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As fuel economy becomes increasingly important in all markets, complete engine system optimization is required to meet future standards. In many applications, it is difficult to realize the optimum coolant or lubricant pump without first evaluating different sets of engine hardware and iterating on the flow and pressure requirements. For this study, a Heavy Duty Diesel (HDD) engine was run in a dynamometer test cell with full variability of the production coolant and lubricant pumps. Two test stands were developed to allow the engine coolant and lubricant pumps to be fully mapped during engine operation. The pumps were removed from the engine and powered by electric motors with inline torque meters. Each fluid circuit was instrumented with volume flow meters and pressure measurements at multiple locations. After development of the pump stands, research efforts were focused on hardware changes to reduce coolant and lubricant flow requirements of the HDD engine.

The Scuderi engine is a split cycle design that divides the four strokes of a conventional combustion cycle over two paired cylinders, one intake/compression cylinder and one power/exhaust cylinder, connected by a crossover port. This configuration provides potential benefits to the combustion process, as well as presenting some challenges. A Miller cycle configuration of the engine is made possible by turbocharging with a downsized compressor cylinder and has been modeled in 1-dimensional cycle simulation software.

Fossil fuel consumption is a significant factor in terms of both economic and environ-mental impact of on- and off-highway systems. Because fuel consumption can be directly tied to equipment efficiency, gains in efficiency can lead to reduction in operating costs as well as conservation of nonrenewable resources. Fluid performance has a direct effect on the efficiency of a hydraulic system. A procedure has been developed for measuring a fluid's effect on the degree to which mechanical power is efficiently converted to hydraulic power in pumps typical of off-highway applications.

This paper will describe the fuel economy benefits that can be obtained when traditionally engine-driven accessories such as water pumps, oil pumps, power steering pumps, radiator cooling fans and air conditioning compressors are decoupled from the engine and are remotely driven and controlled. Simulation results for different vehicle configurations such as heavy duty trucks operated over urban and highway driving cycles and light duty vehicles such as mini vans will be presented. These results will quantify the heavy dependence of fuel economy benefits associated with different types of driving cycles.

When technologies are traded for incorporation into vehicle systems to support a specific mission scenario, they are often assessed in terms of “Technology Readiness Level” (TRL). TRL is based on three major categories of Core Technology Components, Ancillary Hardware and System Maturity, and Control and Control Integration. This paper describes the Technology Readiness Level assessment of the Carbon Dioxide Reduction Assembly (CRA) for use on the International Space Station. A team comprising of the NASA Johnson Space Center, Marshall Space Flight Center, Southwest Research Institute and Hamilton Sundstrand Space Systems International have been working on various aspects of the CRA to bring its TRL from 4/5 up to 6. This paper describes the work currently being done in the three major categories. Specific details are given on technology development of the Core Technology Components including the reactor, phase separator and CO2 compressor.

An analysis model has been developed for analyzing/optimizing the integration of a carbon dioxide removal assembly (CDRA), CO2 compressor, accumulator, and Sabatier CO2 reduction assembly. The integrated model can be used in optimizing compressor sizes, compressor operation logic, water generation from Sabatier, utilization of CO2 from crew metabolic output, and utilization of H2 from oxygen generation assembly. Tests to validate CO2 desorption, recovery, and compression had been conducted in 2002-2003 using CDRA/Simulation compressor set-up at NASA Marshall Space Flight Center (MSFC). An analysis of test data has validated CO2 desorption rate profile, CO2 compressor performance, CO2 recovery and CO2 vacuum vent in the CDRA model. Analysis / optimization of the compressor size and the compressor operation logic for an integrated closed air revitalization system is currently being conducted

The electrification of accessories using a fuel cell as an auxiliary power unit reduces the load on the engine and provides opportunities to increase propulsion performance or reduce engine displacement. The SunLine™ Class 8 tractor electric accessory integration project is a United States Army National Automotive Center (NAC™) initiative in partnership with Cummins Inc., Dynetek™ Industries Ltd., General Dynamics C4 Systems, Acumentrics™ Corporation, Michelin North America, Engineered Machine Products (EMP™), Peterbilt™ Motors Company, Modine™ Manufacturing and Masterflux™. Southwest Research Institute is the technical integration contractor to SunLine™ Services Group. In this paper the SunLine™ tractor electric Air Conditioning (AC) system is described and the installation of components on the tractor is illustrated. The AC system has been designed to retrofit into an existing automotive system and every effort was made to maintain OEM components whenever modifications were made.

