bluuebunny/crossref_metadata_2025 huggingface dataset:
Waste Heat Recovery in Heavy-Duty Diesel Engines: A Thermodynamic Analysis of Waste Heat Availability for Implementation of Energy Recovery Systems Based Upon the Organic Rankine Cycle
Authors: Cozzolini A. , Besch M. C. , Littera D. , Kappanna H. , Bonsack P. , Gautam M. , Cordiner S. , Mulone V.
Published: July 2013

In the past decade automotive industries have focused on the development of new technologies to improve the overall engine efficiency and lower emissions in order to satisfy the always more stringent emission standards introduced all around the world. Technical progress has primarily focused on two aspects; the optimization of the air-fuel mixture in the combustion chamber as well as the combustion process itself, leading to simultaneous improvements in both, efficiency (lowering fuel consumption for same power output) and emissions levels which ultimately result from the optimized combustion process. Although engine technology has made significant progress, even modern Diesel combustion engines do not exceed a maximum efficiency of approximately 40%. Hence, around 60% of the available energy carried by the fuel and entering the combustion chamber is dissipated as heat to the environment. The next steps in engine optimization will see the integration of waste heat recovery systems (WHRS) to increase the overall energy efficiency of the propulsion system by means of recovering parts of the waste heat generated during normal engine operation. The presented was aimed at analyzing the availability as well as the quality of heat to be used in WHRS for the case of heavy-duty Diesel (HDD) engines employed in Class-8 tractors, which are suitable candidates for optimization via WHRS implementation as their engines spend most of their time operating at quasi steady state conditions, such as highway cruise. Three different primary energy sources have been considered: exhaust gas recirculation (EGR) cooling system, engine cooling system and exhaust gas stream. Experimental data has been gathered at West Virginia University’s Engine and Emissions Research Laboratory (EERL) facility in order to quantify individual heat flows in a model year (MY) 2004 Mack® MP7-355E HDD engine operated over the 13 modes of the European Stationary Cycle (ESC). Analysis based on second law efficiency underlined that not the whole amount of waste heat can be successfully used for recovery purposes and that heat sources which offer a large amount of waste energy reveal to be inappropriate for recovery purposes in case of low operating temperature. Time integral analysis revealed that engine modes which appear to offer high recovery potential in terms of waste power may not be suitable engine operating conditions when the analysis is performed in terms of waste energy, depending on the particular engine cycle. Finally a simple thermodynamic model of a micro power unit running on an Organic Rankine Cycle (ORC) has been used to assess the theoretical improvement in engine efficiency during steady state operations based on a second law efficiency analysis approach.
PR30C-LE Locomotive With DOC and Urea Based SCR: Baseline and Initial Aftertreatment Emissions Testing
Authors: Osborne Dustin T. , Biagini Doug , Holmes Harold , Fritz Steven G. , Jaczola Michael , Iden Michael E.
Published: July 2013

The PR30C-LE is a repowered six-axle, 2,240 kW (3,005 hp), line-haul locomotive that was introduced to the rail industry in 2009. The Caterpillar 3516C-HD Tier 2 engine is equipped with an exhaust aftertreatment module containing selective catalyst reduction (SCR) and diesel oxidation catalyst (DOC) technology. PR30C-LE exhaust emission testing was performed on test locomotive PRLX3004. Phase-1 of the test program included the following tasks: engine-out baseline emissions testing without the aftertreatment module installed, aftertreatment module installation, commissioning and degreening, and emissions testing with the aftertreatment. Emission results from testing without the aftertreatment module, referred to as the baseline configuration, indicated that PRLX3004 emissions were below Tier 2 EPA locomotive limits without aftertreatment. Emission test results with the DOC and SCR aftertreatment module showed a reduction in nitrogen oxides (NOx) of 80 percent over the line-haul cycle, and 59 percent over the switcher cycle. Particulate matter (PM) was reduced by 43 percent over the line-haul cycle and 64 percent over the switcher cycle. Line-haul cycle composite emissions of Hydrocarbon (HC) and carbon monoxide (CO) were reduced by 93 and 72 percent, respectively. The PR30C-LE locomotive achieved Tier 4 line-haul NOx, CO, HC, as well as Tier 3 PM levels. There are currently five PR30C-LE locomotives in operation in California and Arizona, and the total hour accumulation of the five PR30C-LE locomotives as of October 2011 was 20,000 hours.
Comparative Study of Diesel Oil and Biodiesel Spray Combustion Based on Detailed Chemical Mechanisms
Authors: Yang Junfeng , Golovitchev Valeri I. , Naik Chitralkumar V. , Meeks Ellen
Published: July 2013

