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In a recent study, quantitative measurements were presented of in-cylinder spatial distributions of mixture equivalence ratio in a single-cylinder light-duty optical diesel engine, operated with a non-reactive mixture at conditions similar to an early injection low-temperature combustion mode. In the experiments a planar laser-induced fluorescence (PLIF) methodology was used to obtain local mixture equivalence ratio values based on a diesel fuel surrogate (75% n-heptane, 25% iso-octane), with a small fraction of toluene as fluorescing tracer (0.5% by mass). Significant changes in the mixture's structure and composition at the walls were observed due to increased charge motion at high swirl and injection pressure levels. This suggested a non-negligible impact on wall heat transfer and, ultimately, on efficiency and engine-out emissions.

A system was developed which provides nutrients and water to plants while maintaining good aeration at the roots and preventing water from escaping in reduced gravity. The nutrient solution is circulated through porous tubes under negative pressure and moves through the tube wall via capillary forces into the rooting matrix, establishing a non-saturated condition in the root zone. Tests using prototypes of the porous tube water and nutrient delivery system indicate that plant productivity in this system is equivalent to standard soil and solution culture growing procedures. The system has functioned successfully in short-term microgravity during parabolic flight tests and will be flown on the space shuttle. Plants are one of the components of a bioregenerative life support system required for long duration space missions.

The flow through diesel fuel injector nozzles is important because of the effects on the spray and the atomization process. Modeling this nozzle flow is complicated by the presence of cavitation inside the nozzles. This investigation uses a two-dimensional, two-phase, transient model of cavitating nozzle flow to observe the individual effects of several nozzle parameters. The injection pressure is varied, as well as several geometric parameters. Results are presented for a range of rounded inlets, from r/D of 1/40 to 1/4. Similarly, results for a range of L/D from 2 to 8 are presented. Finally, the angle of the corner is varied from 50° to 150°. An axisymmetric injector tip is also simulated in order to observe the effects of upstream geometry on the nozzle flow. The injector tip calculations show that the upstream geometry has a small influence on the nozzle flow. The results demonstrate the model's ability to predict cavitating nozzle flow in several different geometries.

An engine cycle simulation code with detailed chemical kinetics has been developed to study Homogeneous Charge Compression Ignition (HCCI) combustion with hydrogen as the fuel. In order to attain adequate combustion duration, resulting from the self-accelerating nature of the chemical reaction, fuel and temperature inhomogeneities have been brought to the calculation by considering the combustion chamber to have various temperature and fuel distributions. Calculations have been done under various conditions including both perfectly homogeneous and inhomogeneous cases, changing the degree of inhomogeneity. The results show that intake gas temperature is more dominant on ignition timing of HCCI than equivalence ratio and that there is a possibility to control HCCI by introducing appropriate temperature inhomogeneity to in-cylinder mixture.

The objective of this study was to investigate the effects of fuel viscosity and the effects of nozzle inlet configuration on the characteristics of high injection pressure sprays. Three different viscosity fuels were used to reveal the effects of viscosity on the spray characteristics. The effects of nozzle inlet configuration on spray characteristics were studied using two mini-sac six-hole nozzles with different inlet configurations. A common rail injection system was used to introduce the spray at 90 MPa injection pressure into a constant volume chamber pressurized with argon gas. The information on high pressure transient sprays was captured by a high speed movie camera synchronized with a pulsed copper vapor laser. The images were analyzed to obtain the spray characteristics which include spray tip penetration, spray cone angle at two different regions, and overall spray Sauter Mean Diameter (SMD).

A transport equation residual model incorporating refined G-equation and detailed chemical kinetics combustion models has been developed and implemented in the ERC KIVA-3V release2 code for Gasoline Direct Injection (GDI) engine simulations for better predictions of flame propagation. In the transport equation residual model a fictitious species concept is introduced to account for the residual gases in the cylinder, which have a great effect on the laminar flame speed. The residual gases include CO2, H2O and N2 remaining from the previous engine cycle or introduced using EGR. This pseudo species is described by a transport equation. The transport equation residual model differentiates between CO2 and H2O from the previous engine cycle or EGR and that which is from the combustion products of the current engine cycle.

Farm workers experience a very high incidence of injuries leading to physical and cognitive (strokes, TBI) disabilities. Since 1991, the AgrAbility Project 2 and its staff have provided direct assistance and education to many U.S. farmers and farm workers. If farmers, ranchers or farm workers who become disabled continue to be employed in agriculture, often their agricultural operation must be modified and/or agricultural machinery must be modified or adaptive equipment purchased to meet their new needs. Some common tractor modifications include operator lifts, hand controls, added/modified steps and handrails, automated hitches, and custom seating. Some modifications are commercially available but others are done on an individual need basis. AgrAbility staff would welcome the opportunity to work closer with farm equipment manufacturers to create modifications that would make farming and ranching easier and safer for all.

