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In recent years there has been increasing interest in quantifying the emissions from aircraft in order to generate inventories of emissions for climate models, technology and scenario studies, and inventories of emissions for airline fleets typically presented in environmental reports. The preferred method for calculating aircraft engine emissions of NOx, HC, and CO is the proprietary “P3T3” method. This method relies on proprietary airplane and engine performance models along with proprietary engine emissions characterizations. In response and in order to provide a transparent method for calculating aircraft engine emissions non proprietary fuel flow based methods 1,2,3 have been developed. This paper presents derivation, updates, and clarifications of the fuel flow method methodology known as “Fuel Flow Method 2”.

Abstract An investigation into the pre-ashing of new gasoline particulate filters (GPFs) has demonstrated that the filtration efficiency of such filters can be improved by up to 30% (absolute efficiency improvement) when preconditioned using ash derived from a fuel-borne catalyst (FBC) additive. The additive is typically used in diesel applications to enable diesel particulate filter (DPF) regeneration and can be added directly into the fuel tank of the vehicle. This novel result was compared with ash derived from lube oil componentry, which has previously been shown to improve filtration efficiency in GPFs. The lube oil-derived ash utilized in this work improved the filtration efficiency of the GPF by −30%, comparable to the ash derived from the FBC additive.

“Zoning” a catalytic converter involves placing higher concentrations of platinum group metals (PGM) in the inlet portion of the substrate. This is done to optimize the cost-to-performance tradeoff by increasing the reaction rate at lower temperatures while minimizing PGM usage. A potentially useful application of catalyst zoning is to improve performance using a constant PGM mass. A study was performed to assess what the optimum ratio of front to rear palladium zone length is to achieve the highest performance in vehicle emission testing. Varying the zone ratio from 1:1 to 1:9 shows a clear hydrocarbon performance optimum at a 1:5.66 (15%/85%) split. This performance optimum shows as both a minimum in FTP75 non-methane organic gas (NMOG) emissions as well as a minimum in hydrocarbon, carbon monoxide, and nitrogen oxide light-off temperature. Overall, an improvement of 18%, or 11 mg/mi of combined NMOG+NOx emissions was obtained without using additional PGM.

A program has been completed to evaluate ultra-low sulfur diesel fuels and passive diesel particulate filters (DPFs) in truck and bus fleets operating in southern California. The fuels, ECD and ECD-1, are produced by ARCO (a BP Company) and have less than 15 ppm sulfur content. Vehicles were retrofitted with two types of catalyzed DPFs, and operated on ultra-low sulfur diesel fuel for over one year. Exhaust emissions, fuel economy and operating cost data were collected for the test vehicles, and compared with baseline control vehicles. Regulated emissions are presented from two rounds of tests. The first round emissions tests were conducted shortly after the vehicles were retrofitted with the DPFs. The second round emissions tests were conducted following approximately one year of operation. Several of the vehicles retrofitted with DPFs accumulated well over 100,000 miles of operation between test rounds.

The experimental XA-100 is a 5-passenger 4-door Chevrolet Corsica that has been retrofitted with an electric-motor propulsion system, batteries, and an on-board engine/alternator system. The XA-100 is designed 1) to travel on around-town and short freeway commute trips on battery power alone with zero exhaust emissions (zero-emissions vehicle (ZEV)) and 2) to travel as an ultra-low-emissions vehicle (ULEV) on long distance trips using an on-board engine/alternator (i.e., an auxiliary power unit (APU)) for electric power. In all other respects (e.g., performance, handling, user interface), the XA-100 is designed to retain the characteristics of the conventional Corsica to the greatest degree possible. The XA-100 was developed as a result of research sponsored in part by the California Energy Commission (CEC), with labor donated by members of the Electric Auto Association (EAA) and faculty, staff and students of Stanford University.

An international standard for nonroad engines has been developed that comprises gaseous and particulate emissions measurement procedures, smoke testing, test cycles, and an engine family and group concept. Through a joint effort of industry and government agencies, ISO 8178 has become the basis for emissions legislation in the USA, the European Union and Japan and of the International Maritime Organization. The ultimate goal of worldwide harmonization for the worldwide engine industry has been reached, but much effort is still needed to maintain the level of harmonization achieved today. The validity of ISO 8178 has been demonstrated on a round robin test with three engines of 19 to 170 kW circulated around 28 test laboratories. Test-to-test repeatability was generally lower than 10 %. Lab-to-lab variability was less than 10 % for NOx and particulates, and over 25 % for HC and CO. The equivalence of partial flow and full flow dilution systems for particulates has been proven.