Two different laboratory fuel-injection-pump durability-tests were conducted with four advanced technology test fuels. The first test used a relatively low pressure rotary, opposed piston fuel injection pump similar to those used on some current North American engines. The second test used a relatively high pressure common rail injection pump such as those used currently on some European engines. The tests were scheduled to operate for 500 hours under severe load conditions. It can be concluded that the common-rail, high-pressure fuel pump is more sensitive to the advanced fuels than is the rotary pump in this severe duty-cycle test. Although the laboratory high frequency reciprocating rig (HFRR) tests were able to distinguish between those fuels that contained lubricity additives and those that did not, there was little correlation with pump durability results.

The current operation of the International Space Station (ISS) calls for the oxygen used by the occupants to be vented overboard in the form of CO2, after the CO2 is scrubbed from the cabin air. Likewise, H2 produced via electrolysis in the oxygen generator is also vented. NASA is investigating the use of the Sabatier process to combine these two product streams to form water and methane. The water is then used in the oxygen generator, thereby conserving this valuable resource. One of the technical challenges to developing the Sabatier reactor is transferring CO2 from the Carbon Dioxide Removal Assembly (CDRA) to the Sabatier reactor at the required rate, even though the CDRA and the Sabatier reactor operate on different schedules. One possible way to transfer and store CO2 is to use a mechanical compressor and a storage tank.

A number of laboratory-scale test methods are available to predict the effects of fuel lubricity on injection system wear. Anecdotal evidence exists to indicate that these methods produce poor correlation with pump wear, particularly for fuels that contain lubricity additives. The issue is further complicated by variations in the lubricity requirements of full-scale equipment and the test methodologies used to evaluate the pumps. However, the cost of performing full-scale equipment testing severely limits the quantity of data available for validation of the laboratory procedures at any single location. In the present study, the technical literature was reviewed and all previously published data was combined to form a single database of 175 pump stand results. This volume of data allows far more accurate statistical analysis than is possible with tests performed at a single location. The results indicate differences in the effectiveness of the standardized laboratory-scale methods.

This paper will overview current production manual, automatic, and continuously variable transmission (CVT) efficiencies and efficiency variations across the industry. For automatic transmissions, efficiencies associated with the pump and the gearbox components will be highlighted along with areas for improvements. Efficiencies associated with various types of pumps such as internal-external, gerotor, hypocycloidal, and variable displacement will be compared. For CVT's a comparison of efficiencies for belt type and toroidal types will be provided, along with an examination of external-external and variable displacement type ball pumps.

A cooperative research and development program was organized to determine the critical particle size of abrasive debris that will cause significant wear in rotary injection fuel pumps. Various double-cut test dusts ranging from 0-5 to 10-20 μm were evaluated to determine which caused the pumps to fail. With the exception of the 0-5-μm test dust, all other test dust ranges evaluated caused failure in the rotary injection pumps. After preliminary testing, it was agreed that the 4-8-μm test dust would be used for further testing. Analysis revealed that the critical particle size causing significant wear is 6-7 μm. This is a smaller abrasive particle size than reported in previously published literature. A rotary injection pump evaluation methodology was developed. During actual operation, the fuel injection process creates a shock wave that propagates back up the fuel line to the fuel filter.

System contamination caused by contaminates or small particles built-in, self-generated, or inhaled from environment presents severe problems. The problems include but are not limited to the malfunctioning of valves, pumps, seals and injectors or lock-up of these components; increased wear of bearings, piston rings, and other friction components; and degradated machine performance. In general, system contamination changes a deterministic system into a stochastic system and shortens machinery service life. In this paper, these contamination problems are discussed in categories and associated analysis, testing and computer modeling methodologies are also discussed.

