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Technical Paper

CFD Investigation of the Effects of Gas’ Methane Number on the Performance of a Heavy-Duty Natural-Gas Spark-Ignition Engine

Natural gas (NG) is an alternative fuel for spark-ignition engines. In addition to its cleaner combustion, recent breakthroughs in drilling technologies increased its availability and lowered its cost. NG consists of mostly methane, but it also contains heavier hydrocarbons and inert diluents, the levels of which vary substantially with geographical source, time of the year and treatments applied during production or transportation. To investigate the effects of NG composition on engine performance and emissions, a 3D CFD model of a heavy-duty diesel engine retrofitted to NG spark ignition simulated lean-combustion engine operation at low speed and medium load conditions. The work investigated three NG blends with similar lower heating value (i.e., similar energy density) but different Methane Number (MN). The results indicated that a lower MN increased flame propagation speed and thus increased in-cylinder pressure and indicated mean effective pressure.

Prototype Powertrain in Motorsport Endurance Racing

Racing continues to be the singular, preeminent source of powertrain development for automakers worldwide. Engineering teams rely on motorsports for the latest prototype testing and research. Endurance racing provides the harshest and most illuminating stage for system design validation of any motorsport competition. While advancements throughout the 20th Century brought about dramatic increases in engine power output, the latest developments from endurance racing may be more impactful for fuel efficiency improvements. Hybrid powertrains are a critical area of research for automakers and are being tested on the toughest of scales. Prototype Powertrain in Motorsport Endurance Racing brings together ten vital SAE technical papers and SAE Automotive Engineering magazine articles surrounding the advancements of hybrid powertrains in motorsports.
Technical Paper

The Future of the Internal Combustion Engine After “Diesel-Gate”

The paper captures the recent events in relation with the Volkswagen (VW) Emissions Scandal and addresses the impact of this event on the future of power train development. The paper analyses the impact on the perspectives of the internal combustion engine, the battery based electric car and the hydrogen based technology. The operation of the United States Environmental Protection Agency (EPA), VW and the United States prosecutor, sparked by the action of the International Council on Clean Transportation (ICCT) is forcing the Original Equipment Manufacturers (OEM) towards everything but rationale immediate transition to the battery based electric mobility. This transition voids the value of any improvement of the internal combustion engine (ICE), especially in the lean burn, compression ignition (CI) technology, and of a better hybridization of powertrains, both options that have much better short term perspectives than the battery based electric car.
Technical Paper

Guidance and Range Extension Control System for a Hybrid Projectile

A Hybrid Projectile (HP) is a ballistically launched round that transforms into an Unmanned Aerial Vehicle (UAV) at a designated point during flight. Aerodynamic control surfaces and associated control laws were sought that would extend the projectile's range using body lift and include guidance for a selected point of impact. Several challenges were encountered during the modification of an existing projectile, in this case a 40mm round, to achieve range extension and controllability. The control surfaces must be designed to allow for de-spin, controllability, and natural static stability. Also, a control system with laws and guidance relationships between heading, pitch or glide rate, and the associated aerodynamic surface movements needed to be developed. The designed aerodynamic surfaces, external ballistics, and control methods developed were modeled in a projectile flight simulator built in MATLAB.
Journal Article

Roll and Pitch Produced During an Uneven Wing Deployment of a Hybrid Projectile

Uneven wing deployment of a Hybrid Projectile (HP), an Unmanned Aerial Vehicle (UAV) that is ballistically launched and then transforms, was investigated to determine the amount of roll and pitch produced during wing deployment. During testing of an HP prototype, it was noticed that sometimes the projectile began to slightly roll after the wings were deployed shortly after apogee. In this study, an analytical investigation was done to determine how the projectile body dynamics would be affected by the wings being deployed improperly. Improper and uneven wing deployment situations were investigated throughout the course of this study. The first analyzed was a single wing delaying to open. The second was if only one wing was to lock into a positive angle of incidence. The roll characteristics when both wings were deployed but only one was locked into an angle of incidence resulted in a steady state roll rate of 4.5 degrees per second.
Technical Paper