A master combustion mechanism of biodiesel fuels has recently been developed by Westbrook and co-workers [1]. This detailed mechanism involves 5037 species and 19990 reactions, the size, which prohibits its direct use in computational fluid dynamic (CFD) applications. In the present work, various mechanism reduction methods included in the Reaction Workbench software [2] were used to derive a semi-detailed reduced combustion mechanism maintaining the accuracy of the master mechanism for a desired set of engine conditions. The reduced combustion mechanism for a five-component biodiesel fuel was implemented in the FORTÉ CFD simulation package [3] to take advantage of advanced chemistry solver methodologies and advanced spray models. The spray characteristics, e.g. the liquid penetration and flame lift-off distances of RME fuel were modeled in a constant-volume combustion chamber. The modeling results were compared with the experimental data. Engine simulations were performed for the Volvo D12C heavy-duty diesel engine fueled by RME on a 72° sector mesh. Predictions were validated against measured in-cylinder parameters and exhaust emission concentrations. The semi-detailed mechanism was shown to be an efficient and accurate representation of actual biodiesel combustion and emissions formation. Meanwhile, as a comparative study, the simulation based on a detailed diesel oil surrogate mechanism were performed for diesel oil under the same conditions.
Operating History Artifacts of Large Engine Particulate Matter Emissions Measurement
Authors: Vojtisek-Lom Michal , Jirků Jonáš
Published: July 2013

Exhaust emissions from internal combustion engines are one of the leading sources of fine particulate matter emissions in urban areas. Off-road engines account for a substantial portion of the total emissions, and are subject to increasingly strict legislation as well as voluntary emissions reduction programs. The benefits of various emissions reduction programs are typically quantified with simplified, short duration field tests. In an inquiry into the suitability of such tests, this paper examines experimental data collected by portable, on-board monitoring systems on truck, tractor, construction equipment, marine and locomotive diesel engines with rated power ranging from 130 to 1550 hp and displacement ranging from 4 to 163 liters. In engines operated extensively at low load, such as some locomotive engines, substantial amounts of solids and liquids accumulate inside of the engine and in the exhaust system. These deposits are then driven off during subsequent operation at high load. As a result, the emissions of particulate matter may be elevated for a rather long time, on the order of tens of minutes, which is longer than the duration of the individual modes of most field emissions tests. Therefore, the emissions of fine particles measured during short (units of minutes per mode) tests may be affected by the accumulated deposits. If this phenomenon is overlooked and not properly accounted for, the measurements may be less repeatable or comparable, and the particulate matter emissions based on such measurements may be overestimated. On the other hand, it is not clear that the problem can be remedied if the engine is diligently preconditioned prior to the measurement — in this case, the measured values do not account for “excess” emissions associated with extended low-load operation.
Investigating the Use of Heavy Alcohols as a Fuel Blending Agent for Compression Ignition Engine Applications
Authors: Ramírez Anita I. , Som Sibendu , LaRocco Lisa A. , Rutter Timothy P. , Longman Douglas E.
Published: July 2013

There has been an extensive worldwide search for alternate fuels that fit with the existing infrastructure and would thus displace fossil-based resources. In metabolic engineering work at Argonne National Laboratory, strains of fuel have been designed that can be produced in large quantities by photosynthetic bacteria, eventually producing a heavy alcohol called phytol (C20H40O). Phytol’s physical and chemical properties (cetane number, heat of combustion, heat of vaporization, density, surface tension, vapor pressure, etc.) correspond in magnitude to those of diesel fuel, suggesting that phytol might be a good blending agent in compression ignition (CI) engine applications. The main reason for this study was to investigate the feasibility of using phytol as a blending agent with diesel; this was done by comparing the performance and emission characteristics of different blends of phytol (5%, 10%, 20% by volume) with diesel. The experimental research was performed on a single-cylinder engine under conventional operating conditions. Since phytol’s viscosity is much higher than that of diesel, higher-injection-pressure cases were investigated to ensure the delivery of fuel into the combustion chamber was sufficient. The influence of the fuel’s chemical composition on performance and emission characteristics was captured by doing an injection timing sweep. Combustion characteristics as shown in the cylinder pressure trace were comparable for the diesel and all the blends of phytol at each of the injection timings. The 5% and 10% blends show lower CO and similar NOx values. However, the 20% blend shows higher NOx and CO emissions, indicating that the chemical and physical properties have been altered substantially at this higher percentage. The combustion event was depicted by performing high-speed natural luminosity imaging using endoscopy. This revealed that the higher in-cylinder temperatures for the 20% blend are the cause for its higher NOx emissions. In addition, three-dimensional simulations of transient, turbulent nozzle flow were performed to compare the injection and cavitation characteristics of phytol and its blends. Specifically, area and discharge coefficients and mass flow rates of diesel and phytol blends were compared under corresponding engine operating conditions. The conclusion is that phytol may be a suitable blending agent with diesel fuel for CI applications.
Analysis of Cyclic Combustion Variability in Gasoline Engines
Authors: Chappell Edward , Brace Chris , Tily Roger
Published: July 2013

The research described in this paper was aimed at determining any common precedents for abnormal combustion events in a gasoline engine in order that their occurrence might be predicted and ultimately corrected.

