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White Paper

REDUCING DOWNTIME THROUGH THE USE OF PREDICTIVE ANALYTICS AND TECHNICAL TRAINING ADVANCEMENTS

2018-01-05
WP-0007
The exponential increase in the number of aircraft and air travelers has triggered new innovations aimed to make airline services more reliable and consumer friendly. Quick and efficient maintenance actions with minimum downtime are the need of the hour. Another major challenge is ensuring maintenance personnel are trained effectively; technology like augmented reality and Virtual Maintenance Trainers (VMTs) may provide safe and efficient training in lieu of live, instructor-led arrangements. And while traditional User/Maintenance Manuals provide useful information when dealing with simple machines, when dealing with complex systems of systems and miniaturized technologies, like unmanned aerial vehicles (UAVs), new technologies like augmented reality can rapidly and effectively support the maintenance operations.
White Paper

The Use of Imaging for Powder Metal Characterization and Contamination Identification

2018-04-05
WP-0008
As AM technologies are being used with higher frequencywithin the automotive and aerospace industries, the interest in powder characterization and contaminant identification is growing—especially for suppliers looking to gain entry into these highly regulated industries. Standards for powder materials and methods used for aerospace applications are still be developed, and regulatory agencies such as the Federal Aviation Administration have been requesting that standards be developed as guidance for the industry. Methods such as CCSEM and HLS could be viable options for suppliers needing to adhere to a powder specification by demonstrating compliance. Solutions exist to integrate such methods into a production environment as exemplified by RJ Lee Group.
Tech Insights

Balance of Plant: Integrating PEM Fuel Cells into Aircraft

2017-11-13
TI-0002
While all-electric aircraft remain at the bleeding edge of the aviation industry, incorporating technologies like proton exchange membrane fuel cells into existing aircraft can result in considerable auxiliary capability with low environmental impact. However, proper consideration must be given to supporting systems to achieve a reliable balance of plant-especially when those systems interface with existing aircraft architectures. The scope of the BoP is to manage and condition the reactant flows to and from the fuel-cell module and to provide power to system components.
Solution Notes

The Right Balance for Small UAVs: Defining top-level requirements for the power

2017-12-08
SN-0003
Small tactical UAVs (SUAVs) have made their mark in military operations with their ability to gather and provide localized, real-time information. Typical uses include perimeter surveillance of remote military compounds, over-the-horizon surveillance, and remote monitoring of critical logistics routes. However, their potential to take on increased and increasingly complex missions is hampered by their limited endurance. This work explores research done under the auspices of the European Commission’s Fuel Cell and Hydrogen Joint Undertaking on a fuel cell and battery hybrid energy storage system that could increase the total amount of onboard energy storage, while continuing to deliver the peak power needs of the SUAV.
Technical Paper

Gender and Age Influence on Fatality Risk from the Same Physical Impact Determined using Two-Car Crashes

2001-03-05
2001-01-1174
Studies using the double-pair-comparison method found that fatality risk from the same physical impact is (28 ± 3)% greater for females than for males, and increases with age after age 20 at compound annual rates of (2.52 ± 0.08)% for males and (2.16 ± 0.10)% for females. The purpose of the present study is to investigate fatality risk from the same physical impact versus gender and age using a different method and data distinct from those in the other studies. Female to male fatality risk was estimated using two-car crashes in which the gender of the two drivers differed. Fatality risk from the same impact is found to be (22 ± 9)% greater for females than for males, and to increase annually after age 20 by (2.86 ± 0.32)% for males and (2.66 ± 0.37)% for females. The relatively close quantitative agreement between the present and double-pair-comparison estimates increases confidence in the validity of double-pair-comparison methods and the present method.
Technical Paper

A New Tool for Corrosion Inhibitor Research

2001-03-05
2001-01-1176
Electrochemical techniques such as repassivation potential measurements and electrochemical impedance spectroscopy (EIS) have become important tools in corrosion and corrosion inhibitor research. However, these techniques reflect the response of the total surface area of the exposed sample and cannot distinguish between types of localized corrosion e.g. pitting or crevice corrosion. Current density mapping (CDM) is a technique that uses a fine stainless steel needle, vibrating at a set frequency and scans over the surface of a sample in a plane micrometers above the sample surface. By mapping the current distribution over a surface, sites of localized corrosion can be characterized and the effect of a corrosion inhibitor monitored.
Technical Paper

Biomechanics of the Patient Compartment of Ambulance Vehicles under Crash Conditions: Testing Countermeasures to Mitigate Injury

