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White Paper

Innovative Assembly Systems for the Aerospace Industry

2017-10-31
WP-0004
The aerospace industry is facing new challenges to meet burgeoning customer demand. An unprecedented number of orders for commercial aircraft is forcing aerospace manufacturing to make gains in efficiency throughout aircraft production and operation. However, current manufacturing systems are using technologies and production methods unsuited to a future dynamic market. To ensure its profitability, the aerospace industry must seize the opportunity to innovate and readdress approaches to manufacturing. This whitepaper looks at four advanced manufacturing (AM) solutions designed to improve assembly process efficiency, automation, and accuracy.
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

Dynamic Moving Mesh CFD Study of Semi-truck Passing a Stationary Vehicle with Hood Open

2007-04-16
2007-01-0111
This paper examines the aerodynamic forces on the open hood of a stationary vehicle when another large vehicle, such as an 18-wheel semi-truck, passes by at high speed. The problem of semi-truck passing a parked car with hood open is solved as a transient two-vehicle aerodynamics problem with a Dynamic Moving Mesh (DMM) capability in commercial CFD software package FLUENT. To assess the computational feasibility, a simplified compact car / semi-truck geometry and CFD meshes are used in the first trial example. At 70 mph semi-truck speed, the CFD results indicate a peak aerodynamic force level of 20N to 30N on the hood of the car, and the direction of the net forces and moments on the hood change multiple times during the passing event.
Technical Paper

Development of Advanced Safety Motorcycle

2006-11-13
2006-32-0112
In an effort to improve the technology of motorcycle safety, we have developed an advanced motorcycle using electronic control and information communication technologies. The Motorcycle AFS (Adaptive Front-lighting System) measures the bank angle and rotates the headlight to the rolling direction. As a result, the AFS improves the visibility of a motorcycle that is cornering at nighttime. The Motorcycle Night Vision System early detects pedestrians ahead at nighttime by using an infrared camera. This system captures infrared camera images that are not visible to the naked eye, extracts the figure of pedestrians by image processing, and provides the rider with the information on the presence of detected pedestrians.
Technical Paper

LDA Measurement of an Intermittent High-Speed Flow inside a Micro Wave Rotor Cell

2007-01-23
2007-01-0010
Velocity measurement of an intermittent high-speed flow inside a micro wave rotor cell was carried out using a laser Doppler anemometry (LDA). The cell is 3 × 3 mm rectangular tube, whose length is 42 mm. The pressure ratio and rotor speed of the wave rotor were set at 2.5 and 5,000 rpm, respectively. Ethanol droplets were seeded into the flow as scattering particles. By use of laser beam expanders, the probe volume of the LDA optics was minimized, and sub-millimeter special resolution is realized while a wide velocity range (-100 to 300 m/s) is kept. It is shown that the velocity histories at local positions inside the wave rotor cell can be obtained with the LDA optics. The rapid velocity increase and decrease, due to the primary and secondary shock waves, are observed, and the propagation speed of the shock waves was estimated. It is shown that the velocity profile inside the cell is flat and that the boundary layer thickness inside the cell is smaller than 0.5 mm.
Technical Paper

Transit Bus Design Effects Utilizing Improved Steel or Fiber Reinforced Composite Structures

2007-04-16
2007-01-0457
A typical production transit bus with vertical pillars of small section size, low gauge and low strength steel, exhibits extensive lateral pillar side-sway collapse (matchboxing) in rollover impacts. This matchboxing allows rollover of the bus onto its roof. LS-DYNA simulations demonstrate that roof pillars of high strength steel or inexpensive E-glass fiber reinforced polymer (FRP) pultrusions can prevent matchboxing and arrest the rollover of the bus. However, for the same space envelope, pultruded FRP pillars can be at least 41% lighter than high strength steel square tubes exhibiting the same bending moment capacity.
Technical Paper

Structural Strengthening of Vehicle Chassis with Adhesives

2007-04-16
2007-01-0458
The modern automotive industry develops innovative vehicle designs to meet increasing economic and performance demands of their customers. Material mixes of high-strength steel, aluminum, magnesium, composites and others are used to meet these demands. For combinations such as these, adhesive bonding is needed for additional structural benefit in addition to the conventional joining methods. To successfully use adhesives the ability to predict the performance and physical properties for the life of the vehicle are needed. The implementation of these adhesives into computer simulation is presented, and the results of various durability tests are discussed in this paper.
Technical Paper

Design of Dual Sliding Door Mechanism for a Small Sized Car

2007-04-16
2007-01-0461
Swing-out doors can easily cause damage to adjacent parked vehicles in tight parking spaces. Also, they are not traffic-friendly when the vehicles are parallel parked on busy road sides. This paper makes an attempt to come up with an innovative to design and develop a mechanism for dual sliding doors for a small sized car. The doors are supported only on two points of contact as compared to the usual sliding minivan doors which have three contact supports for sliding. These two points are called the “Upper control link and Lower support arm”. To open the door, first the door, has to push out by 90 degrees and then it has to slide in the fore-aft direction to open or close. For the doors, a track was placed just below the window at the beltline location and a triangular sub-roller assembly was designed for sliding motion.
Technical Paper

