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Viewing 31 to 60 of 61878
2011-04-12
Journal Article
2011-01-0166
David Sims-Williams, David Marwood, Adam Sprot
The rear end geometry of road vehicles has a significant impact on aerodynamic drag and hence on energy consumption. Notchback (sedan) geometries can produce a particularly complex flow structure which can include substantial flow asymmetry. However, the interrelation between rear end geometry, flow asymmetry and aerodynamic drag has lacked previous published systematic investigation. This work examines notchback flows using a family of 16 parametric idealized models. A range of techniques are employed including surface flow visualization, force measurement, multi-hole probe measurements in the wake, PIV over the backlight and trunk deck and CFD. It is shown that, for the range of notchback geometries investigated here, a simple offset applied to the effective backlight angle can collapse the drag coefficient onto the drag vs backlight angle curve of fastback geometries.
2011-04-12
Journal Article
2011-01-0509
Megumu Oshima, Kanya Nara
This paper describes the development of a design method and process for quality variation control. Conventional approaches utilizing Taguchi method [6,7,8] can quantify the sensitivities of parts characteristics on a system characteristic from both viewpoints of nominal value and variation. But the interpretation of the sensitivities depends on engineers' judgments. At the new process, function deployment has been introduced as the tool for breaking down hierarchically vehicle performance to the level of parts characteristics. And the relation between vehicle performance and parts characteristics is formulated based on a physical model in order to interpret the sensitivities more technically. The methodology combining the formulated function deployment and Taguchi method is referred to as design response analysis and variation effect analysis. These approaches can facilitate the interpretation of the quantified sensitivities considering the mechanism.
2011-04-12
Technical Paper
2011-01-0510
Megumu Oshima, Kanya Nara, Tatsuhiko Yoshimura
We have constructed a design review system in which Full Process and Quick Design Review processes are selectively used according to the degree of newness in a design change. The Full Process Design Review is conducted for a review of system or part designs having a high level of newness and the tools and process used in this review were standardized. The Quick Design Review is newly developed design review process that could be conducted in a quicker and simpler manner for designs involving a medium level of newness in order to effectively prevent design-related problems. The Quick Design Review uses a changes list and Design Review Based on Failure Mode (DRBFM) [1] worksheets to focus on the changed points. This method enables the engineers involved to identify problems and to devise solutions efficiently and effectively through discussions.
2011-04-12
Technical Paper
2011-01-0523
William Nicholas Dawes, William Kellar PhD, Simon Harvey PhD, Neil Eccles PhD
Successful product development, especially in motorsport, increasingly depends not just on the ability to simulate aero-thermal behavior of complex geometrical configurations, but also the ability to automate these simulations within a workflow and perform as many simulations as possible within constrained time frames. The core of these aero-thermal simulations - and usually the main bottleneck - is generating the computational mesh. This paper describes recent work aimed at developing a mesh generator which can reliably produce meshes for geometries of essentially arbitrary complexity in an automated manner and fast enough to keep up with the pace of an engineering development program. Our goal is to be able to script the mesh generation within an automated workflow - and forget it.
2011-04-12
Technical Paper
2011-01-0594
Silviu Pala, Thomas Schnell, Nicole Lynn Becklinger, Carolina Giannotti, Bo Sun, Hiroaki Tanaka, Ifushi Shimonomoto
DENSO International America, Inc. and the University of Iowa-Operator Performance Laboratory (OPL) have developed a series of new Multi-Modal Interface for Drivers (MMID) in order to improve driver safety, comfort, convenience and connectivity. Three MMID concepts were developed: GUI 1, GUI 2 and GUI 1-HUD. All three of the MMIDs used a new Reconfigurable Haptic Joystick (RHJ) on the steering wheel and new concept HMI Dual Touch Function Switches (DTFS) device. The DTFS use capacitive and mechanic sensing located on the back of the steering wheel as input operation devices. Inputs from the new controls were combined with a large TFT LCD display in the instrument cluster, a Head Up Display (HUD) and Sound as output devices. The new MMID system was installed in a Lexus LS-430. The climate control panel and radio panels of the LS-430 were used as a baseline condition to which the new designs were compared.