Investigation of On-Road Crosswinds on Interstate Tractor-Trailer Aerodynamic Efficiency

Heavy duty tractor-trailers under freeway operations consume about 65% of the total engine shaft energy to overcome aerodynamic drag force. Vehicles are exposed to on-road crosswinds which cause change in pressure distribution with a relative wind speed and yaw angle. The objective of this study was to analyze the drag losses as a function of on-road wind conditions, on-road vehicle position and trajectory. Using coefficient of drag (CD) data available from a study conducted at NASA Ames, Geographical Information Systems model, time-varying weather data and road data, a generic model was built to identify the yaw angles and the relative magnitude of wind speed on a given route over a given time period. A region-based analysis was conducted for a study on interstate trucking operation by employing I-79 running through West Virginia as a case study by initiating a run starting at 12am, 03/03/2012 out to 12am, 03/05/2012.
Journal Article

Finite Element Analysis of Composite Over-wrapped Pressure Vessels for Hydrogen Storage

This paper presents 3D finite element analysis performed for a composite cylindrical tank made of 6061-aluminum liner overwrapped with carbon fibers subjected to a burst internal pressure of 1610 bars. As the service pressure expected in these tanks is 700 bars, a factor of safety of 2.3 is kept the same for all designs. The optimal design configuration of such high pressure storage tanks includes an inner liner used as a gas permeation barrier, geometrically optimized domes, inlet/outlet valves with minimum stress concentrations, and directionally tailored exterior reinforcement for high strength and stiffness. Filament winding of pressure vessels made of fiber composite materials is the most efficient manufacturing method for such high pressure hydrogen storage tanks. The complexity of the filament winding process in the dome region is characterized by continually changing the fiber orientation angle and the local thickness of the wall.
Technical Paper

Comparison of Particulate Matter Emissions from Different Aftertreatment Technologies in a Wind Tunnel

Stringent emission regulations have forced drastic technological improvements in diesel after treatment systems, particularly in reducing Particulate Matter (PM) emissions. Those improvements generally regard the use of Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) and lately also the use of Selective Catalyst Reduction (SCR) systems along with improved engine control strategies for reduction of NOx emissions from these engines. Studies that have led to these technological advancements were made in controlled laboratory environment and are not representative of real world emissions from these engines or vehicles. In addition, formation and evolution of PM from these engines are extremely sensitive to overall changes in the dilution process.
Technical Paper

Innovative Dense Lightweight Design for On-Board Hydrogen Storage Tank

The hydrogen economy envisioned in the future requires safe and efficient means of storing hydrogen fuel for either use on-board vehicles, delivery on mobile transportation systems or high-volume storage in stationary systems. The main emphasis of this work is placed on the high -pressure storing of gaseous hydrogen on-board vehicles. As a result of its very low density, hydrogen gas has to be stored under very high pressure, ranging from 350 to 700 bars for current systems, in order to achieve practical levels of energy density in terms of the amount of energy that can be stored in a tank of a given volume. This paper presents 3D finite element analysis performed for a composite cylindrical tank made of 6061-aluminum liner overwrapped with carbon fibers subjected to a burst internal pressure of 1610 bars. As the service pressure expected in these tanks is 700 bars, a factor of safety of 2.3 is kept the same for all designs.
Technical Paper

Chassis Dynamometer Emissions Characterization of a Urea-SCR Transit Bus

West Virginia University characterized the emissions and fuel economy performance of a 30-foot 2010 transit bus equipped with urea selective catalytic reduction (u-SCR) exhaust aftertreatment. The bus was exercised over speed-time driving schedules representative of both urban and on-highway activity using a chassis dynamometer while the exhaust was routed to a full-scale dilution tunnel with research grade emissions analyzers. The Paris speed-time driving schedule was used to represent slow urban transit bus activity while the Cruise driving schedule was used to represent on-highway activity. Vehicle weights representative of both one-half and empty passenger loading were evaluated. Fuel economy observed during testing with the urban driving schedule was significantly lower (55%) than testing performed with the on-highway driving schedule.
Technical Paper

