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Presented in this paper is a brief review of momentum exchange theory for Jet Noise Suppression. “Experimental Results from Scale Model Tests” are included. These data exhibit peak to peak attenuation of 20 db along maximum exhaust noise azimuths at a nozzle pressure ratio of 3.1.

This paper describes the interrelated controls for automatic start sequencing, fuel scheduling, customer air delivery, and supervisory and protective systems as applied to the Curtiss-Wright CW657E “Jet-Air” Compressor. Model CW657E is capable of delivering 15,000 SCFM air at 85 psig (at 30°F and sea level pressure) and may be used in a diversity of manufacturing, processing, and industrial applications. A description of the control system and its operation in relation to compressor requirements, while furnishing air to feed distribution lines to air assisted water atomizing nozzles for snow making is reviewed as an example. Other models can deliver up to 30,000 SCFM with modified control systems, including pressure controls.

Driver state monitoring is a crucial technology for enhancing road safety and preventing human error-caused accidents in the era of autonomous vehicles. This paper presents CogniSafe, a comprehensive driver monitoring system that uses deep learning and computer vision methods to detect various types of driver distractions and fatigue. CogniSafe consists of four modules: Driver anomaly detection and classification: A novel two-phase network that proposes and recognizes driver anomalies, such as texting, drinking, and adjusting radios, using multimodal and multiview input. Gaze estimation: A video-based neural network that jointly learns head pose and gaze dynamics, achieving robust and efficient gaze estimation across different head poses. Eye state analysis: A multi-tasking CNN that encodes features from both eye and mouth regions, predicting the percentage of eye closure (PERCLOS) and the frequency of mouth opening (FOM).

The Swedish Biomimetics 3000's μMist® platform technology has been used to develop a radically new injection system. This prototype system, developed and characterized with support from Lotus, as part of Swedish Biomimetics 3000®'s V₂IO innovation accelerating model, delivers improved combustion efficiency through achieving exceptionally small droplets, at fuel rail pressures far less than conventional GDI systems and as low as PFI systems. The system gives the opportunity to prepare and deliver all of the fuel load for the engine while the intake valves are open and after the exhaust valves have closed, thereby offering the potential to use advanced charge scavenging techniques in PFI engines which have hitherto been restricted to direct-injection engines, and at a lower system cost than a GDI injection system.

Zero-offset in transducer output during airbag noise testing is often observed, but mostly ignored due to the lack of understanding of its causes and implications. In the field of high-g acceleration measurement, this phenomenon is well documented, and is referred to as zeroshift. Zero-offset occurs when a component in the measurement chain is exposed to some unexpected inputs which the component has not been designed to handle. These unexpected inputs can be mechanical, electrical, or optical. How the transducer reacts to such inputs and the amount of zero-offset produced depends on the sensing mechanism, material used, and the design of the component itself. This paper explores the causes of zero-offset from a general perspective, covering the entire measurement chain. Although much of the information and discussions are based on data obtained from acceleration measurement systems, the findings are applicable to other transducer types, such as pressure and acoustic measurements.

The thermal deflection associated with the conventional die heat treating procedure usually requires extra die grinding process to fine-tune the die surface. Due to the size of the production die, the grinding is time consuming and is not cost effective. The goal of the study is to develop a new die heat treating process utilizing the flexible laser heat treatment, which could serve the same purpose as the conventional die heat treating and avoid the thermal deflection. The unique look of the developed zebra pattern laser heat treating process is defined as the Zebra Line. The heat-treating parameters and processes were developed and calibrated to produce the laser heat treating on laboratory size dies, which were subjected to the die wear test in the laboratory condition. The USS HDGI 980 XG3TM steel was selected to be carried out on the developmental dies in the cyclic bend die wear test due to its high strength and coating characteristic.

