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A prototype 2007 ISL Cummins diesel engine equipped with a diesel oxidation catalyst (DOC), diesel particle filter (DPF), variable geometry turbocharger (VGT), and cooled exhaust gas recirculation (EGR) was tested at Southwest Research Institute (SwRI) under a high-load accelerated durability cycle for 1000 hours with B20 soy-based biodiesel blends and ultra-low sulfur diesel (ULSD) fuel to determine the impact of B20 on engine durability, performance, emissions, and fuel consumption. At the completion of the 1000-hour test, a thorough engine teardown evaluation of the overhead, power transfer, cylinder, cooling, lube, air handling, gaskets, aftertreatment, and fuel system parts was performed. The engine operated successfully with no biodiesel-related failures. Results indicate that engine performance was essentially the same when tested at 125 and 1000 hours of accumulated durability operation.

A 3-dimensional numerical study has been conducted investigating the combustion process in a VW 1.9l TDI Diesel engine. Simulations were performed modeling the spray injection of a 5-hole Diesel injector in a pressure chamber. A graphical methodology was utilized to match the spray resulting from the widely used Discrete Droplet Spray model to pressure chamber spray images. Satisfactory agreement has been obtained regarding the simulated and experimental spray penetration and cone angles. Thereafter, the combustion process in the engine was simulated. Using engine measurements to initialize the combustion chamber conditions, the compression stroke, the spray injection and the combustion simulation was performed. The novel RTZF two-zone flamelet combustion model was used for the combustion simulation and was tested for partial load operating conditions. An objective analysis of the model is presented including the results of a numerical parameter study.

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment, the load from the electrical components and incident radiation. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. Radiators have no moving parts and are thus simple and highly reliable. However, past freezable radiators have been too heavy.

After several decades of human spaceflight, the community of space-faring nations has accumulated a diverse and sometimes harrowing history of toxicological events that have plagued human space endeavors almost from the very beginning. Some lessons have been learned in ground-based test beds and others were discovered the hard way - when human lives were at stake in space. From such lessons one can build a risk-management framework for toxicological events to minimize the probability of a harmful exposure, while recognizing that we cannot predict all possible events. Space toxicologists have learned that relatively harmless compounds can be converted by air revitalization systems into compounds that cause serious harm to the crew.

An overview is given on the state of the art of a new catalytic exhaust gas aftertreatment device for diesel engines. The function of a precious metal based, flow-through type diesel oxidation catalyst is explained. Much attention is paid to the durability of the diesel oxidation catalyst and especially to the influence of poisoning elements on the catalytic activity. Detailed data on the interaction of poisoning elements such as sulfur, zinc and phosphorus with the catalytic active sites are given. Finally it is demonstrated that it is possible to meet the stringent emission standards for diesel passenger cars in Europe with a new catalyst generation over 80.000 km AMA aging.

In one-dimensional engine simulation programs the simulation of engine performance is mostly done by parameter fitting in order to match simulations with experimental data. The extensive fitting procedure is especially needed for emissions formation - CO, HC, NO, soot - simulations. An alternative to this approach is, to calculate the emissions based on detailed kinetic models. This however demands that the in-cylinder combustion-flow interaction can be modeled accurately, and that the CPU time needed for the model is still acceptable. PDF based stochastic reactor models offer one possible solution. They usually introduce only one (time dependent) parameter - the mixing time - to model the influence of flow on the chemistry. They offer the prediction of the heat release, together with all emission formation, if the optimum mixing time is given.

The California LEV1 II program will be introduced in the year 2003 and requires a further reduction of the exhaust emissions of passenger cars. The cold start emissions represent the main part of the total emissions of the FTP2-Cycle. Cold start emissions can be efficiently reduced by injecting secondary air (SA) in the exhaust port making compliance with the most stringent standards possible. The thermochemical conditions (mixing rate and temperature of secondary air and exhaust gas, exhaust gas composition, etc) prevailing in the exhaust system are described in this paper. This provides knowledge of the conditions for auto ignition of the mixture within the exhaust manifold. The thus established exothermal reaction (exhaust gas post-combustion) results in a shorter time to light-off temperature of the catalyst. The mechanisms of this combustion are studied at different engine idle conditions.

The Spacesuit Water Membrane Evaporator (SWME) is the baseline heat rejection technology selected for development for the Constellation lunar suit. The first SWME prototype, designed, built, and tested at Johnson Space Center in 1999 used a Teflon hydrophobic porous membrane sheet shaped into an annulus to provide cooling to the coolant loop through water evaporation to the vacuum of space. This present study describes the test methodology and planning to compare the test performance of three commercially available hollow fiber materials as alternatives to the sheet membrane prototype for SWME, in particular, a porous hydrophobic polypropylene, and two variants that employ ion exchange through non-porous hydrophilic modified Nafion. Contamination tests will be performed to probe for sensitivities of the candidate SWME elements to ordinary constituents that are expected to be found in the potable water provided by the vehicle, the target feedwater source.