A Value Analysis Tool for Automotive Interior Door Trim Panel Materials and Process Selection

2007-04-16
2007-01-0453
This paper describes a computerized value analysis tool (VAT) developed to aid automotive interior designers, engineers and planners to achieve the high levels of perceived quality of materials used in automotive door trim panels. The model requires a number of inputs related to types of materials, their manufacturing processes and customer perceived quality ratings, costs and importance of materials, features located in different areas of the door trim panel, etc. It allows the user to conduct iterative evaluation of total cost, total weighted customer perceived quality ratings, and estimates of perceived value (perceived quality divided by cost) for different door trim areas as well as the entire door trim panel. The VAT, thus, allows value and cost management related to materials and processing choices for automotive interiors.
Technical Paper

Dynamic Analysis of Vehicle Trunk Lid with 4-Bar Link Structure

2007-04-16
2007-01-0455
The electronic-control technique using the hydraulic systems has been developed in the automobile industry. Also, the importance of the gas lifter has been increased because of its various applications and the convenience in minimization of a layout about the vehicle hood and the trunk lid. The reaction force, the gas injection-pressure, the effort and the temperature variation characteristics are determined by a trial and error method, when the shape of the trunk lid hinge changes to the link shape. As a result, it shows a tendency to the waste of time and cost. In case of the vehicle's trunk lid system with a hinge having 4-bar link structure, the installation load analysis of the gas lifter has been carried out using ADAMS program for computing the effort and the dead point of the trunk lid. In the present study, the efficiency estimation and analytical methods are presented in the opening and shutting devices of the trunk lid having the 4-bar link structure.
Technical Paper

Particulate and Hydrocarbon Emissions from a Spray Guided Direct Injection Spark Ignition Engine with Oxygenate Fuel Blends

2007-04-16
2007-01-0472
The blending of oxygenated compounds with gasoline is projected to increase because oxygenate fuels can be produced renewably, and because their high octane rating allows them to be used in substitution of the aromatic fraction in gasoline. Blending oxygenates with gasoline changes the fuels' properties and can have a profound affect on the distillation curve, both of which are known to affect engine-out emissions. In this work, the effect of blending methanol and ethanol with gasoline on unburned hydrocarbon and particulate emissions is experimentally determined in a spray guided direct injection engine. Particulate number concentration and size distribution were measured using a Cambustion DMS500. These data are presented for different air fuel ratios, loads, ignition timings and injection timings. In addition, the ASTM D86 distillation curve was modeled using the binary activity coefficients method for the fuel blends used in the experiments.
Technical Paper

Application of Tailor Rolled Blank in Vehicle Front End for Frontal Impact

2007-04-16
2007-01-0675
Lighter weight and lower cost have been pursued in automotive industry. Traditionally, metal sheets of uniform thickness are used for stamping or forming vehicle structural parts. For a desired structure, a metal sheet with varying thickness is desirable. It not only saves material but also increases design flexibility. For example, some areas of a cross member require thicker thicknesses to support localized, larger loading, while for other areas, where there is no localized loading, thinner thicknesses can be used to save material. Tailor Rolled Blank (TRB) is an emerging manufacturing technology which allows engineers to change blank thickness continuously within a sheet metal, virtually eliminating the need for welding local reinforcements in the part. TRB also provides simpler structural design due to smooth, rolled transitions, which prevent stress concentrations in the finished part.
Technical Paper

Quantitative Mixing Measurements in a Vaporizing Diesel Spray by Rayleigh Imaging

2007-04-16
2007-01-0647
This paper details the development and application of a Rayleigh imaging technique for quantitative mixing measurements in a vaporizing diesel spray under engine conditions. Experiments were performed in an optically accessible constant-volume combustion vessel that simulated the ambient conditions in a diesel engine. Two-dimensional imaging of Rayleigh scattering from a diesel spray of n-heptane and well-characterized ambient was accomplished by using a 532 nm Nd:YAG laser sheet and a low-noise back-illuminated CCD camera. Methods to minimize interference from unwanted elastic scattering sources (e.g. windows, particles) were investigated and are discussed in detail. The simultaneous measurement of Rayleigh scattering signal from the ambient and from the diesel spray provides important benefits towards making the technique quantitative and accurate.
Technical Paper

Transient Dynamic Analysis of Suspension System for Component Fatigue Life Estimation

