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Viewing 1 to 30 of 78
Technical Paper
2014-04-01
Peter Bonsack, Ross Ryskamp, Marc Besch, Daniel Carder, Mridul Gautam, John Nuszkowski
Abstract Due to tightening emission legislations, both within the US and Europe, including concerns regarding greenhouse gases, next-generation combustion strategies for internal combustion diesel engines that simultaneously reduce exhaust emissions while improving thermal efficiency have drawn increasing attention during recent years. In-cylinder combustion temperature plays a critical role in the formation of pollutants as well as in thermal efficiency of the propulsion system. One way to minimize both soot and NOx emissions is to limit the in-cylinder temperature during the combustion process by means of high levels of dilution via exhaust gas recirculation (EGR) combined with flexible fuel injection strategies. However, fuel chemistry plays a significant role in the ignition delay; hence, influencing the overall combustion characteristics and the resulting emissions. Therefore, the Fuels for Advanced Combustion Engines (FACE) Working Group of the Coordinating Research Council (CRC) specified and formulated a matrix of nine test fuels for advanced combustion engines based on the variation of three properties: cetane number, aromatic content, and 90 percent distillation temperature.
Technical Paper
2013-09-17
Jay Wilhelm, Christopher Gioia, Wade Huebsch, Mridul Gautam
A Hybrid Projectile (HP) is a tube launched munition that transforms into a gliding UAV, and is currently being researched at West Virginia University. In order to properly transform, the moment of transformation needs to be controlled. A simple timer was first envisioned to control transformation point for maximum distance. The distance travelled or range of an HP can directly be modified by varying the launch angle. In addition, an internal timer would need to be reprogrammed for any distance less than maximum range due to the nominal time to deployment varying with launch angle. A method was sought for automatic wing deployment that would not require reprogramming the round. A body angle estimation system was used to estimate the pitch of the HP relative to the Earth to determine when the HP is properly oriented for the designed glide slope angle. It also filters out noise from an inertial measurement unit (IMU). An Extended Kalman Filter (EKF) was used to estimate the pitch of the HP while an algorithm determines when to deploy the wings.
Technical Paper
2013-09-17
Jay Wilhelm, Joesph Close, Wade Huebsch, Mridul Gautam
A Hybrid Projectile (HP) is a round that transforms into a UAV after being launched. Some HP's are fired from a rifled barrel and must be de-spun and wings-level for lifting surfaces to be deployed. Control surfaces and controllers for de-spinning and wings-leveling were required for initial design of an HP 40 mm. Wings, used as lifting surfaces after transformation, need to be very close to level with the ground when deployed. First, the tail surface area needed to de-spin a 40 mm HP was examined analytically and simulated. Next, a controller was developed to maintain a steady de-spin rate and to roll-level the projectile in preparation of wing deployment. The controller was split into two pieces, one to control de-spin, and the other for roll-leveling the projectile. An adaptable transition point for switching controllers was identified analytically and then adjusted by using simulations. The initial roll position may never be the same due to the round being inserted into its launch tube at any roll angle, therefore an adaptable method was used to shorten the time required to become wings-level.
Technical Paper
2013-09-17
Patrick H. Browning, Mridul Gautam, Wade Huebsch
This paper documents the numerical and experimental investigation of a new type of wing section being developed at West Virginia University that shows good potential for use in wings in low Reynolds number flows. These wing sections have been designed with a minimum number of flat sides, or facets, which are arranged in such a way as to promote flow over the surface similar to traditional smooth airfoil shapes, but without the complexity of the typically highly contoured airfoil form. 2D numerical techniques have been employed to determine appropriate geometric limitations of the wing section facets, and finite span wings comprised of these faceted wing sections have been tested in wind tunnels in wing-only and wing-plus-body configurations to determine their basic aerodynamic performance. The latest results of these efforts, as well as some speculation as to the mechanisms at work are presented.