Combustion data was collected for 1200 cycles from a motorbike spark ignition engine running at 4,000rpm and 1.15 bar BMEP at fuelling conditions ranging from rich through stoichiometric to lean. The least cyclic variability occurred during slightly rich fuelling and was best characterised through the heat released per cycle.

Phase-lag plots of the heat released per cycle showed boomerang shaped patterns, indicating deterministic cyclic variability. This suggested that an algorithm capable of predicting poor cycles could be developed. It was found, however, that the majority of poor combustion events are preceded by cycles of an approximately average heat release and that poor combustion events are likely to be followed by a strong combustion event. Importantly not all poor cycles follow this pattern. This means that existing prediction algorithms which are based on preceding cycles would not be suitable in this case. An examination of the chain length of good or average combustion events between poor events did not show any chain length commonality across the AFR’s.

The findings of this paper support the view that the deterministic patterns in the cyclic variations in combustion are present but that they are complex and cannot be predicted using simple metrics based on neighbouring cycles. A more thorough understanding of the fundamental contribution of previous combustion cycles to the variability is required for predictive tools to be effective.
Investigation on the Impact of Fuel Properties on Partially Premixed Combustion Characteristics in a Light Duty Diesel Engine
Authors: Solaka Hadeel , Tunér Martin , Johansson Bengt
Published: July 2013

The impact of fuel composition on the emission performance and combustion characteristics for partially premixed combustion (PPC) were examined for four fuels in the gasoline boiling range together with Swedish diesel MK1. Experiments were carried out at 8 bar IMEPg and 1500 rpm with 53±1% EGR and λ = 1.5. This relation gave inlet mole fractions of approximately 5% CO2 and 13% O2. The combustion phasing was adjusted by means of start of injection (SOI), for all fuels, over the range with stable combustion and acceptable pressure rise rate combined with maintained λ, EGR ratio, inlet pressure, and load. The operating range was limited by combustion instability for the high RON fuels, while MK1 and the low RON fuels could be operated over the whole MBT plateau. The largest difference in engine-out emissions between the fuels was the filtered smoke number (FSN), as the gasoline fuels produced a much lower FSN value than MK1. Higher RON value gave higher levels of carbon monoxide (CO) and unburned hydrocarbon (HC) for the gasoline fuels, while MK1 had the lowest levels of these emissions.
Analysis of the EGR System Performance in Modern Diesel Engines
Authors: d’Ambrosio Stefano , Ferrari Alessandro , Spessa Ezio
Published: July 2013

Exhaust Gas Recirculation (EGR) is extensively employed in diesel combustion engines to achieve NOx emission targets. The EGR is often cooled in order to increase the effectiveness of the strategy, even though this leads to a further undesired impact on PM and HC.

Experimental tests were carried out on a diesel engine at a dynamometer rig under steady-state speed and load working conditions that were considered relevant for the New European Driving Cycle. Two different shell and tube-type EGR coolers were compared, in terms of the pressure and temperature of the exhaust and intake lines, to evaluate thermal effectiveness and induced pumping losses. All the relevant engine parameters were acquired along EGR trade-off curves, in order to perform a detailed comparison of the two coolers. The effect of intake throttling operation on increasing the EGR ratio was also investigated. A purposely designed aging procedure was run in order to characterize the deterioration of the thermal effectiveness and verify whether clogging of the EGR cooler occurred.

The EGR mass flow-rate dependence on the pressure and temperature upstream of the turbine as well as the pressure downstream of the EGR control valve was modeled by means of the expression for convergent nozzles. The restricted flow-area at the valve-seat passage and the discharge coefficient were accurately determined as functions of the valve lift.
Impact of Refinery Stream Gasoline Property Variation on Load Sensitivity of the HCCI Combustion
Authors: Lacey Joshua S. , Sathasivam Sakthish R. , Filipi Zoran S. , Peyla Richard J. , Cannella William J. , Fuentes-Afflick Peter A.
Published: July 2013

The HCCI combustion process is highly reliant upon a favorable in-cylinder thermal environment in an engine, for a given fuel. Commercial fuels can differ considerably in composition and auto-ignition chemistry, hence strategies intended to bring HCCI to market must account for this fuel variability.

To this end, a test matrix consisting of eight gasoline fuels comprised of blends made solely from refinery streams were run in an experimental, single cylinder HCCI engine. All fuels contained 10% ethanol by volume and were representative of a cross-section of fuels one would expect to find at gasoline pumps across the United States. The properties of the fuels were varied according to research octane number (RON), sensitivity (S=RON-MON) and volumetric content of aromatics and olefins.

