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Effects of fuel cell material properties on water management were numerically investigated using Volume of Fluid (VOF) method in the FLUENT. The results show that the channel surface wettability is an important design variable for both serpentine and interdigitated flow channel configurations. In a serpentine air flow channel, hydrophilic surfaces could benefit the reactant transport to reaction sites by facilitating water transport along channel edges or on channel surfaces; however, the hydrophilic surfaces would also introduce significantly pressure drop as a penalty. For interdigitated air flow channel design, it is observable that liquid water exists only in the outlet channel; it is also observable that water distribution inside GDL is uneven due to the pressure distribution caused by interdigitated structure. An in-situ water measurement method, neutron imaging technique, was used to investigate the water behavior in a PEM fuel cell.

The objective of the paper is to characterize the diesel spray under the ambient conditions relevant for direct injection (D.I.) diesel engines. The particular emphasis is on the comparisons between laser measurements and predictions by empirical correlations and theoretical analyses. The ultraviolet-visible laser absorption-scattering (LAS) imaging technique is employed to quantitively determine the spray/mixture properties of the diesel spray injected by a hole-type injector, in terms of spray tip penetration and spatial concentration distributions of liquid and vapor phase. The structure of evaporating spray is obtained and analyzed. Based on the penetration correlations in the literature, a non-dimensional analysis of the spray tip penetration data is carried out. The results indicate that a self-similar state of the evaporating fuel spray is achieved.

The Reverse Braking Assist (RBA) feature is designed to automatically activate full braking in a backing vehicle. When this feature activates, a backing vehicle is suddenly stopped or may slide to a stop. During this process, an understanding of the driver's behavior may be useful in the design of an appropriate human-machine-interface (HMI) for the RBA. Several experimental studies were done to examine driver behavior in response to an unexpected and automatic braking event while backing [1]. Two of these studies are reported in this paper. A 7-passenger Crossover Utility Vehicle was fitted with a rear-view camera, a center-stack mounted LCD screen, and ancillary recording devices. In the first study, an object was suddenly placed in the path of a backing vehicle. The backing vehicle came to a sudden and complete stop. The visual image of the backing path on the LCD prominently showed that an obstacle was present in the backing path of the vehicle.

Diesel engine exhaust aftertreatment components, especially the diesel particulate filter (DPF), are subject to various modes of degradation over their lifetimes. One particular adverse effect on the DPF is the significant rise in pressure drop due to the accumulation of engine lubricant-derived ash which coats the inlet channel walls effectively decreasing the permeability of the filter. The decreased permeability due to ash in the DPF can result in increased filter pressure drop and decreased fuel economy. A unique two-step approach, consisting of experimental measurements and direct numerical simulations using ultra-high resolution 3D imaging data, has been utilized in this study to better understand the effects of ash accumulation on engine aftertreatment component functionality.

The Engine-Out Particulate Matter (EOPM) was collected from a spark ignition engine operating in steady state using a heated quartz fiber filter. The samples were weighted to obtain an EOPMindex and were analyzed using Scanning Electron Microscopy. The EOP Mindex was not sensitive to the engine rpm and load. When the mixture is very rich (air equivalence ratio λ less than ∼ 0.7), the EOPM comprise mostly of soot particles from fuel combustion. In the lean to slightly rich region (0.8 < λ < 1.2), however, the EOPM are dominated by particles derived from the lubrication oil.

The group-hole (GH) nozzle concept that uses two closely spaced micro-orifices to substitute the conventional single orifice has the potential to facilitate better fuel atomization and evaporation, consequently attenuate the soot emission formed in direct-injection (D.I.) diesel engines. Studies of quantitative mixture properties of the transient fuel spray injected by the group-hole nozzles were conducted in a constant volume chamber via the laser absorption-scattering (LAS) technique, in comparison with conventional single-hole nozzles. Specific areas investigated involved: the non-evaporating and the evaporating ambient conditions, the free spray and the spray impinging on a flat wall conditions. The particular emphasis was on the effect of one of key parameters, the interval between orifices, of the group-hole (SH) nozzle structure.

The presence of liquid fuel inside the engine cylinder is believed to be a strong contributor to the high levels of hydrocarbon emissions from spark ignition (SI) engines during the warm-up period. Quantifying and determining the fate of the liquid fuel that enters the cylinder is the first step in understanding the process of emissions formation. This work uses planar laser induced fluorescence (PLIF) to visualize the liquid fuel present in the cylinder. The fluorescing compounds in indolene, and mixtures of iso-octane with dopants of different boiling points (acetone and 3-pentanone) were used to trace the behavior of different volatility components. Images were taken of three different planes through the engine intersecting the intake valve region. A closed valve fuel injection strategy was used, as this is the strategy most commonly used in practice. Background subtraction and masking were both performed to reduce the effect of any spurious fluorescence.