2007-04-16
2007-01-0638
For suspension systems, fatigue and strength simulations are accomplished mostly at the component level. However, the selection of loading conditions and replication of boundary conditions at the component level may be difficult. A system level simulation eliminates most of the discrepancy between component level and vehicle level environment yielding realistic results. Further advantage of system level simulation is that the boundary conditions are limited to suspension mounting points at body or frame and the loading is limited to wheel-end or tire patch loading. This provides for a robust set of boundary constraints that are known and repeatable, and loads that are simpler and of relatively higher accuracy. Here, the nonlinear transient dynamic behavior of a suspension system along with its frame and mounting was simulated using a multibody finite element analysis (FEA).
Technical Paper

Development of Low Friction Washer for AT·CVT (Torque Converter)

2007-04-16
2007-01-0573
Various needle bearings and metal thrust washers are used in automatic transmissions (ATs and CVTs) for automobiles, however, in recent years thrust washers made of engineering plastics are begining to be adopted, because of their superiority in saving space, reducing weight and cost. This paper reports the newly developed low friction thrust washer made of engineering plastic for torque converters of AT·CVT.
Technical Paper

Foaming Visualization of Thermoplastic Polyolefin (TPO) Blends with N2

2007-04-16
2007-01-0572
Polymers are often blended to create compounds with new or enhanced properties in order to compensate for an individual polymer's weakness or lack of inherent properties. In the field of polymer foaming, polymer blends are also used to generate fine-cell structures via heterogeneous nucleation. Recently, an interest in physical blowing agents, such CO2 and N2, has increased because of their low impact on the environment. It has thus become additionally important to pursue research on the foaming of polymer blends employing these particular physical blowing agents in an effort to keep up with the demand for environmentally friendly products. In this study, thermoplastic polyolefin (TPO) blends were prepared with polypropylene (PP) and a metallocene-based polyolefin elastomer (POE) using twin-screw extruders and a batch mixer.
Technical Paper

Simulation Process to Investigate Suspension Sensitivity to Brake Judder

2007-04-16
2007-01-0590
Brake judder, which is a low frequency excitation of the suspension and thus, the body structure during low-G braking, is mainly felt at the steering wheel and throughout the vehicle structure. Brake judder is a problem that costs manufacturers millions of dollars in warranty cost and undesirable trade offs. The magnitude of judder response depends not only on the brake torque variation, but also on the suspension design character-istics. This paper discusses the judder simulation process using ADAMS software to investigate the suspension design sensitivity to the first order brake judder performance. The paper recommends “tuning knobs” to suspension designers and vehicle development engineers to resolve issues in the design and development stages. Various suspension design varia-bles including geometry and compliances as well as brake related characteristics were investigated.
Technical Paper

Combining DFSS and Multi-body Dynamics for Vehicle Ride Tuning

2007-04-16
2007-01-0586
A methodology involving Design for Six Sigma (DFSS) and Multi-body dynamic simulation is employed to tune a body-on-frame vehicle, for improved ride (shake) performance. The design space is limited to four sets of symmetric body mounts for a vehicle. The stiffness and damping characteristics of the mounts are the control factors in the virtual experiment. Variation of these design parameters from the nominal settings, as well as axle size, tire and wheel combinations, tire pressure, shock damping, and vehicle speed constitute the noise factors. This approach proves to be an excellent predictor of the vehicle behavior, by which much insight as to influence of each parameter on vehicle performance is gained. Ultimately, specific recommendations for the control factor settings are provided. Subsequent hardware builds show excellent agreement with the analytical model and suggested tuning.
Technical Paper

Viscous Fan Drive Model for Robust Cooling Air Flow Simulation

2007-04-16
2007-01-0595
One Dimensional models for front end air flows through the cooling system package are very useful for evaluating the effects of component and front end geometry changes. To solve such models for the air flow requires a robust iterative process that involves a number of non-linear sub-models. The cooling fan (s) constitute a major part of the difficulty, especially when they employ a viscous or “thermal” fan drive. This drive varies the torque coupling between the input and output shafts based on the radiator outlet air temperature. The coupling is achieved by viscous shear between two grooved disks and is regulated by a bimetal strip valve that varies the amount of fluid between the disks. This paper presents a mathematical model by which the input/output speed ratio may be determined as a function of the air temperature and input speed. Coefficients in the model are estimated from standard supplier performance information.
Technical Paper

Morphing and Parametrization Technologies for CFD Applications

2007-04-16
2007-01-0597
Computational Fluid Dynamics (CFD) Analysis has been playing a significant role in designing better products in a shorter time duration. However, if we use traditional CFD methodologies, the analysis engineer always lags behind the product design because the CAD geometry needs to be created prior to the CFD model creation. This paper demonstrates how CFD model Morphing, Concept modeling and Parametrization Technologies can be used so that the CFD engineer can effectively lead the design process. Morphing, Concept modeling and Parametrization technologies can be very effectively used during the following stages of product development.
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