2001-03-05
2001-01-1173
There has been very limited research on the biomechanics of occupant safety in the ambulance environment. Occupant protection or crash testing safety standards for these unique vehicles are lacking in the United States. Recent studies have identified ambulances as high risk passenger transport vehicles. This study was conducted to identify some of the occupant safety hazards in the ambulance environment and to determine the efficacy of some countermeasures to mitigate ambulance occupant injury. Accelerator sled testing of the ambulance rear patient compartment (ambulance box or rear cabin) with Anthropomorphic Test Devices was conducted under frontal impact conditions with a target sled pulse was 26 G and 30 mph. The ambulance box was configured with instrumented and uninstrumented Anthropomorphic Test Devices positioned as in the real world environment.
Technical Paper

A Systems Modeling Methodology for Evaluation of Vehicle Aggressivity in the Automotive Accident Environment

2001-03-05
2001-01-1172
A systems modeling approach is presented for assessment of harm in the automotive accident environment. The methodology is presented in general form and then applied to evaluate vehicle aggressivity in frontal crashes. The methodology consists of parametric simulation of several controlled accident variables, with case results weighted by the relative frequency of each specific event. A hierarchy of models is proposed, consisting of a statistical model to define the accident environment and assign weighting factors for each crash situation case, and vehicle and occupant models for kinematic simulation of crash events. Head and chest injury results obtained from simulation are converted to harm vectors, in terms of probabilistic Abbreviated Injury Scale (AIS) distributions based on previously defined risk analyses. These harm vectors are weighted by each case’s probability as defined by the statistical model, and summed to obtain a total estimate of harm for the accident environment.
Technical Paper

Study of the Noise Characteristics of Motorcycle Silencers

2001-03-05
2001-01-1209
This paper describes methodologies developed to reduce the noise radiated from silencers while keeping or improving engine performance; i.e. whilst minimising the pressure loss through the silencer. This work was successfully developed to help motorcycle designers to meet the current legal noise limitations with minimum detriment to engine performance. Innovative designs for reactive silencers have resulted, with improved acoustic and engine performance levels, compared with traditional systems. The methodology was developed using the boundary element method (BEM). This method is able to calculate the acoustic variables in the interior and exterior fluid of the silencer. Furthermore, it is possible to simulate the temperature gradient along the silencer. A further important characteristic of the method is the ability to simulate the proper boundary conditions at the outlet without the need of hand calculations or “guesses”.
Technical Paper

Liquid Film Evaporation Off the Piston of a Direct Injection Gasoline Engine

2001-03-05
2001-01-1204
An optical access engine was used to image the liquid film evaporation off the piston of a simulated direct injected gasoline engine. A directional injector probe was used to inject liquid fuel (gasoline, i-octane and n-pentane) directly onto the piston of an engine primarily fueled on propane. The engine was run at idle conditions (750 RPM and closed throttle) and at the Ford World Wide Mapping Point (1500 RPM and 262 kPa BMEP). Mie scattering images show the liquid exiting the injector probe as a stream and directly impacting the piston top. Schlieren imaging was used to show the fuel vaporizing off the piston top late in the expansion stroke and during the exhaust stroke. Previous emissions tests showed that the presence of liquid fuel on in-cylinder surfaces increases engine-out hydrocarbon emissions.
Technical Paper

Influences of Gas Quality on a Natural Gas Engine

2001-03-05
2001-01-1194
1 The topic of investigation of this work was the influence of different gas qualities on the engine parameters and particularly on the air excess factor λ. For this research the normalized gases with extreme compositions were used. At stationary operation there are no differences of the leaning capability of the different gases. The gas with the highest content of inert components causes the lowest full load power, the highest fuel consumption and the highest cyclic irregularity. With the same air flow and the same injection duration for different gases result different air excess factors λ according to the density and to the necessary stoichiometric air quantity of each gas. This fact influences the λ at transient operation conditions as: cold starting, gas quality jump, or load increase, if there is no λ-control. With an active λ-control, which is today fast enough, especially with an adaptive system there are no problems with λ- differences.
Technical Paper

Transfer Path Analysis of Structure-Borne Shock Absorber Noise in a Passenger Car

2001-04-30
2001-01-1441
This paper describes a method to separate structure-borne noise, which comes from the shock absorber, from the measured vehicle interior sound pressure. The transfer path analysis (TPA) was used. Shock absorber was considered as an input source while the sound pressure at the driver seat as its output. It was found that the sound pressure at the driver seat position and accelerations at the shock absorber mounting points are strongly correlated. Using one-third octave band analysis, the contribution of shock absorber structure-borne noise to the driver seat sound pressure was analyzed. Also the relationship between the measured acceleration and sound pressure was studied.
Technical Paper