Technical Paper
2013-09-08
Hemanth Kappanna, Marc Besch, Arvind Thiruvengadam, Oscar Delgado, Alessandro Cozzolini, Daniel Carder, Mridul Gautam, Shaohua Hu, Tao Huai, Alberto Ayala, Adewale Oshinuga, Randall Pasek
The study was aimed at assessing in-use emissions of a USEPA 2010 emissions-compliant heavy-duty diesel vehicle powered by a model year (MY) 2011 engine using West Virginia University's Transportable Emissions Measurement System (TEMS). The TEMS houses full-scale CVS dilution tunnel and laboratory-grade emissions measurement systems, which are compliant with the Code of Federal Regulation (CFR), Title 40, Part 1065 [1] emissions measurement specifications. One of the specific objectives of the study, and the key topic of this paper, is the quantification of greenhouse gas (GHG) emissions (CO2, N2O and CH4) along with ammonia (NH3) and regulated emissions during real-world operation of a long-haul heavy-duty vehicle, equipped with a diesel particulate filter (DPF) and urea based selective catalytic reduction (SCR) aftertreatment system for PM and NOx reduction, respectively. The TEMS was additionally outfitted with an MKS MultiGas® 2030-HS high-speed FTIR to quantify NH3 and N2O, along with other compounds of interest, at a frequency of 5 Hz.
Technical Paper
2013-09-08
Daniele Littera, Alessandro Cozzolini, Marc Besch, Mario Velardi, Daniel Carder, Mridul Gautam
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. In light of this, the study of the exhaust plume of a heavy duty diesel vehicle operated inside a subsonic environmental wind tunnel can give us an idea of the dilution process and the representative emissions of the real world scenario.
Technical Paper
2013-09-08
Alessandro Cozzolini, Daniele Littera, Ross Ryskamp, John Smallwood, Marc Besch, Mario Velardi, Hemanth Kappanna, Daniel Carder, Mridul Gautam
The need for a cleaner and less expensive alternative energy source to conventional petroleum fuels for powering the transportation sector has gained increasing attention during the past decade. Special attention has been directed towards natural gas (NG) which has proven to be a viable option due to its clean-burning properties, reduced cost and abundant availability, and therefore, lead to a steady increase in the worldwide vehicle population operated with NG. The heavy-duty vehicle sector has seen the introduction of natural gas first in larger, locally operated fleets, such as transit buses or refuse-haulers. However, with increasing expansion of the NG distribution network more drayage and long-haul fleets are beginning to adopt natural gas as a fuel. Traditionally, natural gas engines are operated over an Otto-cycle employing a stoichiometric combustion strategy, and using sparkplugs to ignite the fuel and a three-way catalyst (TWC) to mitigate emissions of NOx, CO as well as HC.
Technical Paper
2012-06-01
Nigel Clark, David L. McKain, W Wayne, Daniel Carder, Mridul Gautam
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. Fuel economy during evaluations representing half passenger load, which represented a 10% higher vehicle weight than empty weight, were 6% over the Paris driving schedule and 3% lower over the Cruise schedule than that observed during evaluations representative of empty/curb weight.
Technical Paper
2011-10-18
Robert F. Minehart, Patrick Browning, Jay Wilhelm, Shanti Hamburg, Mridul Gautam, Wade Huebsch
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. Comparison of the designs is based on their respective continuous volume ratio (r c v ), which is calculated by comparing the single largest payload volume (V s ) available in a projectile to the total projectile volume (V t ).
Technical Paper
2011-10-18
Jay Wilhelm, Patrick Browning, Mridul Gautam, Wade Huebsch
Tube Launched-Unmanned Air Vehicles (TL-UAV) are munitions that alter their trajectories during flight to enhance the capabilities by possibly extending range, increasing loiter time through gliding, and/or having guided targeting capabilities. Traditional munition systems, specifically the tube-launched mortar rounds, are not guided. Performance of these "dumb" munitions could be enhanced by updating to TL-UAV and still utilize existing launch platforms with standard propellant detonation firing methods. The ability to actively control the flight path and extend range of a TL-UAV requires multiple onboard systems which need to be identified, integrated, assembled, and tested to meet cooperative function requirements. The main systems, for a mortar-based TL-UAV being developed at West Virginia University (WVU), are considered to be a central hub to process information, aerodynamic control devices, flight sensors, a video camera system, power management, and a wireless transceiver. A camera is used to provide video for a "man-in-the-loop" operator to steer the munition.