2013-04-08
Journal Article
2013-01-1230
Steffen Ostendorff, Joerg Sachsse, Heinz-Dietrich Wuttke, Jorge Meza Escobar
This paper presents an adaptive test approach to improve the structural testing of printed circuit boards (PCB) found in electronic automotive components. The approach makes use of FPGAs available on the PCBs, and its applicability is supported by the global trend taking place in the automotive industry of replacing ASICs with programmable devices such as FPGAs. For structural testing of PCBs, Boundary Scan (BScan) is mostly used. However, BScan has the disadvantage of being a static test method due to the slow execution speed reducing the fault coverage concerning dynamic faults. FPGAs support BScan as well, but they also offer a vast number of programmable resources. These resources can be configured for testing purposes. Our approach is to speed-up the testing process during the PCB manufacturing by moving data intensive processing from the external software side (Test-PC) to the programmable hardware side on-board (FPGA), reducing the data transfer over the slow JTAG interface.
2013-04-08
Technical Paper
2013-01-1233
Sreegururaj Jayachander
The current trend of going “green” in emerging automotive markets is, by the conversion of internal combustion engine based vehicle platforms into electrified vehicle platforms. While this method of electrification reduces the product development life cycle drastically due to the availability of a readymade platform, there are certain areas that are always overlooked. While focus is given on obvious and necessary elements like power train & battery packaging, weight reduction, high voltage safety, thermal management etc., electro-magnetic compatibility is neglected in the conversion process. This paper shall describe, in detail and in particular, the effect of electrical transients created by legacy elements, already existing in the baseline platform. This is an outcome of electro-magnetic compatibility challenges faced during the conversion of an internal combustion engine powered vehicle into an electric vehicle.
2013-04-08
Journal Article
2013-01-1228
Graciela Becci, Gunwant Dhadyalla, Alexandros Mouzakitis, James Marco, Andrew David Moore
Testing real-time vehicular systems challenges the tester to design test cases for concurrent and sequential input events, emulating unexpected user and usage profiles. The vehicle response should be robust to unexpected user actions. Sequence Covering Arrays (SCA) offer an approach which can emulate such unexpected user actions by generating an optimized set of test vectors which cover all possible t-way sequences of events. The objective of this research was to find an efficient nonfunctional sequence testing (NFST) strategy for testing the robustness of real-time automotive embedded systems measured by their ability to recover (prove-out test) after applying sequences of user and usage patterns generated by combinatorial test algorithms, considered as “noisy” inputs. The method was validated with a case study of an automotive embedded system tested at Hardware-In-the-Loop (HIL) level. The random sequences were able to alter the system functionality observed at the prove-out test.
2013-04-08
Technical Paper
2013-01-1229
Ajinkya Chinchwadkar, Alok Khare
Currently, OEMs worldwide are emphasizing more upon development and implementation of new electrical features on existing vehicles [3]. However, development and implementation of new electrical features on existing vehicle platforms create architectural as well as packaging challenges. These challenges are augmented due to following: the need to implement such features across different body styles of vehicles that are based on same or different architectures different requirement for a feature based upon market requirement This paper analyzes these challenges to help in providing design solutions for successful implementation of new features as per following requirements: 1 Provide optimum design to have low cost and high quality for existing vehicle platforms2 Provide spare capacity while designing new vehicles or architectures
2014-01-15
Journal Article
2013-01-9091
Dongfang Jiang
To get a sequence retainable rainflow cycle counting algorithm for fatigue analysis, an alternate equivalent explanation to rainflow cycle counting is introduced, based on which an iterative rainflow counting algorithm is proposed. The algorithm decomposes any given load-time history with more than one crest into three sub-histories by two troughs; each sub-history with more than one crest is iteratively decomposed into three shorter sub-histories, till each sub-history obtained contains only one single or no crest. Every sub-history that contains a single crest corresponds to a local closed (full) cycle. The mean load and alternate load component of the local cycle are calculated in parallel with the iterative procedure.
