Effects of sloshing in a moving liquid container can cause various issues related to vehicle stability, safety, component fatigue, audible noise and, liquid level measurement. The sloshing phenomenon is a highly nonlinear oscillatory movement of the free-surface of liquid inside a container under the effect of continuous or momentarily excitation forces. These excitation forces can result from sudden acceleration, braking, sharp turning or pitching motions. The sloshing waves generated by the excitation forces can impact on the tank surface and cause additional vibrations. For the loads with the frequencies between 2 to 200 Hz, the structural fatigue failure is a major concern for automotive applications. Also, for the dimensions associated with automotive, the fundamental frequency of the sloshing waves is usually a fraction of a Hertz, so frequencies above 2 Hz constitutes “high frequencies” for sloshing. Sloshing within liquid tanks causes rapid energy dissipation at the fluid resonant modes. Due to viscous effects (friction) the amplitude of the waves decreases over time when external excitation is stopped (liquid damping). The present work evaluates the liquid viscous damping through Computational Fluid Dynamics (CFD) at “high frequency” excitation conditions in automotive fuel tanks. These damping coefficients are important parameters for the accurate evaluation of the structural durability of fuel tank and its components. In this study, different liquid levels and liquid types were evaluated at numerous excitation frequencies in the range of 2-20 Hz. It was found that the excitation frequency of 10 Hz matches with the natural frequency of the systems with similar liquids (gasoline and water) in the particular container under study at 25% fill level. This can be observed by analyzing the Kinetic Energy (KE) after stopping the excitation. The dimensional damping constant tends to be proportional to the dynamic viscosity of the liquid.
Blas Martinez, Luis Felipe, Palma, Rodolfo, Gomez, Francisco, Vaishnav, Dhaval, Canales, Francisco
Characterization of Spray Evaporation and Mixing Using Blends of Commercial Gasoline and Diesel Fuels in Engine-Like Conditions2017-01-08433/28/2017
Recent studies have shown that the use of highly premixed dual fuel combustion reduces pollutant emissions and fuel consumption in CI engines. The most common strategy for dual fueling is to use two injection systems. Port fuel injection for low reactivity fuel and direct injection for high reactivity fuel. This strategy implies some severe shortcomings for its real implementation in passenger cars such as the use of two fuel tanks. In this sense, the use of a single injection system for dual fueling could solve this drawback trying to maintain pollutant and efficiency benefits. Nonetheless, when single injection system is used, the spray characteristics become an essential issue. In this work the fundamental characteristics of dual-fuel sprays with a single injection system under non-evaporating engine-like conditions are presented. In particular, maximum liquid length and vapor penetration behavior of five blends of commercial gasoline and diesel were tested when injected through a single-hole nozzle into an optical engine under non-reactive conditions. The liquid and vapor penetration were determined with Mie scattering and Schlieren high-speed imaging techniques for different operating in-cylinder thermodynamic conditions and injection pressures. Experimental results confirm that the liquid length is increasing with the density of the blend and that injection pressure has little effect on the liquid length. A fuel with high density within the blends controls the liquid phase length. Blends with the higher gasoline volume percentage vaporize easily in relative terms. Experiments prove that the vapor penetration is a function of the momentum flux, therefore fuel density does not affect the vapor penetration.