Rapid Prototyping, Fabrication and Tooling is a process that blends a series of technologies (machines, tools, and methods) capable of generating physical objects directly from a CAD database. The process dramatically reduces the time spent during product development by allowing for fast visualization, verification, iteration, optimization, and fabrication of parts and tools. Many new techniques of tooling have been and are being developed by using rapid fabricated parts. These are having a dramatic impact on both timing and costs throughout the automotive industry. One area that these methods can be utilized to their full potential is motorsports. Of particular interest is the growing use of bridge tooling to provide first article through production intent parts that promote cost effective changes.

This paper proposes a novel algorithm. This algorithm is called Self-Organizing Fuzzy Neural Network (SOFNN). SOFNN revolutionizes how researchers apply control theories, image/signal processing on control systems and other applications. In general, SOFNN is an identification technique that automatically initiates, builds and fine-tunes the required network parameters. SOFNN evaluates required structures without predefined parameters or expressions regarding systems. SOFNN sets out to learn and configure a system's characteristics. Self-constructing and self-tuning features enable SOFNN to handle complex, non-linear, and time-varying systems with higher accuracy, making systems identification easier. SOFNN constructs and fine-tunes the system parameter through two phases. The two phases are the construction and the parameter-tuning phase. The two phases run concurrently allowing SOFNN to identify systems on-line.

The breakup and atomization processes of the pre-swirl spray, which is produced before the hollow-cone spray from a high-pressure swirl-type D.I. gasoline injector, were investigated under different ambient pressure conditions. The injector has a press-fitted swirl tip, in which six tangential slots giving the injecting fuel an angular momentum are perforated at an equal space interval. A microscopic imaging technique was applied to get the spatially high-resolution LIF tomograms of the pre-swirl spray. The sprays were illuminated by an Nd:YAG laser light sheet and imaged using a high resolution CCD camera, fixed with a micro lens and coupled with an optical low-pass filter. The droplet size and the individual droplet's velocity were obtained by applying the image processing and the particle tracking techniques, respectively.

Reduction of orifice diameter of nozzle is advantageous to the fuel atomization in a D.I. diesel engine. However, the diameter reduction is usually accompanied with decrease of spray tip penetration, thus worsening fuel spatial-distribution and fuel-air mixing. In this paper, a group-hole nozzle concept was proposed to solve the problem resulting from minimization of orifice diameter. Compared to the conventional multi-hole nozzle, group-hole nozzle has a series group of orifices, and each group consists of two micro-orifices with a small spatial interval and small angle. For examining the characteristics of the spray injected by the group-hole nozzle, the ultraviolet-visible laser absorption-scattering (LAS) imaging technique was adopted to determine vapor concentration and droplets density as well as other spray characteristics such as spray angle and penetration of both vapor and liquid phases.

The intent of this paper is to summarize the work of the V8 power plant intake manifold radiated noise study. In a particular V8 engine application, customer satisfaction feedback provided observations of existing unpleasant noise at the driver's ear. A comprehensive analysis of customer data indicated that a range from 500 to 800 Hz suggests a potential improvement in noise reduction at the driver's ear. In this study the noise source was determined using various accelerometers located throughout the valley of the engine and intake manifold. The overall surface velocity of the engine valley was ranked with respect to the overall surface velocity of the intake manifold. An intensity mapping technique was also used to determine the major component noise contribution. In order to validate the experimental findings, a series of analysis was also conducted. The analysis model included not only the plastic intake manifold, but also the whole powertrain.

Computer simulation of extravehicular activity (EVA) is increasingly being used in planning and training for EVA. A space suit model is an important, but often overlooked, component of an EVA simulation. Because of the inherent difficulties in collecting angle and torque data for space suit joints in realistic conditions, little data exists on the torques that a space suit’s wearer must provide in order to move in the space suit. A joint angle and torque database was compiled on the Extravehicular Maneuvering Unit (EMU), with a novel measurement technique that used both human test subjects and an instrumented robot. Using data collected in the experiment, a hysteresis modeling technique was used to predict EMU joint torques from joint angular positions. The hysteresis model was then applied to EVA operations by mapping out the reach and work envelopes for the EMU.

Experimental results of a diesel engine have shown that using split-injection can reduce the NOx and particulate emissions. For understanding the mechanism of emissions reduction, mixture formation in split-injection diesel sprays was characterized in the present paper. A dual-wavelength laser absorption-scattering (LAS) technique was developed by use of the second harmonic (532nm) and the fourth harmonic (266nm) of a pulsed Nd:YAG laser as the incident light and dimethylnaphthalene (DMN) as the test fuel. By applying this technique, imaging was made of DMN sprays injected into a high-temperature and high-pressure constant volume vessel by a single-hole nozzle incorporated in a common rail injection system for D.I. diesel engine. The line-of-sight optical thickness of both fuel vapor and droplets in the sprays was yielded from the sprays images.