2014-01-15
Journal Article
2013-01-9095
Lindita Prendi, Allan King, Edwin Tam
Environmental concerns and rising fuel costs are driving Ontario's municipalities and fleet operators to consider alternative vehicle technologies. Elevated fuel consumption and air emissions are attributed to the unique operations of fleet vehicles and in particular, during idling. While drivers of passenger vehicles may have the option of simply not idling, fleet and emergency vehicle operators, may need to keep the vehicle operating to supply power to critical onboard equipment. These demands may be exacerbated during seasonal, temperature extremes. However, prolonged idling can impose significant environmental and economic burdens. Hybrid vehicles have yet to be utilized widely by Ontario's fleets, but there are other approaches to reduce emissions, including alternative “green” technologies to operate in-vehicle equipment and maintain fleet vehicle capabilities instead of idling.
2004-07-19
Technical Paper
2004-01-2494
N. M. Samsonov, E. A. Kurmazenko, L. I. Gavrilov, N. S. Farafonov, N. V. Pavlova, T. N. Pavlova, V. Ju. Proshkin, S. Ju. Romanov, A. M. Rjabkin, A. S. Guzenberg, A. N. Slyshchenkov, O. V. Kirjushin
The Regenerative Atmosphere Revitalization and Monitoring system (ARMS), been part of Integrated Life Support System (ILSS), is intended for maintenance in the manned modules of a necessary chemical composition of an artificial gas atmosphere (AGA) on base of the crew metabolism product transform to environment initial components. Generally, the ARMS structure includes the individual systems and units intended for: → oxygen generation; → carbon dioxide removal and it concentration; → trace contaminants removal; → carbon dioxide reduction with the goal to produce an additional quantity of water necessary to increase the degree of the oxygen loop clousure. The ARMS structure of the International Space Station (ISS) Russian Segment (RS) includes the Electron-VM Oxygen Generation System (OGS), Vozdukh Carbon Dioxide Removal System (CDRS) and SBMP Trace Contaminants Removal Means (TCRM) installed in the Service Module.
2004-07-19
Technical Paper
2004-01-2488
Cynthia Pederson, Richard M. Lueptow
A promising technology for recycling wastewater on long term space missions is rotating reverse osmosis (RO). Rotating RO utilizes Taylor vortices, a flow structure in the annulus of the device, that provide increased transport of the water through the RO membrane compared to conventional RO systems. A high pressure rotating RO filter and fluid circuit have been designed and fabricated for use in long term tests. Preliminary results indicate that an increase in the operating pressure by a factor of three can improve the flux by a factor of four while maintaining high rejection of the contaminants.
2004-07-19
Technical Paper
2004-01-2489
N. M. Samsonov, L. S. Bobe, N. S. Farafonov, V. A. Soloukhin, S. Ju. Romanov, P. O. Andrejchuk, N. N., Protasov, Ju. E. Sinjak, V. M. Skuratov
The paper deals with the performance data of the service module Zvezda integrated water supply system of the International Space Station (ISS) as of March 31, 2004. The water supply and demand balance are analyzed. It is shown that water recovery from humidity condensate has been especially important when water delivery by Space Shuttles was terminated. The SRV-K contribution in potable water supply for crew needs was up to 76%. The data of humidity condensate and recovered water compositions are reviewed. The effective cooperation of the international partners on part of life support is shown. Water recovery future prospects are discussed.
2004-07-19
Technical Paper
2004-01-2486
Philippe A. Souvestre
Human performance deterioration in extreme conditions challenges the viability of critical scenarios during a space mission. Exposure to space flight environment, including microgravity appears to increase the stress on the sensory-motor controls regulatory system in the brain because it is calibrated to operate under gravity. Any pre-existing central dysfunction can allow an input overload which can cascade to and alter other related functions down the functional hierarchy, such as physical (fine postural control, coordination and dexterity, strength, reaction time, fatigue, space perception/orientation) cognitive(trajectory control, attention and vigilance, time awareness, decision making, concentration, and memory), and emotional (motivation, self-control, calmness/aggressiveness). This phenomenon has direct influence on an individual’s tendency for “error proneness”.