Schlieren and shadowgraph imaging have been used for many years to identify refractive index gradients in various applications. For evaporating fuel sprays, these techniques can differentiate the boundary between spray regions and background ambient gases. Valuable information such as the penetration rate, spreading angle, spray structure, and spray pattern can be obtained using schlieren diagnostics. In this study, we present details of a z-type schlieren system setup and its application to port-fuel-injection gasoline sprays. The schlieren high-speed movies were used to obtain time histories of the spray penetration and spreading angle. Later, these global parameters were compared to specifications provided by the injector manufacturer. Also, diagnostic parameters such as the proportion of light cut-off at the focal point and the orientation of knife-edge (schlieren-stop) used to achieve the cut-off were examined.

Automotive clearcoats have many purposes, from providing a glossy finish to protecting the underlying paint layers from UV radiation. Yellowing of clearcoats is a natural phenomenon during weathering processes, as well as from extreme baking conditions, due to polymer degradation. However, occasionally yellowing may be caused by unexpected chemical reactions occurring in the clearcoat. These reactions may happen very quickly (within hours or days) or take years to manifest, as other chemicals migrate into the clearcoat. We have investigated one family of these unexpected reactions which occur with certain UV absorbers, as well as how to prevent the reactions from occurring. We found that certain benzotriazole UV absorbers react readily with some common metals, including copper and zinc, provided that the UV absorber is not in its excited state. The conformational change that occurs within the benzotriazole when it absorbs UV radiation effectively inhibits the reaction with metals.

Xenon (HID) technology is one of the mile-stones in developing process of car lighting. The first step was to combine this technology with free-form reflector technology. The result was a high performance dipped beam beam-pattern with three times more light output compared to a halogen system. The next step of improvement is “Bi-Xenon”. It makes sense to use the enormous light output of a Xenon light source for two light functions (Main beam and dipped beam) in a single pocket headlamp system. This leads to new lighting performance and design freedom in headlamp technology. In this paper the technological aspects of system realization will be described. New solutions in lighting strategy including modern actuators which handle optical elements to switch between two light functions had to be found.

Cavitation plays a significant role in high pressure diesel injectors. However, cavitation is difficult to measure under realistic conditions. X-ray phase contrast imaging has been used in the past to study the internal geometry of fuel injectors and the structure of diesel sprays. In this paper we extend the technique to make in-situ measurements of cavitation inside unmodified diesel injectors at pressures of up to 1200 bar through the steel nozzle wall. A cerium contrast agent was added to a diesel surrogate, and the changes in x-ray intensity caused by changes in the fluid density due to cavitation were measured. Without the need to modify the injector for optical access, realistic injection and ambient pressures can be obtained and the effects of realistic nozzle geometries can be investigated. A range of single and multi-hole injectors were studied, both sharp-edged and hydro-ground. Cavitation was observed to increase with higher rail pressures.

The salient features of modern gasoline direct injection include cavitation, flash boiling, and plume/plume interaction, depending on the operating conditions. These complex phenomena make the prediction of the spray behavior particularly difficult. The present investigation combines mass-based experimental diagnostics with an advanced, in-house modeling capability in order to provide a multi-faceted study of the Engine Combustion Network’s Spray G injector. First, x-ray tomography is used to distinguish the actual injector geometry from the nominal geometry used in past works. The actual geometry is used as the basis of multidimensional CFD simulations which are compared to x-ray radiography measurements for validation under cold conditions. The influence of nozzle diameter and corner radius are of particular interest. Next, the model is used to simulate flash-boiling conditions, in order to understand how the cold flow behavior corresponds to flashing performance.

A quantitative and time-resolved technique has been developed to probe the fuel distribution very near the nozzle of a high-pressure diesel injector. This technique uses the absorption of synchrotron x-rays to measure the fuel mass with good time and position resolution. The penetrating power of x-rays allows measurements that are difficult with other techniques, such as quantitative measurements of the mass and penetration measurements of the trailing edge of the spray. Line-of-sight measurements were used to determine the fuel density as a function of time. The high time resolution and quantitative nature of the measurement also permit an accurate measure of the instantaneous mass flow rate through the nozzle.