For each fuel, a sweep of load (mass of fuel injected per cycle) was conducted and the intake air temperature was adjusted in order to keep the crank angle of the 50% mass fraction burned point (CA50) constant. By analyzing the amount of temperature compensation required to maintain constant combustion phasing, it was possible to determine the sensitivity of HCCI to changes in load for various fuels.

In addition, the deviation of fuel properties brought about variations in important engine performance metrics like specific fuel consumption. Though the injected energy content per cycle was matched at the baseline point across the test fuel matrix, thermodynamic differences resulted in a spread of specific fuel consumption for the fuels tested.
Multi-Cycle Simulation of the Mixture Formation Process of an High Performance Engine at Part Load Condition
Authors: Forte Claudio , Bianchi Gian Marco , Corti Enrico , Fantoni Stefano
Published: July 2013

Transient operation of engines leads to air fuel (A/F) ratio excursions, which can increase engine emissions. These excursions have been attributed to the formation of fuel films in the intake port, which are caused by a portion of the intake fuel impinging and adhering on the relatively cool port surface. These films act as a source or sink which cause the AF variations depending upon the transient condition. Gaining a fundamental understanding of the nature and quantity of such films may assist in future fuel mixture preparation designs that could aid in emission reductions, yet would not require overly expensive nor complicated systems.

The control of air to fuel ratio is a critical issue for high performance engines: due to the low stroke-to-bore ratio the maximum power is reached at very high regimes, letting little time to the fuel to evaporate and mix with air. The injector located upstream the throttle causes a lot of fuel to impinge the throttle and intake duct walls, slowing the dynamics of mixture formation in part load conditions.

The aim of this work is to present a CFD methodology for the evaluation of mixture formation dynamics applied to a Ducati high performance engine under part load conditions.

The phenomena involved in the process are highly heterogeneous, and particular care must be taken to the choice of CFD models and their validation. In the present work all the main models involved in the simulations are validated against experimental tests available in the literature, selected based on the similarity of physical conditions of those of the engine configuration under analysis.

The multi-cycle simulation methodology here presented reveals to be a useful tool for the evaluation of the mixture dynamics and for the evaluation of injection wall film compensator models.
The Impact of Swirl Ratio and Injection Pressure on Fuel-Air Mixing in a Light-Duty Diesel Engine
Authors: Sahoo Dipankar , Petersen Benjamin R. , Miles Paul C.
Published: July 2013

Toluene fuel-tracer laser-induced fluorescence is employed to quantitatively measure the equivalence ratio distributions in the cylinder of a light-duty diesel engine operating in a low-temperature, high-EGR, and early-injection operating mode. Measurements are made in a non-combusting environment at crank angles capturing the mixture preparation period: from the start-of-injection through the onset of high-temperature heat release. Three horizontal planes are considered: within the clearance volume, the bowl rim region, and the lower bowl. Swirl ratio and injection pressure are varied independently, and the impact of these parameters on the mixture distribution is correlated to the heat release rate and the engine-out emissions.

As the swirl ratio or injection pressure is increased, the amount of over-lean mixture in the upper central region of the combustion chamber, in the bowl rim region and above, also increases. Unexpectedly, increased injection pressure results in a greater quantity of over-rich mixture within the squish volume.
Lateral Creepage
Authors: Hasan Nazmul
Published: July 2013

This is a theoretical work on lateral creepage, εy for both tangent and curved track. From the equation of motion on tangent track, the expression for the maximum lateral velocity is obtained and then followed by the basic definition of lateral creepage to obtain the maximum lateral creepage. For tangent track the maximum lateral creepage is given by: εy=y0RK in which,

y 0 is wheel clearance, γ is conicity, r is nominal wheel radius, s is the track width, RK is the Klingel radius.

Lateral creepage for a curve is expressed by replacing the Klingel radius with the radius of curve, R as shown below: εy=y0R

A lateral slip in the running surface exists because of the wheel’s attack angle, which causes the flange to push against the inside of the railhead; consequently, a lateral slip force will be developed [1]. Clearly, this situation provides valid grounds to find a correlation between lateral creepage and the angle of attack. Exactly this is given below.

For curved track: εy=0.069B2R+0.2862y0B in which,

B is wheel base, R is radius of curve.

This equation is suggested for the lateral creepage on the curve, as it contains both components of the angle of attack that connects all important parameters, such as radius, wheel base and wheel clearance.