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).

The accumulation of waste products aboard spacecraft during manned missions of long duration still is an unsolved problem. Even if life support systems with regeneration of water (from urine and condensates) and oxygen are installed, waste accumulates at such a fast rate that within a short time storage space problems are encountered. Also, additional weight is required to provide a means of processing the waste material. To date, spacecraft designers have considered life support systems and rocket propulsion systems as independent subsystems of a manned spacecraft. The Integrated Waste Management/Rocket Propulsion System concept developed by Rocket Research Corp. under NASA Contract NAS 1–6750, has demonstrated that human waste products can form a useful propellant ingredient and provide propulsion, as well as be an effective means of removing and sterilizing spacecraft waste.

Ethyl tertiary-butyl ether (ETBE), a reaction product of ethanol and isobutylene, has been proposed as a high-octane blending component for gasoline. Laboratory studies have been conducted to determine how the addition of ETBE to gasoline affects the volatility characteristics of the fuel, and how the effects of ETBE compare with those of the commonly used oxygenates, ethanol and MTBE. The amount of vapor generated in bench-scale simulated evaporative emissions tests with each of those three oxygenates was also determined. The vapor pressures of gasoline-ETBE blends decreased linearly as the concentration of ETBE was increased. In contrast, ethanol addition raises the vapor pressure of gasoline, although in a nonlinear fashion. ETBE increased the mid-range volatility of the fuel, in the same way as a pure hydrocarbon of similar vapor pressure and boiling point.

Researchers at the Powertrain Control Research Laboratory (PCRL) at the University of Wisconsin-Madison have developed a transient test system for single-cylinder engines that accurately replicates the dynamics of a multi-cylinder engine. The overall system can perform very rapid transients in excess of 10,000 rpm/second, and also replicates the rotational dynamics, intake gas dynamics, and heat transfer dynamics of a multi-cylinder engine. Testing results using this system accurately represent what would be found in the multi-cylinder engine counterpart. Therefore, engine developments can be refined to a much greater degree at lower cost, and these changes directly incorporated in the multi-cylinder engine with minimal modification. More importantly, various standardized emission tests such as the cold-start, FTP or ETC, can be run on this single-cylinder engine.

Viking 29 is being built under a U.S. Department of Energy contract by the Vehicle Research Institute (VRI) at Western Washington University and JX Crystals of Issaquah, WA to demonstrate a thermophotovoltaic (TPV) generator. The 10 kW TPV generator being developed for use in a vehicle makes use of gallium antimonide (GaSb) photovoltaic (PV) cells surrounding a central emitter heated by a compressed natural gas flame to 1700 Kelvin. The infrared photons generated activate the PV cells to produce electricity which maintains a charge in the battery. Preliminary emission testing has shown that this generator is 50 times cleaner than an equivalent internal combustion engine (ICE).

Since 1992 (for one vehicle since 1989) MTC has regularly performed emission tests on some vehicles equipped with closed-loop lambda-regulated Otto engines and catalysts. The vehicles are passenger cars of different kinds and emission control ""generations."" They are standard vehicles fulfilling Swedish A12 emission control limits, later on the EU emission limits. Some of them are also certified according to Swedish environmental class 1 and 2. The most advanced vehicle tested is certified according to US ULEV regulations. The vehicles with the highest mileage have been followed for more than 250,000 km with tests at yearly intervals. The vehicles were in the beginning tested according to the test cycle to which they were certified. Later on, other test cycles and steady-state tests were applied to the vehicles, as well as cold start tests at -7°C.

A 28-vehicle fleet test was executed to verify and quantify the NOX emissions reductions achieved through the use of Infineum's Vektron 6913 gasoline additive. The fleet composition and experimental design were finalized in collaborative discussions with US Environmental Protection Agency (EPA) Office of Transportation & Air Quality (OTAQ) and consultation / advice from several major US automotive manufacturers. The test was conducted over a period of five months at Southwest Research Institute. Statistical analysis of the emissions data indicated a 10% average fleet reduction in NOX emissions without any negative impact on other criteria pollutants (CO, HC) or fuel economy.

The regeneration behaviour of the ceramic diesel particulate filter is investigated. It is found that regeneration of the vaporizable components absorbed by the soot is promoted. The addition of manganese leads to a second conversion maximum. When additives are used, ceramic filters pass through a “running-in” phase. As regards Mn emissions, emissions of Mn oxides of all valency stages as well as Mn-SO4may occur. These emissions amount to a maximum of 2.2 µg Mn/mile. Dispersion calculations for worst case situations have shown, that the maximum Mn-immission caused by using manganese fuel additives is still within the level of present immissions. Families of characteristics are shown for emissions of the diesel particulate filter for particles and NOx. By using filters with higher efficiency the particulate emissions may fall below 0,08g/miie. The particulate filter and the additive metering system have proved satisfactory in a field test in the US.

