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Viewing 1 to 30 of 4568
2010-10-25
Journal Article
2010-01-2254
Russell P. Fitzgerald, Richard R. Steeper
An infrared laser absorption technique has been developed to measure in-cylinder concentrations of CO in an optical, automotive HCCI engine. The diagnostic employs a distributed-feedback, tunable diode laser selected to emit light at the R15 line of the first overtone of CO near 2.3 μm. The collimated laser beam makes multiple passes through the cylinder to increase its path length and its sampling volume. High-frequency modulation of the laser output (wavelength modulation spectroscopy) further enhances the signal-to-noise ratio and detection limits of CO. The diagnostic has been tested in the motored and fired engine, exhibiting better than 200-ppm sensitivity for 50-cycle ensemble-average values of CO concentration with 1-ms time resolution. Fired results demonstrate the ability of the diagnostic to quantify CO production during negative valve overlap (NVO) for a range of fueling conditions.
2011-04-12
Journal Article
2011-01-0728
Amandeep Singh, Zissimos Mourelatos, Efstratios Nikolaidis
Reliability is an important engineering requirement for consistently delivering acceptable product performance through time. As time progresses, the product may fail due to time-dependent operating conditions and material properties, component degradation, etc. The reliability degradation with time may increase the lifecycle cost due to potential warranty costs, repairs and loss of market share. Reliability is the probability that the system will perform its intended function successfully for a specified time interval. In this work, we consider the first-passage reliability which accounts for the first time failure of non-repairable systems. Methods are available in the literature, which provide an upper bound to the true reliability which may overestimate the true value considerably. Monte-Carlo simulations are accurate but computationally expensive.
2011-04-12
Journal Article
2011-01-0725
Zissimos Mourelatos, Jing Li, Vijitashwa Pandey, Amandeep Singh, Matthew Castanier, David A. Lamb
Understanding reliability is critical in design, maintenance and durability analysis of engineering systems. A reliability simulation methodology is presented in this paper for vehicle fleets using limited data. The method can be used to estimate the reliability of non-repairable as well as repairable systems. It can optimally allocate, based on a target system reliability, individual component reliabilities using a multi-objective optimization algorithm. The algorithm establishes a Pareto front that can be used for optimal tradeoff between reliability and the associated cost. The method uses Monte Carlo simulation to estimate the system failure rate and reliability as a function of time. The probability density functions (PDF) of the time between failures for all components of the system are estimated using either limited data or a user-supplied MTBF (mean time between failures) and its coefficient of variation.
2011-04-12
Journal Article
2011-01-0726
Dan Ghiocel, Dan Negrut, David A. Lamb, David Gorsich
This research paper addresses the ground vehicle reliability prediction process based on a new integrated reliability prediction framework. The integrated stochastic framework combines the computational physics-based predictions with experimental testing information for assessing vehicle reliability. The integrated reliability prediction approach incorporates the following computational steps: i) simulation of stochastic operational environment, ii) vehicle multi-body dynamics analysis, iii) stress prediction in subsystems and components, iv) stochastic progressive damage analysis, and v) component life prediction, including the effects of maintenance and, finally, iv) reliability prediction at component and system level. To solve efficiently and accurately the challenges coming from large-size computational mechanics models and high-dimensional stochastic spaces, a HPC simulation-based approach to the reliability problem was implemented.
2000-06-12
Technical Paper
2000-05-0220
Josef Berwanger, Martin Peller, Robert Griessbach
The permanently increasing number of convenience and safety functions leads to higher complexity of in-car electronics and the rapidly growing amount of sensors, actuators and electronic control units places higher demands on high- speed data communication protocols. Safety-critical systems need deterministic protocols with fault-tolerant behavior. The need for on-board diagnosis calls for flexible use of bandwidth and an ever-increasing number of functions necessitates a flexible means of extending the system. None of the communication solutions available on the market until now (like CAN or TTP) have been able to fulfill all these demands. To solve these problems, BMW together with several semiconductor companies has developed a new protocol for safety-critical applications in automotive vehicles.