A Comparison of Wing Stowing Designs Focused on Increased Continuous Payload Volume for Projectile Applications

West Virginia University's Mechanical and Aerospace Engineering Department is studying the benefits of continuous payload volume in transforming projectiles. Continuous payload volume is the single largest vacancy in a vehicle that may be utilized. Currently there is a market for transforming projectiles, which are gun launched (or tube launched) vehicles stowed in an initial configuration; which deploy wings once exiting the launcher to become small unmanned aircraft. WVU's proposed design uses a helical hinge, which allows the wing sections to be externally stowed outside the UAV's fuselage. Additionally, the design positions the vehicles wing sections sub-bore (or smaller than the guns internal diameter), and flush (smooth and planer) to the surface of the fuselage. The typical transforming winged projectile design considered, stores its wing sections along the center axis of the fuselage. This bisects the payload space and limits the continuous payload carrying potential.
Journal Article

An Experimental Investigation of the Transient Effects Associated with Wing Deployment During Ballistic Flight

Mortar weapons systems have existed for more than five hundred years. Though modern tube-launched rounds are far more advanced than the cannon balls used in the 15th century, the parabolic trajectory and inability to steer the object after launch remains the same. Equipping the shell with extending aerodynamic surfaces transforms the unguided round into a maneuverable munition with increased range [1] and precision [2]. The subject of this work is the experimental analysis of transient aerodynamic behavior of a transforming tube-launched unmanned aerial vehicle (UAV) during transition from a ballistic trajectory to winged flight. Data was gathered using a series of wind tunnel experiments to determine the lift, drag, and pitching moment exerted on the prototype in various stages of wing deployment. Flight models of the design were broken down into three configurations: “round”, “transforming”, and “UAV”.
Technical Paper

Innovative Design Concepts for Lightweight Floors in Heavy Trailers

Currently, the chassis assembly contributes about 73 percent of the overall weight of a 14.63 m long haul trailer. This paper presents alternative design concepts for the structural floor of a van trailer utilizing sandwich panels with various material and geometric characteristics of the core layer in order to reduce its weight significantly below that of the current design configuration. The main objective of the new designs is to achieve optimal tradeoffs between the overall structural weight and the flexural stiffness of the floor. Various preliminary design concepts of the core designs were compared on the basis of a single section of the core structure. Six different designs were analyzed by weight, maximum displacement and maximum stress under bending and torsion loads. Each concept was kept uniform by length, thickness, loading and boundary conditions. Each design concept was examined through testing of scaled model for floor assemblies.
Technical Paper

Performance Evaluation of Metal Matrix Composites Bolted Joints

Recent advances in Metal Matrix Composites have made them ready for transition to large-volume production and commercialization. Such new materials seem to allow the fabrication of higher quality parts at less than 50 percent of the weight as compared to steel. The increasing requirements of weight savings and extended durability motivated the potential application of MMC technology into the heavy vehicle market. However, significant technical barriers such as joining are likely to hinder the broad applications of MMC materials in heavy vehicles. The focus of this paper is to examine the feasibility of manufacturing and the behavior of bolted joint connections made from aluminum matrix reinforced with Silicon Carbide (SiC) particles. Two reinforcement ratios: 20% and 45% were considered in this study. The first part of the paper concentrates on experimental evaluation of bolted MMC joints.
Technical Paper

Methods to Assess Jolting and Jarring Events: A Surface Mining Case Study to Evaluate the Jolt-Duration Method