This paper presents some experimental results of air velocity measurements near high pressure diesel sprays. The measurements were made using a moderately high pressure (90 MPa) common rail injector in a pressurized spray chamber. The chamber was operated at ambient temperature (25°C) and was pressurized with Argon to produce a chamber gas density of about 27 kg/m3, similar to densities found in a large turbocharged diesel near TDC. The gas phase was tagged using water droplets doped with Stilbene 420, with an estimated droplet size of 18 μm. The atomized water-Stilbene droplets were illuminated with the third harmonic of a pair of Nd:YAG lasers which caused the Stilbene to fluoresce at about 420 nm. To reduce the competing fluorescence from the injected fuel, the injector was fueled with Jet-A fuel. Using the two lasers, double exposures of the small droplets were recorded on film. The laser pulse lengths were about 6 ns, and typical times between pulses were 100 μs.

Airflow characteristics surrounding evaporating transient diesel sprays inside a constant volume chamber under temperatures around 1100 K were investigated using a 6-hole injector and a single-hole injector. Particle Image Velocimetry (PIV) was used to measure the gas velocities surrounding a spray plume as a function of space and time. A conical control surface surrounding the spray plume was chosen as a representative side entrainment surface. The normal velocities crossing the control surface toward the spray plume for single-hole injection sprays were higher than those of 6-hole injection sprays. The velocities tangential to the control surface toward the injector tip for the single-hole injection sprays were lower than those of 6-hole injection sprays. An abrupt increase in tangential velocities near the chamber wall suggests that the recirculation of surrounding gas was accelerated by the spray wall impingement, both for non-evaporating and evaporating sprays.

An experimental and numerical characterization has been conducted of a high-pressure common rail diesel fuel injection system. The experimental study was performed using a common rail system with the capability of producing multiple injections within a single cycle. The injector used in the experiments had a single guided multi-hole nozzle tip. The diesel sprays were injected into a pressurized chamber with optical access at ambient temperature. The gas density in the chamber was representative of the density in an HSDI diesel engine at the time of injection. Single, pilot, and multiple injection cases were studied at different rail pressures and injection durations. Images of the transient sprays were obtained with a high-speed digital camera. From these images spray tip penetration and cone angles were obtained directly. Also spray droplet sizes were derived from the images using a light extinction method (LEM).

The causes of injuries suffered by drivers in “small-overlap frontal crashes” (SOFC) were examined. These crashes were defined as ones in which vehicles are loaded outside their longitudinal side members. SOFC accident data sets stored in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database were investigated. Percentages of cases sustaining injury to each body region of drivers were calculated, and the differences between the percentages of injury by body region were examined. To investigate the injury mechanisms, SOFC tests with two types of rigid barrier were then conducted. Injury values in each body region were analyzed to validate the reproducibility of SOFC test as a relevant test.

In-cylinder thermal barrier coatings (TBCs) have the capability to reduce fuel consumption by reducing wall heat transfer and to increase exhaust enthalpy. Low thermal conductivity, low volumetric heat capacity thermal barrier coatings tend to reduce the gas-wall temperature difference, the driving potential for heat transfer from the gas to the combustion chamber surfaces. This paper presents a coupling between an analytical methodology for multi-layer coated wall surface temperature prediction with a fully calibrated production model in a commercial system-level simulation software package (GT-Power). The wall surface temperature at each time step was calculated efficiently by convolving the engine wall response function with the time-varying surface boundary condition, i. e., in-cylinder heat flux and coolant temperature. This tool allows the wall to be treated either as spatially uniform with one set of properties, or with independent head/piston/liner components.

Airflow characteristics surrounding non-evaporating transient diesel sprays were investigated using a 6-hole injector. Particle Image Velocimetry (PIV) was used to measure the gas velocities surrounding a spray plume as a function of space and time. A hydraulically actuated, electronically controlled unit injector (HEUI) system was used to supply the fuel into a pressurized constant volume chamber at room temperature. The chamber gas densities in this study were 10 kg/m3, 20 kg/m3 and 30 kg/m3. The injection pressure was 96.5 MPa. Two frequency doubled (532 nm) Nd:YAG lasers were used to create coincident laser sheets to illuminate the test section at two instances after start of injection (ASI). The double exposed images of sprays and Al2O3 seed particles were developed and velocity vectors of the gas surrounding the transient diesel sprays were obtained using a numerical autocorrelation PIV method.

The combined impacts of engine speed and fuel reactivity on energy-assisted compression-ignition (EACI) combustion using a commercial off-the-shelf (COTS) ceramic glow plug for low-load operation werexxz investigated. The COTS glow plug, used as the ignition assistant (IA), was overdriven beyond its conventional operation range. Engine speed was varied from 1200 RPM to 2100 RPM. Three fuel blends consisting of a jet-A fuel with military additives (F24) and a low cetane number alcohol-to-jet (ATJ) sustainable aviation fuel (SAF) were tested with cetane numbers (CN) of 25.9, 35.5, and 48.5. The ranges of engine speed and fuel cetane numbers studied are significantly larger than those in previous studies of EACI or glow-plug assisted combustion, and the simultaneous variation of engine speed and fuel reactivity are unique to this work. For each speed and fuel, a single-injection of fixed mass was used and the start of injection (SOI) was swept for each IA power.