A threshold creepage value of 0.0045 is suggested. It is shown that a curve with a radius greater than 300 m should not produce wheel squeal noise.
An Experimental Study About the Effects of High Speed Rail’s Construction and Operation on the Ability of These Involving Enterprises
Authors: Yin Jing , Li Xuemei , Guo Zhuxue
Published: July 2013

Since High-Speed Rail (HSR) began planned and constructed, many involving enterprises obtain interests from the process. But with increasing number of High-Speed railways being planned, constructed, and then operated, it will inevitably bring more improvement on the ability of these involving enterprises. So, no matter policy planers and the entrepreneurs or investors, understand the inner mechanism of the mutual influence between the development of High-Speed Rail and the improvement of involving enterprises is a key point to keep harmonious and efficient development of infrastructure construction simultaneously with the enterprises. In this paper, it is presented an example of an experimental study investigating the effects of high speed rail’s construction and operation on these involving enterprises in each link of this high speed rail industry chain.

As we know, social division of labor improves the efficiency of society, and with more detailed-oriented division, more enterprises and experts are engaged in one or several domains. Thus the construction and operation of high speed way are complex processes completed by numerous enterprises, each one or some of which only need to deal with one part. By sorting the industry chain of high speed rail, 50 listed enterprises are selected with their operated data from 2006 to 2010. The comprehensive evaluation system of enterprises ability is modeled by factor analysis method to obtain the key factors, which affect the development of enterprises. The results show the ability of these enterprises are influenced by their scale, profitability, debt, operation ability and progressive ability, and the enterprises in different link own their special abilities compared with those of other links.

And next, from the time dimension, the abilities of enterprises have been changed from 2006 to 2010, especially one or several abilities that summarized in the previous part. So via variance analysis, the change laws of ability are explored in the process of construction and operation of high speed rail, which, on one hand, is confirmed the promotion of high speed rails to these abilities of enterprises, on the other hand, shows the inner mechanism and rules in the process.
Fracture Mechanics and Beam Theory Analyses of Semi-Elliptical Cracks Originating in the Base of Rail
Authors: Jeong David Y. , Carolan Michael E. , Yu Hailing , Perlman Benjamin , Gordon Jeffrey E.
Published: July 2013

In May 2011, a derailment of a passenger train occurred in a tunnel in the northeast region of the United States. Fortunately, no serious injuries or fatalities resulted from this derailment. The probable cause of the derailment was determined to be a broken rail from a defect originating in the base of the rail. This internal rail base defect is characterized as having a crescent, thumbnail, or semi-elliptical shape. In addition, the formation and growth of this defect may have been exacerbated by corrosion.

This paper describes engineering calculations to estimate the growth rate of this type of rail base defect. These engineering calculations are based on applying the principles of fracture mechanics and beam theory. Fracture mechanics principles are applied to determine stress intensity factors for the semi-elliptical shaped defect with different aspect ratios. Stress intensity factors are then used to estimate the growth of the defect under the accumulation of tonnage from repeated wheel passages. For this purpose, the rail is assumed to behave as a beam in bending.
Automated Train Brake Effectiveness (ATBE) Test Process at Canadian Pacific
Authors: Aronian Abe , Jamieson Michelle , Wachs Kim
Published: July 2013

In 2011, Canadian Pacific (CP) implemented a new Automated Train Brake Effectiveness (ATBE) process for coal trains which replaces the visual Class 1 (No.1) Air Brake test required under Canada’s Department of Transport (Transport Canada – TC) regulations. The ATBE process relies on Wayside Detector technology to assess the operation of brakes on each railcar under dynamic conditions.

CP began analyzing wayside detector information in 2008 as the basis for evaluating the braking performance of coal trains in Canadian Export service, specifically targeting existing Hot Box / Hot Wheel Detectors strategically situated alongside the track. Using the wayside detector output, the new ATBE process improves upon the visual No.1 Brake Test by evaluating brake effectiveness. The wayside detector information is automatically transmitted to a central Equipment Health Monitoring System after each train passing, where train brake effectiveness is evaluated and results published to mechanical maintenance facilities and train crews. The published results constitute the completed ATBE Test for the train.

Given the substantial number of mechanical components requiring visual inspection each day by railway train inspectors, and taking into account the considerable investment CP has made into Wayside Detection technology, focus has moved towards Technology Driven Train Inspections (TDTI), preferring predictive, proactive maintenance practices and condition-based maintenance policies instead of the traditional reactive maintenance approach.
Testing and Validation of Long Trains Under High Flow and Gradient Conditions
Authors: Aronian Abe , Wachs Kim , Jamieson Michelle , Carriere Karen , Gaughan Edward W.
Published: July 2013