Technical Paper
2011-09-11
Daniele Littera, Marc Besch, Alessandro Cozzolini, Daniel Carder, Arvind Thiruvengadam, Adam Sayres, Hemanth Kappanna, Mridul Gautam, Adewale Oshinuga
In order to comply with stringent 2010 US-Environmental Protection Agency (EPA) on-road, Heavy-Duty Diesel (HDD) emissions regulations, the Selective Catalytic Reduction (SCR) aftertreatment system has been judged by a multitude of engine manufacturers as the primary technology for mitigating emissions of oxides of nitrogen (NOx). As virtually stand-alone aftertreatment systems, SCR technology further represents a very flexible and efficient solution for retrofitting legacy diesel engines as the most straightforward means of cost-effective compliance attainment. However, the addition of a reducing agent injection system as well as the inherent operation limitations of the SCR system due to required catalyst bed temperatures introduce new, unique problems, most notably that of ammonia (NH₃) slip. Even the most refined systems, while performing flawlessly during standardized certification tests, may encounter excursions during real-world operation, thereby leading to possible formation of secondary emissions and emit unacceptable high NOx.
Technical Paper
2011-09-11
Vincenzo Mulone, Alessandro Cozzolini, Prabash Abeyratne, Marc Besch, Daniele Littera, Mridul Gautam
Diesel Particulate Filters (DPFs) are well assessed exhaust aftertreatment devices currently equipping almost every modern diesel engine to comply with the most stringent emission standards. However, an accurate estimation of soot content (loading) is critical to managing the regeneration of DPFs in order to attain optimal behavior of the whole engine-after-treatment assembly, and minimize fuel consumption. Real-time models can be used to address challenges posed by advanced control systems, such as the integration of the DPF with the engine or other critical aftertreatment components or to develop model-based OBD sensors. One of the major hurdles in such applications is the accurate estimation of engine Particulate Matter (PM) emissions as a function of time. Such data would be required as input data for any kind of accurate models. The most accurate way consists of employing soot sensors to gather the real transient soot emissions signal, which will serve as an input to the model. Objective of this study is model a DPF in real-time by means of the 1-D code ExhAUST (Exhaust Aftertreatment Unified Simulation Tool).
Technical Paper
2011-09-11
Alessandro Cozzolini, Vincenzo Mulone, Prabash Abeyratne, Daniele Littera, Mridul Gautam
Diesel particulate filters (DPFs) are recognized as the most efficient technology for particulate matter (PM) reduction, with filtration efficiencies in excess of 90%. Design guidelines for DPFs typically are: high removal efficiency, low pressure drop, high durability and capacity to resist high temperature excursions during regeneration events. The collected mass inside the trap needs to be periodically oxidized to regenerate the DPF. Thus, an in-depth understanding of filtration and regeneration mechanisms, together with the ability of predicting actual DPF conditions, could play a key role in optimizing the duration and number of regeneration events in case of active DPFs. Thus, the correct estimation of soot loading during operation is imperative for effectively controlling the whole engine-DPF assembly and simultaneously avoidingany system failure due to a malfunctioning DPF. A viable way to solve this problem is to use DPF models. This paper presents a DPF model jointly developed by West Virginia University and University of Rome Tor Vergata.
Technical Paper
2010-10-05
Nigel Clark, David L. McKain, Petr Sindler, Ronald Jarrett, John Nuszkowski, Mridul Gautam, W Wayne, Gregory Thompson, Ricky Sonny
Fuel economy and regulated emissions were measured from eight forty-foot transit buses operated on petroleum diesel and a “B20” blend of 80% diesel fuel and 20% biodiesel by volume. Use of biodiesel is attractive to displace petroleum fuel and reduce an operation's carbon footprint. Usually it is assumed that biodiesel will also reduce particulate matter (PM) emissions relative to those of petroleum diesel. Model years of the vehicles evaluated were newer 2007-08 Gillig low-floor buses, 2005 Gillig Phantom buses, and a 2002 Gillig Phantom bus. Engine technology represented three different emissions standards, and included buses with OEM diesel particulate filters. Each bus was evaluated using two transient speed-time schedules, the Orange County Transit Authority (OCTA) driving schedule which represents moderate speed urban/suburban operation and the Urban Dynamometer Driving Schedule (UDDS) which represents a mix of suburban and higher speed on-highway operation. On road coast down runs confirmed that the road load was appropriate.