2016-11-16
Magazine
Focus on advanced safety systems and human-factor interventions The impact of REACH on the aviation sector Considered the most comprehensive chemical-regulation legislation to date, REACH presents serious ramifications for the aircraft industry. Lightweighting: What's Next? Experts weigh in on the challenges and future enablers in the battle to reduce vehicle mass. The best of COMVEC 2016 Autonomous vehicles and improved fuel efficiency via advanced powertrain solutions are pressing topics detailed in this select group of technical papers from the SAE Commercial Vehicle Engineering Congress. Optimizing waste heat recovery for long-haul trucks Autonomous solutions in agriculture Downsizing a HD diesel engine for off-highway applications Zero-emissions electric aircraft: Theory vs. reality
2012-04-11
Magazine
Putting CAE to work for non-experts CAE suppliers respond to the need to do more with less in a number of ways, including guided work flows and role-specific interfaces.
2012-01-25
Magazine
Alternative fuels heat up This is a rich time for combustion researchers. The need for better fuel efficiency and improved emissions has never been greater. New software model to help engine makers meet diesel soot standards Simulation enables engineers to predict particulate formation early in the design process.
2012-09-05
Magazine
Securing IT in the sky Along with IT systems and communication links comes IT security as a new factor when evaluating and monitoring the operational risk that needs to be managed during the operation of the aircraft. Data collection made easy Heavy vehicle makers, telematics providers strive to add more features while simplifying startup.
2011-08-17
Magazine
Bright prognosis for IVHM Partnerships, web tools help integrated vehicle health monitoring extend its reach.
2015-12-01
Magazine
Uncertainty quantification The technique is a must for next-generation simulation tools. Oil-pump sizing Researchers from Hinduja Tech investigate options for low friction and power consumption. The future of Indian commercial aviation The growth in traffic that airport modernization has supported has also made a significant contribution to the local and national economies, while the improved infrastructure has been positive for the perception of India in the global market. Driving EVs toward lower cost The race ison to reduce battery and electric-drive systems cost while improving efficiency. Powering on Rolls-Royce's Chief Engineer discusses new technologies that inspire current R&D design and evaluation work as part of its strategic roadmap for future big commercial programs. HMIs extend beyond the cab Telematic functions are being integrated into multi-function user interfaces.
2014-01-15
Magazine
Active safety starts in the pilot's seat Dassault Aviation's next-generation integrated digital avionics systems contribute to enhanced air safety in civil applications.
2015-02-02
Magazine
Wireless sensing--the road to future digital avionics A look at the comparative performance of wired and wireless sensors, type of wireless sensors & interfaces, frequency performance, protocols, network topologies and qualification standards. Testing reality in an increasingly complex design space Digital simulation tools have transformed the designing and testing of new airplanes, as well as the way they are manufactured and sustained.
2011-01-19
Magazine
More electric, more safe Advanced health-management technologies detect faults in early stages, providing an accurate health state and predicting the time-to-failures with high confidence.
2011-10-26
Magazine
An icy reception Next-generation propulsion systems for next-generation aircraft still have to address an (ice) age old problem.
2014-11-18
Magazine
Oil debris monitoring in aero engines In a gas turbine engine, small particles or "chips" are generated at the point of wear, serving as an advanced warning that catastrophic failure will occur if the wear is not addressed. Health monitoring systems, such as oil debris monitoring, are used to find these small particles so that the wear can be resolved before it's too late. Indigenous powertrain development Customer needs and expectations on drivability, fuel economy, and safety has pushed Indian and multinational OEMs to think about the development of powertrains and gearboxes for local needs with global standards. The next wave of crash simulation As computing speed has improved and software itself has made significant speed and performance gains with each release, modeling tools are now quick enough to build high-quality, large, high-detail vehicle models in a very efficient manner.