The need to extend train lengths has been a primary business target of the railway industry, due to its obvious benefits. However, winter train operating conditions, excessive in-train slack action, deterioration of air brake signal propagation and the added stress on infrastructure and equipment has naturally kept the average train lengths at bay. The introduction of advanced equipment, new concepts and strategies have now enabled Canadian Pacific to change this mindset. Long Train make up is now very possible, taking into account the Distributed Power configuration. Making a very long train resemble a series of short trains coupled together, each with its own locomotives, synchronously connected to the Lead unit’s commands, makes such trains very safe and efficient. Extensive Field Testing and Train Simulation work done over the last two years at CP has shown that with the use of Multiple Remote Locomotive set-up, it is in fact very possible to safely contemplate extending the limits of today’s maximum allowed 60 CFM of total train air flow, into uncharted territory, possibly approaching a total of 90 CFM. CP has pursued to implement on a permanent basis, operating instructions that would permit Multiple Distributed Power trains to depart from a train brake test location with combined air flow of up to 90 CFM, provided the flow at each DP locomotive consist is not greater than 60 CFM and train length sections between locomotives are not exceeded. This paper investigates the operation of Distributed Power trains at higher levels of air flow and, through detail field testing and evaluation techniques, substantiates the validity of extending the safety limits of train leakage and gradient for such trains.
Toward a Common Platform for Simulation-Based Evaluation of Both Functional and Telecommunication Sub-Systems of the ERTMS
Authors: Sondi Patrick , Kassab Mohamed , Aguado Marina , Lemaire Etienne , Berbineau Marion
Published: July 2013

The deployment of the European Rail Traffic Management System (ERTMS) in Europe will be mandatory on the major corridors, but this process will be long and expensive. Industry needs faster roll-out and a reduction in cost in order to obtain the certification and authorization to put equipment into service. New lab-testing tools for European Train Control System (ETCS) validation based on automatic testing could accelerate the process. In this work, we propose a co-simulation platform relaying on two existing tools: the ERTMS simulator that implements only the functional sub-system (ETCS) of ERTMS; and the OPNET simulator that allows modeling the whole telecommunication subsystem (GSM-R) from the Physical layer to higher layers, including the Euroradio interface. We describe a co-simulation protocol that determines how the results obtained from each simulator are reused as input in the other in order to take into account the impact of the functioning of one subsystem on the other. In this way, the problems related to radio propagation impairments, network load and electromagnetic interferences can be taken into account in ERTMS evaluation. Furthermore, some actors of the railway industry think about moving towards emerging technologies like LTE (4G Long Term Evolution). This platform will also allow evaluation of prospective technologies in the framework of ERTMS scenarios before costly real-world implementation.
Assessment of a Diesel Vapor Reclamation System for Use in Diesel Electric Locomotives
Authors: Parida Basant K. , Zaouk Abdullatif K. , Punwani John , Maryott Dana
Published: July 2013

Diesel fuel used in locomotives generally does not pose a fire hazard. However, diesel vapor generated within tank vapor space attains flammability condition as the fuel temperature gets closer to the fuel-flash point, which may cause a fire hazard in the event of a tank breach due to collision or derailment of the locomotive. As a part of an ongoing Federal Railroad Administration (FRA) sponsored research effort, a proof-of-concept laboratory scale demonstration has shown that it is possible to circulate the mixture of diesel vapor and air through a small vapor condenser unit to reclaim the fuel vapor. The recovered fuel is shown to possess almost similar specific heat value and hydrocarbon constituents as that of neat diesel fuel and hence reusable. Furthermore, the vapor reclamation process enables mitigation of fire hazard and reduction of diesel vapor escape to the environment. In order to assess the real potential of diesel vapor reclamation on a running locomotive, real-time fuel temperature data was collected during a medium-haul run of a BNSF Railway freight locomotive.

This paper presents the real-time fuel temperature data collected on a BNSF Railway instrumented locomotive tank as well as results of computational fluid dynamics (CFD) analyses performed for the full-scale locomotive tank. In continuation of the research and development effort, the design of a scaled up diesel vapor reclamation system is presented. The scope of its integration with a railroad freight locomotive is summarized and subsequent steps for its performance evaluation on a running locomotive are discussed.
Improving Safety and Security Management Programs to Realize Successful Outcomes by Focusing on Requirements Management
Authors: Stokes Timothy , Cox Sue
Published: July 2013

A vital aspect of safety and security management during the development of new rail and transit projects is ensuring that safety and security requirements are properly developed and incorporated into the work products in a planned, systematic and traceable manner. The completed rail or transit project will need to operate as a fully integrated system, but it will likely be designed, supplied, constructed and tested by many parties organized through multiple contracts. Each contracted entity has a responsibility to do some aspect of the work, and can have an impact on the safety and security of the completed rail or transit project. In addition, other impacts to safety and security can arise from system interfaces and inter-modal systems, from other rail and bus systems servicing the corridor/region to highways, bike, pedestrian walkways and para-transit.