Due to the constant need of improvement of the national vehicles, seeking the attendance to the legal limits of vehicular emissions, defined by CONAMA, AEA - Brazilian Association of Automotive Engineering, through its Technical Commission of Accreditation of Laboratories of Emissions, together with INMETRO, coordinated an wide proficiency testing. This correlation involved all the national emission laboratories, which consisted of performing complete of exhaust emission tests, according to brazilian standards ABNT NBR 6601/2001 and NBR 12026/2002. The objective of this work is the presentation of the obtained results and the demonstration of the current quality of the national laboratories.

The Environmental Protection Agency published a paper in November of 1985 (“Study of Gasoline Volatility and Hydrocarbon Emissions from Motor Vehicles”, EPA-AA-SDSB-85-5) suggesting that the evaporative emission test fuel be modified to reflect current “in-use” fuel characteristics. It was shown that higher evaporative emissions resulted from current vehicles when tested on higher RVP fuels. Vehicle tank fuel volatility decreases as the lighter ends in the fuel evaporate. As fuel is used in vehicle operation, the remainder in the tank becomes less volatile. The evaporative emission test procedure specifies that the test be conducted with the tank at 40% of capacity. At this level, one would expect the fuel to have “weathered” and be of less volatility than originally dispensed. This factor was not included in the EPA data.

The strong focus on reducing brake drag, driven by a historic ramp-up in global fuel economy and carbon emissions standards, has led to renewed research on brake caliper drag behaviors and how to measure them. However, with the increased knowledge of the range of drag behaviors that a caliper can exhibit comes a particularly vexing problem - how should this complex range of behaviors be represented in the overall road load of the vehicle? What conditions are encountered during coastdown and fuel economy testing, and how should brake drag be measured and represented in these conditions? With the Environmental Protection Agency (amongst other regulating agencies around the world) conducting audit testing, and the requirement that published road load values be repeatable within a specified range during these audits, the importance of answering these questions accurately is elevated. This paper studies these questions, and even offers methodology for addressing them.

Fuel economy estimates are provided for the CleanFleet vans operated for two years by FedEx in Southern California. Between one and three vehicle manufacturers (Chevrolet, Dodge, and Ford) supplied vans powered by compressed natural gas (CNG), propane gas, California Phase 2 reformulated gasoline (RFG), methanol (M-85), and unleaded gasoline as a control. Two electric G-Vans, manufactured by Conceptor Corporation, were supplied by Southern California Edison. Vehicle and engine technologies are representative of those available in early 1992. A total of 111 vans were assigned to FedEx delivery routes at five demonstration sites. The driver and route assignments were periodically rotated within each site to ensure that each vehicle would experience a range of driving conditions. Regression analysis was used to estimate the relationships between vehicle fuel economy and factors such as the number of miles driven and the number of delivery stops made each day.

To meet US EPA light-duty vehicle emission standards, the vehicle powertrain has to be optimally controlled in addition to maintaining very high catalyst system efficiency. If vehicles are operated outside the bounds of a standard laboratory exhaust emission test (e.g., on-road or off-cycle) the operating control strategy may shift to optimize other desirable parameters such as fuel economy and drivability. Under these circumstances. The engine control system could be operating in a different state space from an emission control stand point. This control state-space can be observed based on four principal parameters: NOx, Lambda and exhaust temperature (measured at the tailpipe) and vehicle acceleration. These vehicle emission control patterns can be characterized by their corresponding emission control signatures, such as cold start, transient fuel control, and high speed/high load open loop. These emission control signatures are unique to a variety of engine technologies as well.

Five late model vehicles equipped with representative emission control systems were used to determine the effect of benzene concentration of gasolines on evaporative and exhaust benzene emissions. The vehicle selection included three different fuel induction systems and two different exhaust emissions control systems. The test fuels consisted of 25 and 40% aromatic base fuels each at four benzene levels ranging from 0.02 to 4%. Evaporative and exhaust determinations included measurement of regulated emission components and benzene emission in each test segment. Benzene level in the fuel tank head space was also measured. In addition to the above evaporative and exhaust emission test program, exhaust samples were collected simultaneously before and after the exhaust emissions control system to determine engine-out and tailpipe-out emission rates as well as the catalyst conversion efficiency.