A Total Organic Carbon (TOC) Analyzer has been developed for a Life Sciences Risk Mitigation Flight Experiment to be conducted on Spacehab and the Russian space station, Mir. Initial launch is scheduled for December 1996 (flight STS-81). The analyzer will be tested on the Orbiter in the Spacehab module, including when the Orbiter is docked at the Mir space station. The analyzer is scheduled to be launched again in May 1997 (STS-84) when it will be transferred to Mir. During both flights the analyzer will measure the quality of recycled and ground-supplied potable water on the space station. Samples will be archived for later return to the ground, where they will be analyzed for comparison to in-flight results. Water test samples of known composition, brought up with the analyzer, also will be used to test its performance in microgravity. Ground-based analyses of duplicates of those test samples will be conducted concurrently with the in-flight analyses.

Increasing fuel costs and the desire for reduced dependence on foreign oil has brought the diesel engine to the forefront of future medium-duty vehicle applications in the United States due to its higher thermal efficiency and superior durability. The main obstacle to the increased use of diesel engines in this platform is the upcoming extremely stringent, Tier 2 emission standard. In order to succeed, diesel vehicles must comply with emissions standards while maintaining their excellent fuel economy. The availability of technologies such as common rail fuel injection systems, low sulfur diesel fuel, NOX adsorber catalysts (NAC), and diesel particle filters (DPFs) allow the development of powertrain systems that have the potential to comply with these future requirements. In meeting the Tier 2 emissions standards, the heavy light-duty trucks (HLDTs) and medium-duty passenger vehicles (MDPVs) will face the greatest technological challenges. In support of this, the U.S.

Increasing fuel costs and the desire for reduced dependence on foreign oil has brought the diesel engine to the forefront of future medium-duty vehicle applications in the United States due to its higher thermal efficiency and superior durability. The main obstacle to the increased use of diesel engines in this platform is the upcoming extremely stringent, Tier 2 emission standard. In order to succeed, diesel vehicles must comply with emissions standards while maintaining their excellent fuel economy. The availability of technologies such as common rail fuel injection systems, low sulfur diesel fuel, NOX adsorber catalysts (NAC), and diesel particle filters (DPFs) allow the development of powertrain systems that have the potential to comply with these future requirements. In meeting the Tier 2 emissions standards, the heavy light-duty trucks (HLDTs) and medium-duty passenger vehicles (MDPVs) will face the greatest technological challenges. In support of this, the U.S.

Under city driving conditions, the powertrain represents one of the major vehicle exterior noise sources. Especially at idle and during full load acceleration, the oil pan contributes significantly to the overall powertrain sound emission. The engine oilpan can be a significant contributor to the powertrain radiated sound levels. Passive optimization measures, such as structural optimization and acoustic shielding, can be limited by e.g. light-weight design, package and thermal constraints. Therefore, the potential of the Active Structure Acoustic Control (ASAC) method for noise reduction was investigated within the EU-sponsored project InMAR. The method has proven to have significant noise reduction potential with respect to oil pan vibration induced noise. The paper reports on activities within the InMAR project with regard to a passenger car oil pan application of an ASAC system based on piezo-ceramic foil technology.

Absorption cooling using a lithium chloride/water heat pump can enable lightweight and effective thermal control for Extravehicular Activity (EVA) suits without venting water to the environment. The key components in the system are an absorber/radiator that rejects heat to space and a flexible evaporation cooling garment that absorbs heat from the crew member, This paper describes progress in the design, development, and testing of the absorber/radiator and evaporation cooling garment. New design concepts and fabrication approaches will significantly reduce the mass of the absorber/radiator. We have also identified materials and demonstrated fabrication approaches for production of a flexible evaporation cooling garment, Data from tests of the system's modular components have validated the design models and allowed predictions of the size and weight of a complete system.

Fleet managers need a tool to assist them in assessing their need to comply with EPAct and to provide them with the ability to obtain information that will allow them to make alternative fuel vehicle purchasing decisions. This paper will describe the Web-based tool that will inform a fleet manager, based on their geographic location, the type of fleet they own or operate, and the number and types of vehicles in their fleet, whether or not they need to meet the requirements of EPAct, and, if so, the percentage of new vehicle purchases needed to comply with the law. The tool provides detailed specifications on available OEM alternative fuel vehicles, including the purchase cost of the vehicles, fuel and fuel system characteristics, and incentives and rebates surrounding the purchase of each vehicle. The full set of federal, state, and local incentives is made available through the tool, as well as detailed access to refueling site and dealership locations.