This paper discusses the critical role of safety and security requirements management during the development and delivery of rail or transit projects to ensure that safety and security is inherent in the project, consistent with US DOT regulations. Safety and security requirements management should be an integrated part of project management, rather than an after-thought at the end of the project. Requirements are not prescribed solutions; rather they are explicit statements, categorized into a logical framework, describing the functions, behaviors and qualities to be achieved. Requirements are typically specified by the owner to express what a new rail or transit project needs to accomplish from an operations perspective. Amongst the project requirements are the safety and security requirements that must be satisfied. The designer proposes a solution to satisfy the requirements, taking into account risk, cost, schedule, and other constraints such as technical issues and human factors.

By using the techniques of requirements management, owners of rail and transit properties will have visibility into the status of safety and security throughout project implementation to facilitate control over the project to realize successful outcomes. It should be noted that requirements management techniques are also applicable during the operations and maintenance, retrofit and disposal phases of a rail or transit project. Managing safety and security requirements including the verification process in a planned, systematic and documented manner confirms to the owner, operators, oversight agencies and the general public that safety and security risks have been appropriately taken into account. Thus the owner can ultimately state with confidence that the completed system is safe for operations and public use.
Feasibility of a Variable-Directivity Locomotive Horn
Authors: Ross Jason C. , Parida Basant K. , Zaouk Abdullatif K. , Nash Grant S. , Punwani Swamidas K. (John)
Published: July 2013

It is estimated that up to 9.3 million persons may be impacted by locomotive horn noise and up to 4.6 million of those may be severely impacted.1 In 2009, there were over 1,900 incidents, over 700 injuries and over 240 fatalities at highway-rail grade crossings.2 The National Academy of Engineering Committee on Technology for a Quieter America has indicated that the public would benefit if train warning horns were more directional and has recommended that research and development be undertaken to better understand the effects on safety and benefits to the public.3 A directive train horn has the potential to focus audible warning signals to desired locations including pedestrians and motorists at highway-rail grade crossings while minimizing noise to the surrounding community and employees in the locomotive cab.

As a part of an ongoing Federal Railroad Administration (FRA)-sponsored research and development effort, the authors have examined the feasibility of and recommended an acoustical specification for an optimized train horn that would improve the detectability of the warning signal for motorists at critical positions along the crossing road while reducing the area of environmental noise impact. The detectability, noise impact area and occupational noise exposure have been compared for the optimized horn and several typical standard horns.

Near the beginning of most sounding events (1/4-mile from the grade crossing) the optimized horn reduces noise exposure because a narrow beam of sound can be generated and focused at the grade-crossing. As the train approaches the crossing, the beam width must become wider. It is found that detectability could be improved and noise impact area reduced by up to 57%, but the optimized horn must have a directivity pattern and amplitude that dynamically changes as a function of train position relative to the crossing.

Current acoustic source technologies which generate directive sound were examined including “acoustic hailing devices” (AHDs) which are recent technological advancements typically used for naval communications. Capable of focusing high amplitudes of sound within a narrow beam and dynamically changing the directivity pattern through electronic beam steering, AHDs have been identified as a feasible means of meeting the required specifications. A critical design issue for the optimized horn is controlling the directivity pattern at low frequencies. Development and testing of a prototype is in progress and actual improvements to detectability and reductions in noise impact will be analyzed. The paper briefly discusses the feasibility of the optimized horn and general information on cost and implementation.
Preservation and Reuse of Abandoned Rail Corridors: Legal and Policy Issues
Authors: Morgan Curtis A. , Loftus-Otway Lisa , Hutson Nathan M. , Warner Jeffery E.
Published: July 2013

The paralleling of existing rail lines in excess right-of-way (R/W) and/or the re-use of corridors first used by railroad companies has long been a method for acquiring linear corridors for other transportation uses. The practice of re-using rail alignments is a logical one given that railroads steered development patterns in the United States prior to the highway era and the corridors that served the railroads also effectively serve existing population centers. The long period of railroad consolidation since the end of World War II resulted in the abandonment and loss of many rail corridors that would now have been extremely valuable for transportation development. Preserving former rail corridors is beneficial to transportation planners at the local and state level, as they can be employed for new transportation uses or multiuse recreational trails.

This paper discusses the findings of a multifaceted research project that examined issues associated with acquisition, preservation, and re-use of abandoned rail corridors in Texas. The paper summarizes the legal and policy review that analyzed Texas, Federal, and other state abandonment policies to determine what, if any, changes would be necessary for the Texas Department of Transportation (TxDOT) to take advantage of future opportunities to acquire and preserve these corridors. The paper also reviews results that identified and documented past Texas rail abandonments and identification of potential uses for existing/prospective abandoned corridors. The paper concludes with an overview of the findings of this study which noted that as the state’s population continues to grow, preserving all potential transportation corridors for rail or alternative uses will grow in importance.
Passenger Boarding/Alighting Management in Urban Rail Transportation
Authors: Baee Sonia , Eshghi Farshad , Hashemi S. Mehdi , Moienfar Rayehe
Published: July 2013