Pastor, Jose, Garcia-Oliver, Jose M, Garcia, Antonio, Nareddy, Varun Reddy
CFD Driven Parametric Design of Air-Air Jet Pump for Automotive Carbon Canister Purging2017-01-13163/28/2017
A jet pump (also known as ejector) uses momentum of a high velocity jet (primary flow) as a driving mechanism. The jet is created by a nozzle that converts the pressure head of the primary flow to velocity head. The high velocity primary flow exiting the nozzle creates low pressure zone that entrains fluid from a secondary inlet and transfers the total flow to desired location. For a given pressure of primary inlet flow, it is desired to entrain maximum flow from secondary inlet. Jet pumps have been used in automobiles for a variety of applications such as: filling the Fuel Delivery Module (FDM) with liquid fuel from the fuel tank, transferring liquid fuel between two halves of the saddle type fuel tank and entraining fresh coolant in the cooling circuit. Recently, jet pumps have been introduced in evaporative emission control system for turbocharged engines to remove gaseous hydrocarbons stored in carbon canister and supply it to engine intake manifold (canister purging). Naturally aspirated engines use vacuum pressure inside the intake manifold for canister purging. However, turbocharged engines operate at or above atmospheric pressure. Hence, a jet pump is used in which the high pressure compressed air from the turbocharger flows through a nozzle and creates necessary vacuum to facilitate canister purging. This paper describes the CAE driven parametric design process of such a jet pump. Flow velocity through nozzle is often in high subsonic or supersonic regime. Hence, a CAE method needs to consider coupled flow along with local mesh refinements and additional boundary layer cells. For subsonic regime, results from the coupled flow solver were nominally same as less resource intensive segregated flow solver. However, for supersonic regime, the difference in performance was found to be up to 10% due to air compressibility effects. The paper also covers details about the CAE-test correlation. The validated CAE method is employed to understand the effect of numerous geometrical parameters such as: nozzle diameter, area ratio of throat and nozzle, diffuser length, nozzle shape and purge port diameter. Performance curves (purge flow vs. turbocharger pressure) are developed for each of these parameters. Purge flow was specifically found to have a strong dependency on the area ratio and purge port diameter. Optimum area ratio of 0.04 and larger purge port provided significant performance improvement. In conclusion, this paper aims to develop performance curves and explore effect of several geometrical parameters on the performance of the jet pump to add to the existing knowledge base especially the automotive literature.
Vaishnav, Dhaval, Ehteshami, Mohsen, Collins, Vylace, Ali, Syed, Gregory, Alan, Werner, Matthew
Unsteady Three-Dimensional Computations of the Penetration Length and Mixing Process of Various Single High-Speed Gas Jets for Engines2017-01-08173/28/2017
For various densities of gas jets including very light hydrogen and relatively heavy ones, the penetration length and diffusion process of a single high-speed gas fuel jet injected into air are computed by performing a large eddy simulation (LES) with fewer arbitrary constants applied for the unsteady three-dimensional compressible Navier-Stokes equation. In contrast, traditional ensemble models such as the Reynolds-averaged Navier-Stokes (RANS) equation have several arbitrary constants for fitting purposes. The cubic-interpolated pseudo-particle (CIP) method is employed for discretizing the nonlinear terms. Computations of single-component nitrogen and hydrogen jets were done under initial conditions of a fuel tank pressure of gas fuel = 10 MPa and back pressure of air = 3.5 MPa, i.e., the pressure level inside the combustion chamber after piston compression in the engine. An important point of the present study is to obtain clear evidence for Hamamoto’s experimental data that the penetration length of a light hydrogen gas jet of low density is nearly the same as that of relatively heavy gas jets such as nitrogen or carbon dioxide. It is confirmed that the computed penetration lengths of hydrogen and nitrogen gas jets injected into air are nearly the same, although hydrogen has very small inertia due to its low density. It is also stressed that computational results agree fairly well with Hamamoto’s empirical data on penetration lengths and diffusion area in the direction normal to the jet axis. Moreover, computations based on the present LES also clarify a physical mechanism underlying combustion instability in engine experiments conducted by Takagi et al., although the RANS is relatively difficult to reveal instability of unsteady flow field.
Konagaya, Remi, Naitoh, Ken, TSURU, Kohta, Takagi, Yasuo, Mihara, Yuji
Simulating and Analyzing Flow for an Air-to-Air Refueling SystemTBMG-264392/1/2017
Long-range bombers may have missions halfway around the world. Fighter jets may have to stay in the air longer than their relatively small fuel tanks will allow, or may find they have exhausted their fuel unexpectedly, such as during supersonic flight or evasive maneuvers. In these situations, large tanker aircraft are deployed that carry sufficient fuel to refill several smaller aircraft in a single mission (Figure 1). The task of injecting volatile jet fuel from one aircraft to another while both are moving at high speed and altitude is fraught with risk.