When operating a piece of heavy equipment, the equipment operator is exposed to Whole Body Vibration (WBV), with peaks in the acceleration called jolting and jarring. Various published consensus standards exist to analyze overall WBV, but a consensus standard does not exist for describing, detecting, and categorizing the jolting and jarring peaks. During previous research into methods of measuring jolting and jarring, a Root Mean Square (RMS) method was implemented and deployed in jolting and jarring event meters called Shox Boxes (invented by the National Institute for Occupational Safety and Health, NIOSH). The RMS assessment was difficult for end users of the Shox Boxes to utilize for describing and categorizing the peaks. This paper offers a hypothetical standard, the Jolt-Duration (JD) method, based on the simple amplitude and duration of the peaks, as well as the time between peaks.
Technical Paper

Finite Element Analysis for the Interface of a Respirator and the Human Face -A Pilot Study

Comfort assessment of respirator fit plays an important role in the respirator design process and standard development. To reduce the cost and design time of respirators, the design, fit, and evaluation process can be performed in a virtual environment. Literature shows that respirator-induced discomfort relates to stress, area, and region of the face covered. In this work, we investigate the relationship between the strap tensions and the stress and deformation distribution on the interface between the respirator and the headform. This is the first step towards a comprehensive understanding of the contribution of contact stress to the mathematical comfort fit model. The 3D digital models for respirators and headforms have been developed based on 3D scanning point-cloud using a Cyberware® 3D digitizer. Five digital headform models have been generated: small, medium, large, long and short.
Technical Paper

A New Approach to Developing Digital 3-D Headforms

Facial measurements were collected during the 2003 National Institute for Occupational Safety and Health (NIOSH) survey of 3,997 respirator users. In addition to traditional measuring techniques, 1013 subjects were scanned with a Cyberware 3-D Rapid Digitizer. Ten facial dimensions relevant to respirator fit were chosen for defining a principal component analysis (PCA) model which divides the user population into five face-size categories. Mean facial dimensions were then computed as a goal for a representative headform for each size category and used to identify 5 scans in each category. An average of the five scanned subjects was used to develop a single standard headform for each face-size category. Four digital 3-D models were developed: small, medium, large, and long. The new headforms include facial features not found on current standard headforms.
Technical Paper

Digital Human Modeling Goals and Strategic Plans

Digital human modeling (DHM) progress worldwide will be much faster and cohesive if the diverse community now developing simulations has a global blueprint for DHM, and is able to work together efficiently. DHM developers and users can save time by building on each other's work. This paper highlights a panel discussion on DHM goals and strategic plans for the next decade to begin formulating the international blueprint. Four subjects are chosen as the starting points: (1) moving DHM into the public safety and internet arenas, (2) role of DHM in computer assisted surgery and automotive safety, (3) DHM in defense applications, and (4) DHM to improve workplace ergonomics.
Technical Paper

Development and Testing of a Tag-based Backup Warning System for Construction Equipment

Incidents in which a piece of construction equipment backed into a worker resulted in an average of 17 deaths per year at road construction sites and 15 deaths per year at building construction sites from 1997 through 2001. This trend continues and researchers at the National Institute for Occupational Safety and Health are evaluating methods to decrease these incidents. A new technology based on the detection of electronic identification tags worn by workers has been developed and evaluated at a road construction site. The tag-based proximity warning system consists of a magnetic field generator and communications system that mounts on the back of a piece of construction equipment such as a dump truck, road grader, or loader. Workers at a construction site wear a small tag that detects the magnetic marker field.
Technical Paper

A Comparison of Crash Patterns in Heavy Trucks with and Without Collision Warning System Technology

Collision warning systems (CWS) are a relatively new technology to reduce or mitigate motor vehicle rear-end and side impact collisions. This study compared available police-reported crash experiences of 6,143 CWS-equipped heavy trucks with the experiences of 383,058 heavy trucks without CWS. Data were from the Motor Carrier Management Information System (2000-2002). Results suggest that CWS-equipped trucks had a significantly lower proportion of crashes involving other moving vehicles and a significantly lower proportion of multiple vehicle crashes compared to trucks without CWS, (40% vs. 49%, p<0.0001; 62% vs. 67%, p<0.004 respectively). These changes are the first crash-data based evidence that supports the design effect of CWS. However, more studies are needed to determine the specific impacts of CWS on heavy truck crashes.