2009-11-11
Magazine
Watching wires A new FAA rule will require airlines to develop maintenance and inspection tasks to identify, correct, and prevent wiring conditions that introduce risk to continued safe flight.
2013-03-06
Magazine
Big fans gear up for new battles The big difference in newer commercial airplanes comes where it can't be seen: in the structure, in new materials, in the avionics, and most importantly, in the engines. Integrated Vehicle Health Management The aims of IVHM include improved safety through the use of diagnostics and prognostics to fix faults before they are an issue, as well as improve availability of fleets through better maintenance scheduling.
2017-01-24
WIP Standard
AIR7999
This SAE Aerospace Information Report (AIR) presents metrics for assessing the performance of diagnostic and prognostic algorithms applied to Engine Health Management (EHM) functions. This document consolidates and expands upon the metric information previously contained in AIR4985 and AIR5909. The emphasis is entirely on metrics and as such is intended to provide an extension and complement to such documents as ARP4176, which provides insight into how to create a cost benefit analysis to determine the justification for implementing an EHM system.
2017-05-03
WIP Standard
AIR6952
The pupose of this SAE AIR is to provide guidelines for sizing stored energy systems in use in emergency braking systems, in light of their intended purpose and applicable certification regulations.
2017-03-14
WIP Standard
AIR5317A
The SAE Guide to APU health management establishes the foundation for developing a successful APU health management program at any aircraft or APU operator, such as an airline, an OEM, an equipment supplier, or a military transport unit. This guide identifies the best practices for using an APU health management program to improve dispatch reliability and to satisfy Extended Operations (ETOPS) availability requirements.
2013-03-11
WIP Standard
AIR5567B
The scope of the test method is to provide stakeholders including fluid manufacturers, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This simple test is only designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions. It is not possible to set a general acceptance threshold oxidation limit based on this test method because carbon brake stack oxidation is a function of heat sink design and the operating envirnoment.
2013-04-24
WIP Standard
AIR6247
This document is intended to serve two purposes: (1) provide a list of topics for potential customers to ask of the facility to aid their selection decision-making, and (2) provide a list of icing wind tunnel and engine test stand facilities that simulate flight through icing or ice crystal clouds.
2016-05-17
WIP Standard
AIR6245
This document is applicable to military aircraft where stakeholders are seeking guidance on the development and approval of Structural Health Monitoring (SHM) technologies and on the integration of these technologies into encompassing maintenance and operational support systems. The document will refer to those guidelines prepared under SAE ARP6461 that are relevant and applicable to military applications.
2015-07-09
WIP Standard
AIR6341
The purpose of this AIR is to compile in one definitive source, commonly accepted calibration, acceptance criteria and procedures for simulation of Supercooled Large Droplet (SLD) conditions within icing wind tunnels. Facilities that meet the criteria for either some or all of the recognized conditions will have known SLD icing simulation capability.
2014-09-30
WIP Standard
AIR6334
This SAE Aerospace Information Report (AIR) examines the need for and the application of a power train usage metric that can be used to more accurately determine the TBO for helicopter transmissions. It provides a formula for the translation of the recorded torque history into mechanical usage. It provides examples of this process and recommends a way forward. This document of the SAE HM-1 IVHM Committee is not intended as a legal document and does not provide detailed implementation steps, but does address general implementation concerns and potential benefits.
2014-01-29
WIP Standard
AIR6292
The SAE Aerospace Information Report (AIR) is intended to be used as a process verification guide for evaluating implementation of key factors in bonded repair of fiber reinforced composite structure in a repair shop environment. The guide will be used in conjunction with a regulatory approved and substantiated repair, and is intended to promote consistency and reliability.
2013-10-31
WIP Standard
AIR6287
The purpose of this SAE Aerospace Information Report (AIR) is to provide information regarding the basic requirements for environmental effects of composite materials used in ULDs. Material variances related to raw materials and manufacturing processes is not part of this information, nor is damage tolerance.
Viewing 1 to 30 of 4568

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