Technical Paper
2010-10-05
Idowu Olatunji, Scott Wayne, Mridul Gautam, Nigel Clark, Gregory Thompson, David McKain, Petr Sindler, John Nuszkowski
Biodiesel may be derived from either plant or animal sources, and is usually employed as a compression ignition fuel in a blend with petroleum diesel (PD). Emissions differences between vehicles operated on biodiesel blends and on diesel have been published previously, but data do not cover the latest engine technologies. Prior studies have shown that biodiesel offers advantages in reducing particulate matter, with either no advantage or a slight disadvantage for oxides of nitrogen emissions. This paper describes a recent study on the emissions impact of two biodiesel blends B20A, made from 20% animal fat (tallow) biodiesel and 80% PD, and B20B, obtained from 20% soybean biodiesel and 80% PD. These blends used the same PD fuel for blending and were contrasted with the same PD fuel as a reference. The research was conducted on a 2007 medium heavy-duty diesel truck (MHDDT), with an engine equipped with Exhaust Gas Recirculation (EGR) and a Diesel Particulate Filter (DPF). The truck's emissions were characterized under steady state conditions under three driving modes namely Mode1 (MD1), Mode2 (MD2) and Mode3 (MD3) using the West Virginia University's Transportable Heavy-Duty Chassis Dynamometer Emissions Testing Laboratory.
Technical Paper
2009-04-20
Michelangelo Ardanese, Raffaello Ardanese, Marc C. Besch, Theodore R. Adams, Venkata Sathi, Benjamin C. Shade, Mridul Gautam, Adewale Oshinuga, Matt Miyasato
For engine operations involving low load conditions for an extended amount of time, the exhaust temperature may be lower than that necessary to initiate the urea hydrolyzation. This would necessitate that the controller interrupt the urea supply to prevent catalyst fouling by products of ammonia decomposition. Therefore, it is necessary for the engine controller to have multiple calibrations available in regions of engine operation where the aftertreatment does not perform well, so that optimal exhaust conditions are guaranteed during the wide variety of engine operations. In this study the test engine was equipped with a catalyzed diesel particulate filter (DPF) and a selective catalytic reduction system (SCR), and programmed with two different engine calibrations, namely the low-NOx and the low fuel consumption (low-FC). The low-NOx calibration, to be used in case of insufficient heat in the exhaust stream, was developed to meet the 2010 emission standards for heavy-duty diesel engines.
Technical Paper
2009-04-20
Raffaello Ardanese, Michelangelo Ardanese, Marc C. Besch, Theodore R. Adams, Arvind Thiruvengadam, Benjamin C. Shade, Mridul Gautam, Adewale Oshinuga, Matt Miyasato
The temporary deactivation of the selective catalytic reduction (SCR) device due to malfunction requires the engine control to engage multiple engine-out calibrations. Further, it is expected that emitted particles will be different in composition, size and morphology when an engine, which meets the 2010 particulate matter (PM) gravimetric limits, is programmed with multiple maps. This study investigated the correlation between SCR-out/engine-out PM emissions from an 11-liter Volvo engine. Measurement of PM concentrations and size distributions were conducted under steady state and transient cycles. Ion Chromatograph analysis on gravimetric filters at the SCR-out has revealed the presence of sulfates. Two different PM size-distributions were generated over a single engine test mode in the accumulation mode region with the aid of a design of experiment (DOE) tool. The SCR-out PM size distributions were found to correlate with the two engine-out distributions.
Technical Paper
2008-04-14
Gregory J. Thompson, Daniel K. Carder, Nigel N. Clark, Mridul Gautam
As part of the 1998 Consent Decrees concerning alternative ignition strategies between the six settling heavy-duty diesel engine manufacturers and the United States government, the engine manufacturers agreed to perform in-use emissions measurements of their engines. As part of the Consent Decrees, pre- (Phase III, pre-2000 engines) and post- (Phase IV, 2001 to 2003 engines) Consent Decree engines used in over-the-road vehicles were tested to examine the emissions of oxides of nitrogen (NOx) and carbon dioxide (CO2). A summary of the emissions of NOx and CO2 and fuel consumption from the Phase III and Phase IV engines are presented for 30 second “Not-to-Exceed” (NTE) window brake-specific values. There were approximately 700 Phase III tests and 850 Phase IV tests evaluated in this study, incorporating over 170 different heavy duty diesel engines spanning 1994 to 2003 model years. Test vehicles were operated over city, suburban, and highway routes. The results show that the post Consent Decree engines' 30 second NTE brake-specific NOx values were below the NOx NTE allowance limit.