Simulating and Analyzing Flow for an Air-to-Air Refueling System17AERP02_042/1/2017
Long-range bombers may have missions halfway around the world. Fighter jets may have to stay in the air longer than their relatively small fuel tanks will allow, or may find they have exhausted their fuel unexpectedly, such as during supersonic flight or evasive maneuvers. In these situations, large tanker aircraft are deployed that carry sufficient fuel to refill several smaller aircraft in a single mission (Figure 1). The task of injecting volatile jet fuel from one aircraft to another while both are moving at high speed and altitude is fraught with risk.
Dynamic Analysis of Motorcycle Fuel Tank using Virtual Fluid Mass Methodology(VFM)2017-26-02631/10/2017
This paper describes an investigation of the suitability of FE analysis using the virtual fluid mass (VFM) in fuel tank validation. It produces a mass matrix which represents the fluid coupled to a boundary consisting of structural elements and other effects, such as free surfaces, planes of symmetry and infinite fluids. The incompressible fluid produces a mass matrix defined with full coupling between accelerations and pressures on the flexible structural interfaces. This capability is used to model fuel tank with fuel filled inside. Hence, using the VFM method modal analysis is performed keeping the fuel tank 90% filled and results are compared with physical testing. The VFM method is much more reliable and accurate than the NSM or density adjusted method. The modal frequencies obtained in VFM technique are in proximity with the physical testing results. Further, the fuel tank and its mountings are evaluated for frequency response analysis with excitation in vertical direction.
Palve, Vikas, Bhavsar, Prashant, Kumbhar, Shyamsundar, Roy, Gyanendra
Fuel Tank for Liquefied Natural GasTBMG-261601/1/2017
NASA’s Marshall Space Flight Center has developed a new composite vessel technology that is suitable for use as a liquefied natural gas (LNG) fuel storage tank for alternative fuel vehicles. This technology uses an improved composite over-wrapped technology to produce a pressure vessel that is simple to use, robust, and capable of withstanding high pressures. It is also lightweight and low cost. This technology shows great potential to help the United States and other countries move toward a cleaner environment while allowing for efficient use of a more natural fuel in many different applications.
Safety Drain System for Fluid ReservoirTBMG-2602212/1/2016
Researchers at NASA’s Marshall Space Flight Center have developed a system that reduces the entrapment risks associated with a pool or spa’s recirculation drain. The technology prevents hazards caused by suction forces on the body, hair, clothing, or other articles. Employing a novel configuration of drainage openings along with parallel paths for water flow, the system redistributes force over a much larger area, minimizing suction force at any localized area. With more efficient drainage and recirculation, the device improves performance, increases safety, and decreases operating costs. The technology can also provide thorough chemical mixing, which improves processes in systems and allows continued operation in the event of localized debris clogging a portion of the recirculation area. All of these benefits come without a protrusive drain cover, leaving the area safe and aesthetically pleasing.
A Gasoline Fuelled Pre-Chamber Ignition System for Homogeneous Lean Combustion Processes2016-01-217610/24/2016
Pre-chamber ignition systems enable the combustion of homogeneous lean mixtures in internal combustion engines with significantly increased thermal efficiency. Such ignition systems provide a much higher ignition energy compared to a common spark ignition by burning a small portion of the charge in a separate chamber, generating multiple ignition sites in the main combustion chamber and increasing the turbulent flame speed. Pre-chamber ignition systems are commonly used in large natural gas engines but the integration in automotive engines is not feasible so far due to the lack of suitable fuelling systems needed to keep the pre-chamber mixture stoichiometric at lean operation of the engine. Based on preliminary investigations we developed an ignition system with fuelled pre-chamber for automotive engines utilizing the available space for the conventional spark plug. These investigations proved the thermal stability and function of the system up to a specific power of 100 kW/l and a speed of 12500 rpm. The fuelling system saturates air with fuel vapour and injects this mixture time-controlled into the pre-chamber. The already available fuel tank ventilation system in Otto-engine powered cars can provide such an air-gasoline-vapour mixture. Further, the system uses an inexpensive low pressure solenoid valve to control the pre-chamber enrichment. The prototype of the pre-chamber incorporates a spark plug, fuelling valve, thermocouple and pressure transducer and was measured in a full engine at characteristic operating points regarding thermal efficiency, combustion process and emissions. The ignition system showed the ability to ignite highly diluted mixtures with λ = 1.6 and an efficiency gain of 14.8% compared to stoichiometric spark plug operation at 4.5 bar IMEP and 1500 rpm with a NOx emission below 100 ppm.