In order to analyze the effects of nozzle geometry on the structure of fuel sprays, quantitative x-ray measurements have been performed on sprays from nozzles with different degrees of hydro-grinding. The two nozzles were measured at injection pressures of 500 and 1000 bar in an ambient environment of 1 bar nitrogen gas. Time-resolved x-radiography was used to measure the two-dimensional mass distributions of the spray as a function of time for the entire spray event. The initial mass flow through the nozzles was determined from the x-ray data, the nozzles showed no appreciable differences in the early part of the injection event. The transverse mass distributions were fit with Gaussian curves, and the assumption of axisymmetry was used to calculate the volume fraction of each spray. It was observed that the nozzle which had undergone extensive hydro-grinding generated a more dense spray than the sharp-edged nozzle at an injection pressure of 1000 bar.

Workspace is an important function for human factors analysis and is widely applied in product design, manufacturing, and ergonomics evaluations. This paper presents the workspace analysis and visualization for Santos™ upper extremity, a new virtual human with over 100 DOFs that is highly realistic in terms of appearance, behavior, and movement. Jacobian Rank deficiency method is implemented to determine the singular surfaces. The joint limits are considered in this formulation; three types of singularities are analyzed. This closed-form formulation can be extended to numerous different scenarios such as different percentiles, age groups, or segments of body. A realtime scheme is used to build the workspace library for Santos™ that will study the boundary surfaces off-line and apply them to Santos™ in the virtual environment (Virtools®). To visualize the workspace, we develop a user interface to generate the cross section of the reach envelope with a plane.

With COSMOsim, OTSL is looking to better virtually recreate diverse driving conditions to enable safe and accurate verifications at a point when autonomous driving continues to move toward practical use around the world.

Integration of a driver monitor system (DMS) in a head-up display (HUD) gives the monitor camera a continuous view of the driver’s face, since the driver always faces the road ahead. However, with both infrared (IR) illuminator and IR camera packaged in the HUD, reflectivity of the windshield is important at IR wavelengths used by the camera. Not only is windshield IR reflectivity important for a clear camera image of the driver’s face, but increasing windshield reflectivity also decreases the effect of ambient sunlight on the camera image of the driver’s face. We describe a method to measure windshield reflectivity, both for the 940 nm band used by a DMS, and for visible light for the HUD. The measurement method uses a fiber-optic spectrometer, two collimating lenses, and a method to compensate for sample tilt. The lenses are mounted on a stage that adjusts the height above the sample.

In this paper we investigate the influence of the aerodynamics of the vehicle on the performance of the washer fluid spray. A planar windshield block model with various windshield angles, as well as a “generic” passenger car shape with a fixed windshield angle, is used for the present studies. CFD simulations of the flow field and the spray trajectories are undertaken in this study. The effect of windshield angles, nozzle location and crosswind on the spray performance is presented in this paper. For very large windshield angles of around 60° (measured from the vertical plane), there is no flow separation in the hood-windshield intersection region and the spray trajectory is significantly affected by the airstream for all nozzle locations.

Wipe quality of wiper systems is influenced not only by the definition of the wiper system, but also by the shape of the glass. In order to optimize the overall performance of the system, Valeo Wiper Systems has developed an optimization algorithm, which is based on geometrical criteria. The multi-criteria objective not only considers wipe quality but also constraints by glass feasibility and respect of optical standards. As the direct derivation of the objective functions is not available, a neural network approximation is used at the place of the real function. A neural network with several outputs enables the engineer to include his knowledge in the optimization loop by changing disciplinary weights.

Some undesirable optical effects that arise from design of windshields-such as double images, distortion, astigmatism, and differential deviation of line of sight-are discussed. The reasons for, and methods of eliminating, “ghost” images are reviewed. Curvature and tilt angle are principal design parameters available for control of ghost images. Another factor involved in double images is wedge. Several illustrations show how cylindrically curved auto glass produces astigmatism. Glass parameters which produce astigmatism of 1/4 diopter are rather severe, however. The amount of differential deviation depends on angle of view, and on curvature, thickness, and refractive index of the glass. It is desirable to minimize differential deviation since it may result in error in making quick assessments of traffic situations.

Through this work, Wind River and Airbiquity look to enable secure and intelligent software updates and data management for these vehicles through over-the-air (OTA) programming technology. The work may also lead to similar solutions for traditional aerospace and unmanned aircraft system (UAS) industries.