Technical Paper
2008-04-14
Benjamin C. Shade, Daniel K. Carder, Gregory J. Thompson, Mridul Gautam
A work-based window method has been developed to calculate in-use brake-specific oxides of nitrogen (NOx) emissions for all engine speeds and engine loads. During an in-use test, engine speed and engine torque are read from the engine's electronic control unit, and along with time, are used to determine instantaneous engine power. Instantaneous work is calculated using this power and the time differential in the data collection. Work is then summed until the target amount of work is accumulated. The emissions levels are then calculated for that window of work. It was determined that a work window equal to the theoretical Federal Test Procedure (FTP) cycle work best provides a means of comparison to the FTP certification standard. Also, a failure criterion has been established based on the average amount of power generated in the work window and the amount of time required to achieve the target work window to determine if a particular work window is valid. Data collected during Phase IV of West Virginia University's in-use testing program were used to show that the work window method produces in-use brake-specific NOx values similar to the 30 second Not-To-Exceed (NTE) window method, which was applicable at the time of testing, and the continuous NTE window method over different highway and urban test routes for a variety of engine configurations.
Technical Paper
2007-08-05
Nigel N. Clark, ABM S. Khan, W. Scott Wayne, Mridul Gautam, Gregory J. Thompson, David L. McKain, Donald W. Lyons, Ryan Barnett
Transit agencies across the United States operate bus fleets primarily powered by diesel, natural gas, and hybrid drive systems. Passenger loading affects the power demanded from the engine, which in turn affects distance-specific emissions and fuel consumption. Analysis shows that the nature of bus activity, taking into account the idle time, tire rolling resistance, wind drag, and acceleration energy, influences the way in which passenger load impacts emissions. Emissions performance and fuel consumption from diesel and natural gas powered buses were characterized by the West Virginia University (WVU) Transportable Emissions Testing Laboratory. A comparison matrix for all three bus technologies included three common driving cycles (the Braunschweig Cycle, the OCTA Cycle, and the ADEME-RATP Paris Cycle). Each bus was tested at three different passenger loading conditions (empty weight, half weight, and full weight). Carbon dioxide (CO2) from a John Deere powered natural gas bus was higher at full weight than that at empty test weight.
Technical Paper
2007-04-16
Dustin L. McIntyre, Steven D. Woodruff, Steven W. Richardson, Michael H. McMillian, Mridul Gautam
To meet the ignition system needs of large bore high pressure lean burn natural gas engines a laser diode side pumped passively Q-switched laser igniter was designed and tested. The laser was designed to produce the optical intensities needed to initiate ignition in a lean burn high brake mean effective pressure (BMEP) engine. The experimentation explored a variety of optical and electrical input parameters that when combined produced a robust spark in air. The results show peak power levels exceeding 2 MW and peak focal intensities above 400 GW/cm2. Future research avenues and current progress with the initial prototype are presented and discussed.
Technical Paper
2007-01-23
Yuebin Wu, Nigel N. Clark, Daniel Carder, Gregory J. Thompson, Mridul Gautam, Donald W. Lyons
Heavy-Duty Diesel (HDD) engines' particulate matter (PM) emissions are most often measured quantitatively by weighing filters that collect diluted exhaust samples pre- and post-test. PM sampling systems that dilute exhaust gas and collect PM samples have different effects on measured PM data. Those effects usually contribute to inter-laboratory variance. The U.S. Environmental Protection Agency (EPA)'s 2007 PM emission measurement regulations for the test of HDD engines should reduce variability, but must also cope with PM mass that is an order of magnitude lower than legacy engine testing. To support the design of a 2007 US standard HDD PM emission sampling system, a parametric study based on a systematic Simulink® model was performed. This model acted as an auxiliary design tool when setting up a new 2007 HDD PM emission sampling system in a heavy-duty test cell at West Virginia University (WVU). It was also designed to provide assistance in post-test data processing. Modeling of gas chemical composition, mass, and heat transfer, as well as modeling of the primary and the secondary tunnel, were addressed.