Fundamental simulations using DNS type procedures were used to investigate the ignition, combustion characteristics and the lift-off trends of a spatially evolving turbulent liquid fuel jet. In particular, the spatially evolving n-Heptane spray injected in a two-dimensional rectangular domain with an engine like environment was investigated. The computational results were compared to the experimental observations from an optical engine as reported in the literature. It was found that an initial fuel rich combustion downstream of the spray tip is followed by diffusion combustion. Investigations were also made to understand the effects of injection velocity, ambient temperature and the droplet radius on the lift-off length. For each of these parameters three different values in a given range were chosen. For both injection velocity and droplet radius, an increase resulted in a near linear increase in the lift-off length.

The adaptation to changes in human operator dynamics and changes in working environment dynamics can be an important issue in designing high performance telerobotic systems. This paper describes an approach to force control in telerobotic hand systems in which model reference adaptive control techniques are used to adapt to changes in human operator and working environment dynamics. The techniques have been applied to force-reflective control of a single degree-of-freedom telerobotic gripper system at Wisconsin Center for Space Automation and Robotics (WCSAR). This adaptive gripping system is described in the paper along with results of experiments with human subjects in which the performance of the adaptive system was analysed and compared to the performance of a conventional non-adaptive system. These experiments emphasized adaptation to changes in compliance of gripped objects and adaptation to the on-set of human operator fatigue.

An experimental study was conducted using the dumping technique (total cylinder sampling) to produce cylinder mass-averaged nitric oxide histories. Data were taken using a four stroke diesel research engine employing a quiescent chamber, high pressure direct injection fuel system, and simulated turbocharging. Two fuels were used to determine fuel cetane number effects. Two loads were run, one at an equivalence ratio of 0.5 and the other at a ratio of 0.3. The engine speed was held constant at 1500 rpm. Under the turbocharged and retarded timing conditions of this study, nitric oxide was produced up to the point of about 85% mass burned. Two different models were used to simulate the engine run conditions: the phenomenological Hiroyasu spray-combustion model, and the three dimensional, U.W.-ERC modified KIVA-II computational fluid dynamic code. Both of the models predicted the correct nitric oxide trend.

The University of Wisconsin - Madison Hybrid Vehicle Team has designed, fabricated, tested and optimized a four-wheel drive, charge sustaining, split-parallel hybrid-electric crossover vehicle for entry into the 2006 Challenge X competition. This multi-year project is based on a 2005 Chevrolet Equinox platform. Trade-offs in fuel economy, greenhouse gas impact (GHGI), acceleration, component packaging and consumer acceptability were weighed to establish Wisconsin's Vehicle Technical Specifications (VTS). Wisconsin's Equinox, nicknamed the Moovada, utilizes a General Motors (GM) 110 kW 1.9 L CIDI engine coupled to GM's 6-speed F40 transmission. The rear axle is powered by a 65 kW Ballard induction motor/gearbox powered from a 44-module (317 volts nominal) Johnson Controls Inc., nickel-metal hydride hybrid battery pack. It includes a newly developed proprietary battery management algorithm which broadcasts the battery's state of charge onto the CAN network.

Using a low-speed high-torque (LSHT) pump/motor to provide the speed range and torque for a hydrostatic automobile offers a number of advantages over using a high-speed low-torque pump/motor, combined with a gear reducer. However, there appear to be no LSHT units commercially available that have true variable displacement capability. Because of this void, a variable displacement pump/motor has been designed and built that could provide a direct drive for each wheel of a hydrostatic automobile. The unit uses some components such as the cylinder block, piston and modified rotating case from a commercially available radial piston pump/motor. Initial preliminary testing of the pump/motor indicates that it has good efficiency and performance characteristics, and, with further development should be very attractive for automotive use. This paper focuses on the design and kinematics of the device.

An investigation of several diesel injector nozzles that produced different engine emissions performance was performed. The nozzle styles used were two VCO type nozzles that were manufactured using two different techniques, and two mini-sac nozzles that provided comparison. Fired experiments were conducted on a Detroit Diesel Series 50 engine. Optical access was obtained by substituting a sapphire window for one exhaust valve. Under high speed, high load, retarded injection timing conditions, it was discovered that each nozzle produced different specific soot and NOx emissions. High-speed film images were obtained. It was discovered that the temperature and KL factor results from the 2-color optical pyrometry showed significant differences between the nozzles. The authors propose the possibility that differences in air entrainment, caused by potential differences in CD due to surface finish, may contribute to the variance in emissions performance.