A Stiffness Optimization Procedure for Automobile Rubber Mounts

2001-04-30
2001-01-1445
Generally, it is well known that road noise generated by vibration from automobile tires and suspensions can be reduced by changing the stiffness of the rubber mounts installed in the suspension systems. Such stiffness, however, is rarely changed to avoid riding discomfort and so on. In this paper, a stiffness optimization method for suspension system rubber mounts that reduces road noise, and improves riding comfort as well, is presented. In the process, Road Noise Contribution Analysis (RNCA) is applied to the target vehicle to specify the major factors of road noise. Furthermore, the suspension system of the vehicle is investigated by Sensitivity Analysis using Measured FRF data (SAMF) to identify the optimal stiffness combination of rubber mounts. As a result, an effective stiffness combination of two mounts is specified to reduce road noise and to improve riding comfort.
Technical Paper

Sound Design in the Passenger Compartment with Active Noise Control in the Air Intake System

2001-04-30
2001-01-1432
In the future, the requirements of acoustic behavior in air intake systems will continue to increase. Active systems will be necessary to reach the higher legislative standards and customer expectations regarding noise levels. The optimization of the Active Noise Control System regarding the sound design in the interior is based on the transfer function between the engine and the passenger compartment as well as the design of the air intake system. This paper shows the development process, with a focus on the investigation of transfer functions in passenger cars and the computational calculation for the system configuration.
Technical Paper

Sounddesign - the BMW Inline Six-Cylinder Engine in Different Vehicle Applications

2001-04-30
2001-01-1428
The new inline six-cylinder engine from BMW notoriously sets new standards on objective performance in power and torque and fuel consumption as well as on “Laufkultur” (engine refinement). It has been a general movement in recent years to design engines that not only perform, but also improve driver's feedback for performance on an emotional level. New is the degree of differentiation of this new engine through distinctive sound design for the whole bandwidth of vehicle categories ranging from a 5-Series luxury sedan to a Z3 roadster, or an X5 sports utility vehicle to a 3-Series compact car. For each BMW class, the intake and exhaust systems of the inline 6-cylinder engines have been tuned to highlight the subjective impression of performance according to the appropriate vehicle type.
Technical Paper

Flow Visualization Study of an HVAC Module Operated in Water

2001-05-14
2001-01-1702
Centrifugal blowers serve as the primary source of airflow and aero-acoustic noise in automotive HVAC modules. Flow field measurements inside blowers indicate very complex flow patterns. A detailed flow visualization study was conducted on an actual HVAC fan module operated in water under dynamically similar conditions as those in air with the purpose of studying the complex flow patterns in order to improve the aerodynamic performance of the fan/scroll casing and diffuser components. Fan-scroll/diffuser interaction was also studied as function of fan speed. Conventional and special (shear thickening) dye injection flow visualization techniques were used to study the complex 3-dimensional vortical and unsteady flow patterns that occur in typical HVAC fans. A major advantage of the flow visualization technique using shear-thickening dye is its usefulness in high the Reynolds number flows that are typically encountered inside HVAC modules.
Technical Paper

Optimization of Vehicle Warm-up Using Simulation Tools

2001-05-14
2001-01-1705
A comprehensive simulation method is presented for the optimization of vehicle warm-up. Sophisticated one dimensional simulation methods based on network theory are used for flow simulation to limit computation time and guarantee high simulation quality. Partial integration of three dimensional flow simulation methods help to improve accuracy. Simulation sub-models for the engine, the HVAC system, and the passenger cabin are combined to simulate the warm-up process of the vehicle. This functionality is implemented in a modern software tool named KULI to support the development engineer as good as possible. Steady state and transient simulation are used to optimize the warm-up behavior.
Technical Paper

Comparison of CFD Simulation Methods and Thermal Imaging with Windscreen Defrost Pattern

2001-05-14
2001-01-1720
The measured windscreen defrost pattern for a saloon car has been compared with two CFD simulation methods and with the results obtained using a thermal imaging camera. The objectives were to determine: if CFD could be used with confidence to simulate defrost performance; the difference between the two CFD methods; the ability of the thermal imaging technique to predict defrost performance; the most appropriate use of these techniques during an HVAC development programme. There was a good comparison between the defrost pattern on the windscreen and the results from the thermal imaging camera and the two CFD methods. The CFD methods have been shown to be suitable for fault finding and recommending their use is reinforced for development work of ducts and vents in the HVAC system. Airflow direction and distribution could be implied from the thermal camera images, which makes it a suitable tool for fine tuning duct and vent designs at the final stages of the design programme.
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