Technical Paper
2007-01-23
Nigel N. Clark, W. Scott Wayne, ABM S. Khan, Donald W. Lyons, Mridul Gautam, David L. McKain, Gregory J. Thompson, Ryan Barnett
Although diesel engines still power most of the heavy-duty transit buses in the United States, many major cities are also operating fleets where a significant percentage of buses is powered by lean-burn natural gas engines. Emissions from these buses are often expressed in distance-specific units of grams per mile (g/mile) or grams per kilometer (g/km), but the driving cycle or route employed during emissions measurement has a strong influence on the reported results. A driving cycle that demands less energy per unit distance than others results in higher fuel economy and lower distance-specific oxides of nitrogen emissions. In addition to energy per unit distance, the degree to which the driving cycle is transient in nature can also affect emissions. Speed correction factors for heavy-duty diesel vehicle oxides of nitrogen emissions have been utilized to account for differences in driving cycles and show that distance-specific emissions have a non-linear relationship with average driving cycle speed.
Technical Paper
2006-10-16
Nigel N. Clark, Mridul Gautam, W. Scott Wayne, Gregory J. Thompson, Ralph D. Nine, Donald W. Lyons, Thomas Buffamonte, Shuhong Xu, Hector Maldonado
Heavy duty diesel vehicle (HDDV) emissions are known to affect air quality, but few studies have quantified the real-world contribution to the inventory. The objective of this study was to provide data that may enable ambient emissions investigators to m,odel the air quality more accurately. The 25 vehicles reported in this paper are from the first phase of a program to determine representative regulated emissions from Heavy Heavy-Duty Diesel Trucks (HHDDT) operating in Southern California. Emissions data were gathered using a chassis dynamometer, full flow dilution tunnel, and research grade analyzers. The subject program employed two truck test weights and four new test modes (one was idle operation), in addition to the Urban Dynamometer Driving Schedule (UDDS), and the AC50/80 cycle. The reason for such a broad test cycle scope was to determine thoroughly how HHDDT emissions are influenced by operating cycle to improve accuracy of models. Overall, it was determined from these Phase 1 data that oxides of nitrogen (NOx) emissions did not decrease in relation to the HHDDT Model Year (MY) and all MY bins produced about 20 g/mile of NOx on the UDDS.
Technical Paper
2006-10-16
Gregory J. Thompson, John C. Gibble, Nigel N. Clark, Mridul Gautam
The 1998 Consent Decrees between the settling heavy-duty diesel engine manufacturers and the United States Government require the engine manufacturer to perform in-use emissions testing to evaluate their engine designs and emissions when the vehicle is placed into service. This additional requirement will oblige the manufacturer to account for real-world conditions when designing engines and engine control algorithms and include driving conditions, ambient conditions, and fuel properties in addition to the engine certification test procedures. Engine operation and ambient conditions can be designed into the engine control algorithm. However, there will most likely be no on-board determination of fuel properties or composition in the near future. Therefore, the engine manufacturer will need to account for varying fuel properties when developing the engine control algorithm for when in-use testing is performed. A comparison of the emissions from a heavy-duty engine has shown that commercially available fuel can dramatically affect the emissions along with the test cycle used to evaluate the emissions.
Technical Paper
2006-10-16
Nathan A. Moynahan, Gregory J. Thompson, Nigel N. Clark, Mridul Gautam
The 1998 Consent Decrees between the United States Government and the settling heavy-duty diesel engine manufacturers require in-use emissions testing from post 2000 model year engines. The emissions gathered from these engines must be reported on a brake-specific mass basis. To report brake-specific mass emissions, three primary parameters must be measured. These are the concentration of each emission constituent, the exhaust mass flow rate, and the engine power output. The measurement of the concentration level and exhaust mass flow rate can be (and are generally) measured directly with instrumentation installed in the exhaust transfer tube. However, engine power cannot be measured directly for in-use emissions testing due to the direct coupling of the engine output shaft to the vehicle's transmission. Engine power can be inferred from the electronic control unit (ECU) broadcast of engine speed and engine torque. The use of engine power from the ECU presents a problem in that one must rely on the accuracy of the manufacturer's broadcast values.