Heavy traffic consequences in crowded cities can be extremely reduced by using mass transportation. Recent extensive studies on Tehran subway system, as a representative of crowded cities, show that ever increasing commutation demand results in rapid decline in service quality and satisfaction level, system capacity wastage, and poorer system performance. Since passenger boarding/alighting period is noticeable compared to the inter-station travel time, it seems that passenger boarding/alighting management would play a significant role in system performance improvement. Aiming at increasing satisfaction level and service success rate, while reducing travel time, different boarding/alighting strategies are proposed. Passengers behaviors are carefully simulated based on a microscopic model, through introducing an inclination function which governs a passengers movement in a two-dimensional queue. Simulation results, in terms of three aforementioned measures of performance, show that in less crowded stations, the first strategy, expectedly, outperforms the other two. However, in crowded stations (e.g. interchange stations) the third strategy outperforms the others significantly.
Industry-University Student Collaboration to Develop Sustainability Metric for Concrete Tie Production
Authors: Sutton David B. , Lautala Pasi T. , Dewey George R. , Duong Pelle N.
Published: July 2013

This paper presents the sustainability assessment and a prototype sustainability model, completed by students in the Michigan Tech University (MTU) Transportation Enterprise (TE), for a concrete tie production plant owned by L.B. Foster’s wholly owned subsidiary, CXT, Inc. (CXT), located in Spokane, WA. The paper will provide a short introduction of the Undergraduate Enterprise Program at Michigan Tech, discuss the organizational commitments, coordination and communication needed between partners to conduct the project and highlight some of the challenges and lessons learned during the project. It will summarize the outcomes of the project investigations and modeling efforts with emphasis on the prototype environmental sustainability model to calculate the carbon footprint of the CXT plant and to assess possible areas of improvement. The paper will also review parallel research conducted on recycling methods for concrete ties.
Challenges in Current Wireless Sensor Technology for Railcar Status Monitoring for North America’s Freight Railroad Industry
Authors: Rakshit Sushanta Mohan , Hempel Michael , Sharif Hamid , Punwani John , Stewart Monique , Mehrvarzi Shahram
Published: July 2013

Ensuring rail safety is a priority for the Federal Railroad Administration (FRA) and the railroad industry in North America. One such endeavor is to leverage Wireless Sensor Networks (WSN) to monitor and report in real-time the status of mechanical and electrical components for each railcar, and in conjunction with other railroad subsystems, ensure the safety, security and integrity of transported goods.

The envisioned solution utilizes sensors installed on each railcar to form a train-based wireless network and collect real-time (or near real-time) information on different elements of a train and transmit aggregated information to the locomotive, dispatch centers or regional offices for early fault detection and accident prevention. The railroads have been interested in using a standards-based low-cost communication protocol for this purpose, such as IEEE 802.15.4, often referred to as ZigBee.

Our results show, however, that ZigBee was designed for smaller wireless networks, such as a single railcar. It exhibits several critical problems associated with the unique network topology found on a freight train and the size of such a network. In essence, the network would take the shape of a very long chain of nodes. Some of the problems stemming from this topology are excessively long synchronization delays for establishing the network along the entire train, severe problems with route discovery and maintenance necessary for selecting the next relay node along the chain, aggregation of data errors and a resulting unacceptable packet loss rate, the lack of a traffic prioritization mechanism to protect important packets such as those containing critical alarms of equipment failure, and many more.

In this paper, we describe our findings and experiences in our evaluation of ZigBee for railcar monitoring onboard freight trains, a detailed analysis of the identified problems and their impact on the envisioned railcar monitoring as well as discuss potential solutions to these problems.
Multiple Regression Analysis of the Impact of Track Geometry on Wheel-Rail Forces
Authors: Huang Wei , Liu Yan , Preston-Thomas Jon
Published: July 2013

One of the fundamental keys to improving track safety standards is to establish a strong correlation between track geometry variations and wheel-rail force parameters that are indicators of vehicle-track safety performance. In this study, wheel-rail forces were collected during field tests of a loaded lumber car and an empty tank car. Computer models of the two tested freight cars were built, and the models were calibrated using field test results. The computer models were then used to evaluate the impact of varying track geometry parameters on track safety using the maximum single wheel L/V ratio, maximum truck side L/V ratio, and minimum vertical wheel load ratio. It was confirmed again that the correlations between these force parameters and any individual geometry parameter were weak. With further investigation, it was found that much better correlation can be achieved using multiple regression techniques to define each wheel-rail force parameter as a function of all track geometry parameters combined together. Expressions of the maximum truck side L/V ratio, maximum single wheel L/V ratio, and minimum vertical wheel load ratio were obtained as functions of curvature, cross level, alignment, gauge, and cant deficiency using multiple regression analysis.