2004-07-19
Technical Paper
2004-01-2483
Vishal Nangalia, James Habershon
Humans are able to acclimatize and later adapt to extreme altitudes, and this will be shown to be beneficial to the human with respect to microgravity and spacecraft environment. Treating the astronaut as a subsystem, which can be enhanced and modified to ultimately benefit the whole spacecraft is an approach that is necessary to forge the next generation of human spaceflight. A spacecraft environment that is maintained at a pressure of 16 kPa (primarily oxygen) would be both well within the realm of possibility of an astronaut’s physiology and would provide significant benefits for the all the subsystems of a spacecraft from the large intra-stellar spaceship to the EVA suit.
2004-07-19
Technical Paper
2004-01-2484
Philippe A. Souvestre
Posture and gait controls underlie the fundamental physical and cognitive human factors necessary for astronauts’ safety and performance in Space. This central subsystem is adversely affected when exposed to an extreme or hostile environment. A specific stimulation, using dermal optical sensitivity, can be provided to the central nervous system to counteract peripheral stimulations due to microgravity as well as other negative stressors. We believe using dermal optical sensitivity-based stimulation can be key in the performance enhancement necessary to ensure human based space mission viability and success.
2004-07-19
Technical Paper
2004-01-2479
Larry Toups
The prudent use of analog facilities for future missions to other planetary bodies has been validated in many locations. Site specific analog projects such as the Haughton-Mars Project and Devon Island have proven beneficial by conducting terrestrial science type missions and learning from them. An integrated facility oriented to ground testing allows the opportunity to bring many other activities associated with a future exploration mission together and add value to the analog experience. The focus of such a facility as the Advanced Integration Matrix (AIM) at Johnson Space Center includes operations and various technical disciplines needed to conduct the mission. These facilities bring together emerging and developing technologies and identify the issues and risks when they are interfaced with each other. The purpose of this paper is to identify areas of near term benefit of ground test facilities focused on future missions in space.
2004-07-19
Technical Paper
2004-01-2478
Richard Boulanger, David Overland
Technologies that facilitate the design and control of complex, hybrid, and resource-constrained systems are examined. This paper focuses on design methodologies, and system architectures, not on specific control methods that may be applied to life support subsystems. It has been estimated that 60–80% of the effort in developing complex control systems is software development, and only 20–40% is control system development [1]. It has also been shown that large software projects have failure rates of as high as 50–65% [2,3]. Concepts discussed include the Unified Modeling Language (UML) and design patterns with the goal of creating a self-improving, self-documenting system design process. Successful architectures for control must not only facilitate hardware to software integration, but must also reconcile continuously changing software with much less frequently changing hardware [4]. These architectures rely on software modules or components to facilitate change.
2004-07-19
Technical Paper
2004-01-2476
Harry W. Jones, Robin L. Dillon-Merrill, Gretchen A. Thomas
The Advanced Integration Matrix (AIM) Project will investigate systems integration and test for the Vision for Space Exploration. The goal of AIM is to reduce the risk of future human missions by identifying those significant risks that Earth-based integration and test can reduce. AIM will focus on the mission requirements that need verification beyond component/subsystem testing, but that can still be tested on Earth. In order to help set priorities for AIM, this paper describes a preliminary Probabilistic Risk Analysis (PRA) framework that was developed based on the Vision for Space Exploration. The PRA provides a decision-making tool to balance mission risk, performance, and cost.
2004-07-19
Technical Paper
2004-01-2474
Robert T. Bigelow, Richard R. Chu, Jay K. Ingham
This Life Support Laboratory consists of a simulator of the spacecraft called Nautilus, which houses Air Revitalization Subsystem, Atmospheric Control and Supply, and Fire Detection and Suppression in the Equipment Area. There are supporting facilities including a Human Metabolic Simulator, simulated Low and Moderate Temperature Coolant Loop, chemical analysis bench, purified water supply, vacuum and gas supplies. These facilities are scheduled to be completed and start to operate for demonstration purposes by March 2005. There are an ARES Ground Model (AGM) and a Trace Contaminant Control Assembly in the ARS. The latter will be integrated with the AGM and a Condensing Heat Exchanger. The unit of AGM is being engineered, built, and will be delivered in early 2005 by EADS Space Division. These assemblies will be operated for sensitivity analysis, integration and optimization studies. The main goal is the achievement for optimal recovery of oxygen.