Schumacher, Moritz, Wensing, Michael
Vapour Space Flammability Considerations for Gasoline Compression Ignition Vehicles Operating on “Dieseline” Blends.2016-01-226610/17/2016
Gasoline Compression Ignition (GCI) has been identified as a technology which could give both high efficiency and relatively low engine-out emissions. The introduction of any new vehicle technology requires widespread availability of appropriate fuels. It would be ideal therefore if GCI vehicles were able to operate using the standard grade of gasoline that is available at the pump. However, in spite of recent progress, operation at idle and low loads still remains a formidable challenge, given the relatively low autoignition reactivity of conventional gasoline at these conditions. One conceivable solution would be to use both diesel and gasoline, either in separate tanks or blended as a single fuel (“dieseline”). However, with this latter option, a major concern for dieseline would be whether a flammable mixture could exist in the vapour space in the fuel tank. It is expected that in a practical scenario, the ambient temperature would generally exceed the Lower Flammability Limit (LFL) temperature of diesel/gasoline blends. A non-flammable vapour could still be assured, however, if the temperature in the fuel tank were above the Upper Flammability Limit (UFL) temperature. To investigate whether a flammable mixture could exist, the Upper Flammability Limit (UFL) temperatures of 12 distinct blends of gasoline, diesel, ethanol and ETBE were investigated in a special combustion chamber designed to mimic a vehicle tank, with a 5% fuel fill level to represent expected worst case conditions. The results should be considered as provisional, but suggest that under realistic assumptions of gasoline DVPE and ambient temperature, nonflammable blends can be achieved with mixtures containing a minimum of 25-40% gasoline. Derived Cetane Numbers up to 36-40 could be achieved, making the fuels suitable for Low Temperature Combustion.
Cracknell, Roger, Bardon, Michael, Gardiner, David, Pucher, Greg, Hamje, Heather, Rickeard, David, Ariztegui, Javier, Pellegrini, Leonardo
CryoFOSS Optical Sensor Offers Next-Level Liquid MeasurementTBMG-2561810/1/2016
NASA engineer Allen Parker and a team at Armstrong Flight Research Center have developed a fiber-optic-based sensing technology that accurately pinpoints and measures liquid levels. The CryoFOSS, or Cryogenic Fiber Optic Sensing System, uses fiber optic Bragg sensors, located along a single cable, to actively discern between liquid and gas states. The technology can be employed in a variety of applications, from NASA’s rockets to a winery’s storage tanks.
Advanced Heavy Truck Frame Design and Opportunities for Fuel System Impact Protection2016-01-80499/27/2016
Frame rail design advances for the heavy truck industry provide numerous opportunities for enhanced protection of fuel storage systems. One aspect of the advanced frame technology now available is the ability to vary the frame rail separation along the length of the truck, as well as the depth of the frame. In this study, the effect of incorporating the fuel storage system within advanced technology tapered frame rails was evaluated using virtual testing under impact conditions. The impact performance was evaluated under a range of horizontal impacts conditions. The performance observed was quantified and then compared with previous testing of baseline diesel tank systems. Fuel storage system impact performance metrics over the range of crash conditions considered were quantified using virtual testing methods. The results obtained from the application of the impact performance evaluation methodology were then described. The results indicated that substantial improvements in fuel storage system impact protection were available utilizing the advanced tapered frame rail technology. Opportunities available with the use of advanced frame technologies were described.