Cummins Westport Inc. (CWI) released for production the latest version of its C8.3G natural gas engine, the C Gas Plus, in July 2001. This engine has increased ratings for horsepower and torque, a full-authority engine controller, wide tolerance to natural gas fuel (the minimum methane number is 65), and improved diagnostics capability. The C Gas Plus also meets the California Air Resources Board optional low-NOx (2.0 g/bhp-h) emission standard for automotive and urban buses. Two pre-production C Gas Plus engines were operated in a Viking Freight fleet for 12 months as part of the U.S. Department of Energy's Fuels Utilization Program. In-use exhaust emissions, fuel economy, and fuel cost were collected and compared with similar 1997 Cummins C8.3 diesel tractors. CWI and the West Virginia University developed an ad-hoc test cycle to simulate the Viking Freight fleet duty cycle from in-service data collected with data loggers.

The current test programmes have measured emissions from a heavy-duty bus engine installed on a test bench and also on a chassis dynamometer whilst running on a Diesel/water emulsion fuel. Testing was carried out over both steady state and transient test cycles. Emissions were also measured on the test bed from the engine fitted with both a Diesel particulate filter and an oxidation catalyst. Alongside the measurement of the regulated emissions, particle number distributions (by size) and total particle counts were also measured. Size selected particle counts were made over the transient tests and are compared between engine test and chassis dynamometer. This paper demonstrates the influence of the emulsion on the particle size distribution, the effects of after-treatment and lubricant on the particle size emissions of an engine running on an emulsion and also the influence of sampling conditions on the measurements recorded.

In this paper, data are presented showing how lubricant properties affect the heat flux, oil flow rates and temperatures within a turbocharged diesel passenger car engine. The oils tested cover a range of viscosities and base oil types. Mono-grades were used to remove the effect of shear thinning. The effect of viscosity modification was also examined. Lowest viscosity lubricants resulted in the lowest sump temperatures. More fuel was required to produce the same brake output from the engine with thicker oils. Engine oil heat rejection increased with viscosity, not just in absolute terms, but also as a fraction of the total heat loss. Viscosity does affect oil temperature through increased total heat from friction, and also through its effect on heat transfer. In addition, oil viscosity is itself dependent on operating temperature. Heat transfer theory suggests a relation between mass flow rate and heat transfer.

Since the mechanisms leading to cyclic combustion variabilities in direct injection gasoline engines are still poorly understood, advanced computational studies are necessary to be able to predict, analyze and optimize the complete engine process from aerodynamics to mixing, ignition, combustion and heat transfer. In this work the Scale-Adaptive Simulation (SAS) turbulence model is used in combination with a parameterized lagrangian spray model for the purpose of predicting transient in-cylinder cold flow, injection and mixture formation in a gasoline engine. An existing CFD model based on FLUENT v15.0 [1] has been extended with a spray description using the FLUENT Discrete Phase Model (DPM). This article will first discuss the validation of the in-cylinder cold flow model using experimental data measured within an optically accessible engine by High Speed Particle Image Velocimetry (HS-PIV).

The overall perception of a vehicle's quality is significantly influenced by its interior noise characteristics. Therefore, it is important to strike a balance between “pleasant” and “dynamic” sound that fits the customer requirements with respect to vehicle brand and class [1]. Typically, a significant share of the interior vehicle noise is transferred through structure-borne paths. Hence, the powertrain mounting system plays an important role in designing the interior noise. This paper describes an application of the method of vehicle interior noise simulation (VINS) to achieve a characteristic interior sound. This approach is based on separate measurements (or calculations) of excitations and transfer functions and subsequent calculation of the interior noise in the time domain.

The First Law of Thermodynamics has been applied to the analysis of the dynamometer performance of a 2.0 litre,115 PS, common rail, turbocharged, automotive diesel engine operating under steady state conditions. Validation of the method is presented with correlation between the input fuel power and summed loss terms shown to be better than 3%. The study was conducted over a matrix of engine speed-load sites and maps of the underlying trends and magnitudes are presented. Detailed analysis of the relative heat balance contributions at a range of loads at fixed engine, water pump, and oil pump speeds is also presented. The proportions of heat rejected to the different primary paths (i.e. brake, coolant, oil, charge cooler, exhaust, and external) were found to vary with engine speed and load. Also, friction power was found to vary principally as a function of engine speed with some small dependency on engine load.