2004-07-19
Technical Paper
2004-01-2469
MariaCristina Tosi, Luca Tentoni, Antoine Joulot, Jose' Antonio, Romera Perez
The Automated Transfer Vehicle (ATV) Thermal Control System (TCS) has the task to ensure the required internal environment at level of pressurized module and to thermally control the not pressurised modules and installed equipment, using passive and active control means, in response to the relevant applicable requirements. The ATV vehicle is assially subdivided into three main modules: the Integrated Cargo Carrier (ICC), the Equipped Avionics Bay (EAB) and the Equipped Propulsion Bay (EPB). Each of these modules present elaborated and specific thermal design solutions, to satisfy the different required operative tasks. The extensive thermal analysis campaign performed at ATV vehicle level and in progress for the next Qualification Review (QR) to justify and support the thermal control design solutions and verification status is described.
2004-07-19
Technical Paper
2004-01-2468
W. Andrew Jackson, Audra Morse, Tania Ho, Greg Collins
Biological pre-treatment of liquid waste could potentially offer equivalent mass savings for long term space habitation. Previous work has demonstrated the technological feasibility. However, limited work has been conducted on optimizing the biological reactors or fully characterizing the biochemical transformations occurring within the reactors. The objective of these studies was to provide long-term operating data on a proposed and well studied reactor configuration, and explore the effects of RR on system performance. The water recovery system has been in successful operation for over 2 years. Data to be presented will include both typical removal efficiencies for nitrogen species, DOC as well as important water quality parameters. In addition the effect of recycle ratio (2X, 5X, 10X, and 20X) will be quantified.
2004-07-19
Technical Paper
2004-01-2466
Arthur A. Teixeira, David P. Chynoweth, John M. Owens, Elana Rich, Amy L. Dedrick, Patrick J. Haley
This paper reports on fabrication, installation, start-up and shakedown of a full-scale prototype solid waste management system designed to be a principal component in a bio-regenerative solid waste management system to support a 6-person crew on long-term space missions. System design is based upon a patented process for odorless bioconversion of organic solid wastes to biogas and compost by anaerobic digestion. The system consists of five reactors and two gas-liquid separators designed for operation under conditions of micro-gravity. During any week of operation, one reactor is used for feed collection and compaction, three for stage-wise anaerobic composting, and one for post-treatment aerobic stabilization, while simultaneously serving as a bio-filter in the pretreatment of cabin air within the air revitalization subsystem. Each reactor carries its one-week charge of feedstock through all five stages of bioconversion in completing a five-week sequential batch cycle.
2004-07-19
Technical Paper
2004-01-2467
Dawn R. Whitaker, John W. Lane, James E. Alleman, Rebecca Riaño
Solids thermophilic aerobic reactor (STAR) processing of biodegradable solid waste residuals uses high temperature conditions to reduce waste volume, inactivate pathogens, and render products that may enter the recycle system by providing plant substrate, fish food, and mushroom growth medium. The STAR process recovers and enables the reuse of nutrients, water, and carbon. During the time of this study, STAR was operated at a 3% solids loading rate, with an 11-day retention time at a temperature range of 50-55°C. This document presents the following details: a the evolution to date of the STAR reactor b review of reactor operation and analytical methods c a synopsis of the performance results and related discussion, and d a synopsis of future goals relative to this project's associated research roadmap.