Technical Paper
2005-10-24
Mohan Krishnamurthy, Mridul Gautam
Beginning 2007, heavy-duty engine certification would require that in-use emissions from vehicles be measured under ‘real-world’ operating conditions using on-board measurement devices. An on-board portable emissions measurement system called Mobile Emissions Measurement System (MEMS) was developed at West Virginia University (WVU) to record in-use, continuous and brake-specific emissions from heavy-duty diesel-powered vehicles. The objective of this paper is to present a preliminary development of a test data quality assurance methodology for emissions measured using the any portable emissions measurement system (PEMS). The first stage of the methodology requires ensuring the proper operation of the different sensors and transducers during data collection. The second stage is data synchronization and pre-processing. The next stage is systematic checking of possible errors from transducers and sensors. It should be noted that the methodology discussed focuses on one set of sampling conditioning system and certain measurement technologies, the general discussion on the need for quality assurance and the appropriate methodology to achieve quality assurance remains unchanged.
Technical Paper
2005-10-24
Emily D. Pertl, Daniel K. Carder, Franz A. Pertl, Mridul Gautam, James E. Smith
The Federal Test Procedure (FTP) for heavy-duty engines requires the use of a full-flow tunnel based constant volume sampler (CVS) which is costly to build and maintain, and requires a large workspace. A portable micro-dilution system that could be used for measuring on-board, in use emissions from heavy duty vehicles would be an inexpensive alternative compared to a full-flow CVS tunnel, as well as requiring significantly less workspace. This paper evaluates such a portable particulate matter measuring system. This micro-dilution tunnel operates on the same principle as a full-flow tunnel, however dilution ratios can be more easily controlled with the micro dilution system. The dilution ratios for the micro-dilution system were maintained at least four to one, as per ISO 8178 requirements, by measuring the mass flow rates of the dilution air and dilute exhaust. The unique feature of the micro-dilution system is its use of only a single pump for drawing the diluted exhaust through the micro-dilution tunnel, and supplying filtered, dry dilution gases back to the tunnel.
Technical Paper
2005-10-24
Corey M. Strimer, Nigel N. Clark, Daniel Carder, Mridul Gautam, Gregory Thompson
On-board emissions measurement for heavy-duty vehicles has taken on greater significance because new standards now address in-use emissions levels in the USA. Emissions compliance must be shown in a “Not-to-exceed” (NTE) zone that excludes engine operation at low power. An over-the-road 1996 Peterbilt tractor was instrumented with the West Virginia University Mobile Emissions Measurement System (MEMS). The researchers determined how often the truck entered the NTE, and the emissions from the vehicle, as it was driven over different routes and at different test weights (20,740 lb, 34,640 lb, 61,520 lb, and 79,700 lb) The MEMS interfaced with the truck ECU, while also measuring exhaust flowrate, and concentrations of carbon dioxide (CO2) and oxides of nitrogen (NOx) in the exhaust. The four test routes that were employed included varying terrain types in order to simulate a wide range of on-road driving conditions. One route (called the Bruceton route) included a sustained hill climb. Another route (known as the Saltwell route) traversed more rolling hills throughout the duration of the test.
Technical Paper
2005-10-24
Emily D. Pertl, Daniel K. Carder, Franz A. Pertl, Mridul Gautam, James E. Smith
The Federal Test Procedure (FTP) for heavy-duty engines requires the use of a full-flow tunnel based constant volume sampler (CVS). These are costly to build and maintain, and require a large workspace. A small portable micro-dilution system that could be used on-board, for measuring emissions of in-use, heavy-duty vehicles would be an inexpensive alternative. This paper presents the rationale behind the design of such a portable particulate matter measuring system. The presented micro-dilution tunnel operates on the same principle as a full-flow tunnel, however given the reduced size dilution ratios can be more easily controlled with the micro dilution system. The design targets dilution ratios of at least four to one, in accordance with the ISO 8178 requirements. The unique features of the micro-dilution system are the use of only a single pump and a porous sintered stainless steel tube for mixing dilution air and raw exhaust sample. This paper contains the results of that design process.
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