Increased concern for improving fuel mileage in today's vehicles has focused attention on powertrain component efficiencies. Currently, no efficiency standards exist for automatic transmissions but, uniform testing procedures do exist. Consequently, vehicle and transmission manufacturers have no basis for comparing transmission-to-transmission performance. In addition, manufacturers have no design targets from which to critique their product. This paper addresses this issue by developing an overall transmission efficiency rating. This rating is based upon average transmission operational torques and speeds, the percent time of operation in each gear for a representative duty cycle, and representative efficiencies at these conditions based on test data obtained from a cross section of current production transmissions.

The pumping system used in a step ratio automatic transmission can consume up to 20% of the total power required to operate a typical automotive transmission through the EPA city cycle. As such, it represents an area manufacturers have focused their efforts towards in their quest to obtain improved transmission efficiency. This paper will discuss the history of automatic transmission pumps that develop up to 300 psi along with a description of the factors used to size pumps and establish pump flow requirements. The various types of pumps used in current automatic transmissions will be described with a discussion of their characteristics including a comparison based upon observations of their performance. Specific attention will be focused on comparing the volumetric efficiency, mechanical efficiency, overall efficiency, pumping torque and discharge flow.

Progress on the development of active suspension for improving mobility of rough terrain vehicles is being hindered by the potentially high energy requirements. A unique regenerative active suspension system has been conceived and is being developed to provide active suspension with very low energy requirements. Regenerative active suspension consists of multiple variable displacement pumps, each controlling flow to and from hydro-pneumatic struts to control a vehicle's low frequency body motions. When fluid is returned from a strut to a pump, energy is recovered or “regenerated” so that the total energy requirement is very low. This paper presents the results of a study showing the potential of the regenerative active suspension system to improve vehicle control and ride comfort of rough terrain vehicles enhancing mobility while requiring very little additional energy.

This paper is the second of two that describe the effects of low-lubricity fuels on diesel injection pump performance. The first paper describes the primary failure mechanisms and wear processes in a number of failed pumps removed from both military and civilian vehicles that had been operated on Jet A-1 and diesel fuels. However, the multitude of unregulated parameters in practical operation renders quantitative comparison between different fuels and pump combinations impractical. This paper describes the degradation in pump performance and the wear processes associated with fuels of varying lubricity in the well-defined environment of a pump test stand. The test methodology concentrates on those areas previously demonstrated to be most susceptible to wear. The results indicate that pump durability is reduced by highly refined low-viscosity fuels, but may be successfully counteracted by either improved metallurgy or lubricity additives.

The U.S. Department of Defense has adopted a concept in which a single fuel will be used on the battlefield; diesel fuel will be replaced by JP-8/JP-5/Jet A-1 in compression ignition engines, thereby decreasing the fuel logistics burden. JP-8 fuel has successfully undergone extensive testing in both the laboratory and in field trials. However, increased failure rates for fuel-lubricated rotary injection pump components operating on Jet A-1 aviation turbine fuel were reported during Operation Desert Shield. This paper is the first of two and describes the disassembly and failure analysis of twelve rotary fuel injection pumps that operated on Jet A-1. Also disassembled as a baseline for comparison were three additional pumps from civilian vehicles that had operated on commercial diesel. Each of the pumps had a unique service history, making quantitative comparison difficult.

Active automotive suspension systems have been under development for a number of years with recent introductions of various versions. A suspension system can be considered “active” when an outside power source is used to alter its characteristics, and these systems can be placed into one of three (3) different categories: semi-active damping, fully active, and low frequency active. A regenerative pump concept can minimize the power requirement for the low frequency active system. It utilizes four (4) independent variable displacement pump/motor combinations on a common shaft to actuate each individual suspension unit. This paper overviews the system configuration, describes the power and energy-saving features of the system, and discusses possible pump configurations and control strategies.

This paper describes the development of a CVS compatible sampling system for automotive sulfate emissions. The design resulted from a consensus of ideas from EPA and industry. The system can be used with either a positive displacement pump or critical flow venturi CVS. A mist generator was developed to quantitatively inject sulfuric acid into the tunnel. While sulfate losses were acceptable using the mist generator, with actual automotive exhaust sulfate losses were much higher. The reasons for these losses were investigated. Sulfate losses in the tubing between the car and sulfate tunnel were also investigated.