2004-07-19
Technical Paper
2004-01-2465
Richard F. Strayer, Kristina Reid, Tony J. Rector, Mary P. Hummerick, Jay L. Garland
The purpose of this research is to determine the feasibility of a unique denitrifying composter to stabilize trash from space-habitation (STS, ISS, ALS) life support activities. Design criteria were derived from variables to be manipulated and those to be held constant. A pre-existing aerobic composter was used and engineering tests run to ensure that requirements were met. Key experimental variables were identified: NO3- concentration and rate of addition, O2 concentration, mixing duration and frequency, and inoculum. Independent variables were pH, temperature, moisture, C:N ratio, feed material, size reduction, feed addition rate, and mode of operation. Important performance parameters included: maximization of desired outcomes – BOD5 removal, CO2 production, waste stabilization, and denitrification – and minimization of undesired products – N2O, NH3, and volatile organic compounds.
2004-07-19
Technical Paper
2004-01-2464
Kimberly L. Jones, Joffrey Leevy, Samantha LaHee
This study evaluates the use of microfiltration (MF), low pressure RO (LPRO) and nanofiltration (NF) membranes for use in a treatment train for recycled wastewater. Specifically, a MF membrane will act as pretreatment for RO/NF membranes. Contaminants of concern for the membrane system include biosolids and surfactant micelles for the MF membrane, and ammonium ions, urea, surfactant monomers, and salts for the RO/NF system. These contaminants will be reduced to meet existing EPA and NASA standards using these membrane systems. The goal is to achieve high removal rates (>95% for these contaminants) while maintaining high flux and low fouling of the membranes, as membrane treatment is the last treatment step before final disinfection of the recycled wastewater. This paper outlines the experimental plan for designing the integrated membrane system and explains the potential benefits of such a system.
2004-07-19
Technical Paper
2004-01-2462
Audra Morse, W. Andrew Jackson, Srikara Kaparthi
Simulated wastewater, known as early surface mission wastewater, treated in previous experiments at JSC and TTU included urinal flush water, shower water, humidity condensate, oral hygiene water, and hand wash water. In reality, there is a difference between the early surface mission wastewater and the International Space Station wastewater. The ISS does not have a shower or hand wash, which contributes approximately 59 percent of the make-up water treated. The average influent ammonia concentration in the simulated wastewater treated by the TTU water reclamation system frequently exceeds 500 mg/L. Removal of the shower make-up water in simulated wastewater will result in a significant increase in the ammonia concentration, resulting in higher influent pH values and ammonia concentrations that may be inhibitory. Biological treatment technologies have suitably treated the diluted waste stream but a more concentrated waste stream may present a greater challenge.
2004-07-19
Technical Paper
2004-01-2461
Eric McLamore, Audra Morse, Andrew Jackson, Ken Rainwater
The objective of this study was to investigate the potential of membrane-aerated bioreactors as long term microgravity compatible nitrifying biological water processors (BWP). A small-scale (1/20th) replica of the water recovery system (WRS) at JSC has been operated and extensively analyzed at Texas Tech University (TTU) for the last 3 years. The current nitrifying tubular reactor at JSC and TTU has experienced difficulty in maintaining efficiency and low maintenance. In an attempt to increase the efficiency of the biological portion of the WRS, a membrane-aerated bioreactor (MABR) was constructed and operated using the same parameters as the TTU-WRS in August 2003. The MABR is downstream of an anaerobic packed bed and is designed to promote nitrification (NH4 → NOx). The MABR achieved a percent nitrification of 61% and 55% for recycle ratios of 10 and 20, respectively.
2004-07-19
Technical Paper
2004-01-2457
Jeffery T. Iverson, Thomas M. Crabb, Mark C. Lee, Bill Butrymowicz
Unique challenges arise during the design of temperature and humidity control systems (THCS) for use in microgravity. The design of the Plant Research Unit’s (PRU) THCS builds on the experience gained during the Biomass Production System (BPS) project and extends the understanding of the critical design variables and necessary technical advancements to allow for longer on-orbit operation. Previous systems have been limited by loss of prime, clogging in the porous plates and component reliability. Design of THCSs for long-duration space flight experiments requires the mitigation of these issues as well as a complete understanding of the relevant design variables. In addition to the normal design variables (e.g. mass, power, volume), a complex and interdependent relationship exists between the THCS variables including operational temperature range, operational humidity range, required humidity condensation rate and system air flow.
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