Friedman, Keith, Bui, Khanh, Hutchinson, John, Stephens, Matthew, Gonzalez, Francisco
Effect of Trapped Air on Pressure Measurements in Immersed Fuel Pipes in Aeronautical Applications2016-01-20509/20/2016
The effect of air pockets in capillaries in terms of pressure variations is investigated experimentally. Pressure sensors in aircraft are often installed separate to the pipes and connected with capillaries to minimise ignition sources within fuel tanks. Trapped air within these capillaries might distort the measurement. These effects are characterised in this paper. Extensive tests with different capillary configurations, trapped air volumes and pressure transients are studied. The data obtained shows that the main effect of trapped air during pressure transients is a delay in the pressure response against its excitation, causing local pressure oscillations around its source value until the pressure is equal in both places again. These oscillations can turn into high pressure peaks under critical conditions. Greater amounts of air can cause greater delays and viceversa. When the amount of air is such that capillary pressurisation synchronises with the maximum pressure value in the main gallery, pressure peaks can reach their highest. Conversely, when the pressure rise in the capillary occurs much before the maximum in the main gallery or when it is already descending, pressure peaks are much softer. However, if the pressure transient is not abrupt enough (>200kPa/s), pressure oscillations in the capillary are not significant, independently of the amount of air. Transient origin and trapped air volume are then the two main parameters affecting the pressure reading in the sensor installed at the end of the capillary. If both parameters align, the measured pressure peak can become extremely high.
Espinosa Sanchez, Martin, Pérez Millás, Mario
Control Solutions Synchronize Operation of Space Launch System Heavy TransportersTBMG-248886/1/2016
Control panels, embedded PCs, automation software, and servomotors and drives Beckhoff Automation Savage, MN 952-890-0000
Development of a New Pressure Measurement Technique and PIV to Validate CFD for the Aerodynamics of Full-scale Vehicles2016-01-16234/5/2016
In the early stages of aerodynamic development of commercial vehicles, the aerodynamic concept is balanced with the design concept using CFD. Since this development determines the aerodynamic potential of the vehicle, CFD with high accuracy is needed. To improve its accuracy, spatial resolution of CFD should be based on flow phenomenon. For this purpose, to compare aerodynamic force, pressure profile and velocity vector map derived from CFD with experimental data is important, but there are some difficulties to obtain pressure profile and velocity vector map for actual vehicles. At the point of pressure measurement for vehicles, installation of pressure taps to the surface of vehicle, i.e., fuel tank and battery, is a problem. A new measurement method developed in this study enables measurement of surface pressure of any desired points. Also, the flexibility of its shape and measuring point makes the installation a lot easier than the conventional pressure measurement method. In the case of velocity vector measurement, there are two main problems. The first is the measurable domain by PIV is too small for a real vehicle. To solve this, simultaneous multi-camera stereoscopic-PIV that can measure enough size for the wake flow is developed. The second problem is how to validate the flow around the underfloor. For the measurement of such flow, a small probe-type PIV system consisting of a small camera, a laser fiber and a large particle seeder has been developed. By using these validation techniques, the results of RANS and LES are accessed and discrepancies between experimental results are clarified in this paper.