Three-dimensional behaviors of direct injection (D.I.) gasoline sprays were investigated using 2-D and 3-D particle image velocimetry (PIV) techniques. The fuel was injected with a swirl type injector for D.I. gasoline engines into a constant volume chamber in which ambient pressure was varied from 0.1 to 0.4 MPa at room temperature. The spray was illuminated by a laser light sheet generated by a double-pulsed Nd:YAG laser (wave length: 532 nm) and the succeeding two tomograms of the spray were taken by a high-resolution CCD camera. The 2-D and 3-D velocity distributions of the droplet cloud in the spray were calculated from these tomograms by using the PIV technique. The effects of the swirl groove flows in the injector and the ambient pressure on the structural behavior of the droplet cloud in the spray were also examined.

Effects of split injection, with a relatively short time interval between the two sprays, on the spray development process, and the air entrainment into the spray, were investigated by using laser induced fluorescence and particle image velocimetry (LIF-PIV) techniques. The velocities of the spray and the ambient air were measured. The cumulative mass of the ambient air entrained into the spray was calculated by using the entrainment velocity normal to the spray boundary. The vortex structure of the spray, formed around the leading edge of the spray, showed a true rotating flow motion at low ambient pressures of 0.1 MPa, whereas at 0.4 MPa, it was not a true rotating flow, but a phenomenon of the small droplets separating from the leading edge of the spray and falling behind, due to air resistance. The development processes of the 2nd spray were considerably different from that of the 1st spray because the 2nd spray was injected into the flow fields formed by the 1st spray.

An early formation process of the spray, which was injected by a high-pressure swirl-type injector that is widely used in direct injection spark ignition (DISI) gasoline engines, was investigated through image analyzing techniques. The sprays were illuminated both by an Nd:YAG laser light sheet for getting the spray tomograms and by a tungsten lamp for getting the scattered back light shadow images of the sprays. The sprays were imaged by using a high-resolution CCD camera and a high-speed digital imaging system. The early development aspects of the spray were investigated in detail through the measurement of the tip penetration, cone angle and width of the early spray. At the start of injection, the liquid column emerges first, and it forms the “pre-swirl spray” without the swirl component. Following the liquid column, the liquid sheet emerges, however its radial velocity component is weak to form the complete hollow-cone spray. This spray changes into the “weak-swirl spray”.

A number of advancements have been made in the coulometric sulfur trace instrumental technique for the real-time measurement of engine oil economy. These advancements include modification of the coulometric cell to improve reliability and reproducibility. The instrument has been interfaced with a microcomputer for instrument control as well as data acquisition, storage, and analysis. Studies were undertaken which demonstrate sufficient sensitivity and linearity for determination of engine oil economy at levels better than 10,000 miles/quart. Applications to steady-state engine oil consumption mapping and to instantaneous oil consumption during transient engine cycling are described. These instruments are being produced by an outside supplier for use in various company locations in both the engine production and engine research environments.

Lean-burn technology is now being reviewed again in view of demands for higher efficiency and cleanness in internal combustion engines. The improvement of combustion using in-cylinder gas flow control is the fundamental technology for establishing lean-burn technology, but the great increase in main combustion velocity due to intensifying of turbulence causes a deterioration in performance such as increase in heat loss and N0x. Thus, it is desirable to improve combustion stability while suppressing the increase in main burn velocity as much as possible (1). It is expected that the fluid characteristics of the in-cylinder tumbling motion that the generated vortices during intake stroke breake down in end-half of compression stroke will satisfy the above requisition. This study is concerned with the effects of enhancing of tumble intensity on combustion in 4-valve S. I. engines.

For both notchback-type and fastback-type models, it has been found that critical geometries which increase the aerodynamic drag exist, and the time-averaged wake patterns basically consist of an arch vortex behind the rear window and trailing vortices in the wake. The unsteady characteristics of the wake seem to be directly related to aerodynamic drag. However, the unsteady characteristics of these wake patterns for notchback and fastback cars were not clear. The purpose of present paper is to clarify these phenomena. We try to analyze experimentally the unsteady characteristics by measuring the velocity fluctuations in the wake, the pressure fluctuations on the trunk deck and the drag-force fluctuations acting on the model. At the same time, the analysis of the numerical simulation was made by using the same numerical model as the experimental model. The computed flow visualization behind the rear window showed a fluctuating arch vortex.