Fukuchi, Yuichi, Sawada, Jun, Nakajima, Masato, Murakumo, Yutaka
An Optical Characterization of the Effect of High-Pressure Hydrodynamic Cavitation on Diesel2016-01-08414/5/2016
Most modern high-pressure common rail diesel fuel injection systems employ an internal pressure equalization system in order to support needle lift, enabling precise control of the injected fuel mass. This results in the return of a fraction of the high-pressure diesel back to the fuel tank. The diesel fuel flow occurring in the injector spill passages is expected to be a cavitating flow, which is known to promote fuel ageing. The cavitation of diesel promotes nano-particle formation through induced pyrolysis and oxidation, which may result in deposits in the vehicle fuel system. A purpose-built high-pressure cavitation flow rig has been employed to investigate the stability of unadditised crude-oil derived diesel and paraffin-blend model diesel, which were subjected to continuous hydrodynamic cavitation flow across a single-hole research diesel nozzle. Continuous in-situ spectral optical extinction (405 nm) has been employed to identify and determine variations in fuel composition as a function of the cavitation duration. The results of two high-pressure diesel cavitation experiments are reported. The first dealt with the effect of injection pressure on the rate of induced variation in chemical composition of diesel, and concluded that faster degradation of the fuel occurred at higher pressure. The second experiment involved an investigation into the variation in composition occurring in diesel fuel and the paraffin-blend model diesel, subjected to cavitating flow over a longer duration. Observed differences suggest that the high-pressure cavitation resulted in hydrodynamic sono-chemical destruction of aromatics in the diesel, which is believed to lead to carbonaceous nano-particle formation.
Lockett, Russel, Fatmi, Zeeshan, Kuti, Olawole, Price, Richard
Design Improvement on Plastic Fuel Tank System with Model Bias Prediction2016-01-02864/5/2016
With the increasing development in automotive industry, finite element (FE) analysis with model bias prediction has been used more and more widely in the fields of chassis design, body weight reduction optimization and some components development, which reduced the development cycles and enhanced analysis accuracy significantly. However, in the simulation process of plastic fuel tank system, there is few study of model validation or verification, which results that non-risky design decisions cannot be enhanced due to too much consuming time. In this study, to correct the discrepancy and uncertainty of the simulated finite element model, Bayesian inference-based method is employed, to quantify model uncertainty and evaluate the simulated results based on collected data from real mechanical tests of plastic fuel tanks and FE simulations under the same boundary conditions. The advantages and disadvantages of the applied method are presented, and the effectiveness of the proposed approach is also demonstrated. It is shown that the accuracy of FE simulations coupled with model bias prediction increases apparently.
Wang, Changsheng, Liu, Haijiang, Zhang, Tao, Zhu, Zhiyong, Liu, Liang
Investigation of Long Term Fuel Storage Influence on Taiwan Diesel Fuel (Containing 2% FAME)2016-01-12794/5/2016
Biodiesel, Fatty Acid Methyl Esters (FAME), can be made from different types of animal and vegetable oils. Its characteristics are different from those of fossil diesel, such as oxygen content, higher cold filter plugging point, and so on. Compared with fossil diesel, biodiesel can be oxidized more easily. If the fuel is oxidized, there might be product to cause some problems, like blocking filters. Therefore, the information of the storage life of the fuel is very important to vehicle owners. Moreover, the storage condition of the fuels is related to the types of source materials, additives, local weather or quality control of biodiesel. This research had used D100 and B2 fuels as experiment samples. (Blending B100 made by two different companies and represented A and B.) Three experiments including the static long storage tank test, fuel tank circulation test, and during long parking periods stability test were used to explore the influence of B2 biodiesel, diesel containing 2% of FAME, on the fuel storage under Taiwan weather and the condition of cold-start of vehicles which are not started for a long time. The results showed that under the change of fuel temperature with engine started, the speed of fuel oxidation was increased and the index of oxidation stability was not complied with the fuel standards after three months. However, if the fuel was under static condition, it had longer period of anti-oxidation. Therefore, under the environment and habit of vehicle using in Taiwan, the fuel with the engine started should not be stored in the fuel tank for more than three months and the fuel not being used should not be stored for more than six months to avoid the deterioration. Furthermore, to avoid the mild rust of the fuel tank as in the experiment or the generation of product of oxidation, it is necessary to clean the water and impurities at the bottom of the fuel tank periodically.
Lin, Ko Wei, Chen, Ya Lun, Ku, Yong-Yuan, Tang, Ta-Wei
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