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2015-09-27
Technical Paper
2015-01-2692
Giulia Garello, Niccolò Patron, Pietro Buonfico
Nature of braking friction is extremely complex and a deeper understanding of the physical mechanisms that govern the energy dissipation at the interface of friction pair is an important tool to create an even deeper knowledge of tribological behavior of friction material. Friction brakes need to transform kinetic energy into heat: a complete knowledge of thermal effects during this process in every brake component is an essential part of brake design. As referred to brake pads, the analysis of dyno testing data highlighted experimental evidences related to thermo-mechanical effects, such as the different wear resistance capabilities of material classes (NAO and Low Steel). Tribological characteristics are not constant under all testing conditions and they strongly depend on temperature being the direct consequence of kinetic energy dissipation. The aim of this work is to explain the relation between wear and energy for different type of friction materials.
2015-09-27
Technical Paper
2015-01-2694
Cheng Ruan, Lijun Zhang, Dejian Meng
Research Objective During light to moderate braking at high speed, the local high temperature phenomenon can be observed on the brake disc surfaces, known as hot spots. The occurrence of hot spots will lead to negative effects such as brake performance fade, thermal judder and local wear, which seriously affect the performance of vehicle NVH. In this paper, based on the bench test of a ventilated disc brake, the basic characteristics of hot spots is obtained and the evolution process of temperature field and disc deformation is analyzed in detail. Methodology A stop brake bench test under different initial speeds and brake pressures is completed on a Link Model 3900 brake dynamometer. The temperature field and deformation of the disc surface is obtained via inferred thermal camera and non-contact displacement sensors. The space distribution characteristic and time evolution characteristic of disc temperature field and deformation is analyzed.
2015-09-27
Technical Paper
2015-01-2670
Achim Reich, Dr. Angelo Sarda PhD, Dr. Martin Semsch PhD
Residual brake torque (RBT) is generated in disc brakes as a result of contact (dynamic friction) between brake disc and brake pads when the braking system is not actuated. Among the negative implications of RBT are, notably, dispensable additional fuel consumption as well as increased pad wear, which can also unfold as uneven along the pads` surfaces. The paper is based on extensive knowledge acquired through manifold measurement-based studies and contains a comprehensive assessment of the main topics related to the subject. Aiming to provide an overview about the motivation and importance of efforts to reduce RBT, effects on the environment as well as on consumption of resources are contemplated both within a general frame and for a number of selected specific cases.
2015-09-15
Technical Paper
2015-01-2546
Sylvain Delrieu
To perform a complete aircraft certification plan, civil aviation test centres use specific flight test installations and ground test means. In this scope tests specialists operate ground test means which have a generic name Laboratory Tests Means (LTM) to validate aircraft functions. Today these functions are becoming more and more complex, moreover certification deadlines and tests campaign costs are becoming increasingly challenging and demand LTM use optimization. In this context current LTM development approach is no longer suitable to cover these new constraints. Currently LTMs start to be designed when testing strategy for a new aircraft is defined and design is quite specific. Drawbacks of such an approach are: tunnel effect for LTM development, no simple sharing of testing resources, LTM reuse is not easy, LTM upgrade requires re-engineering and many LTMs have to be maintained even if only partially used.
2015-09-15
Technical Paper
2015-01-2553
Markus Dahlweid, Jörg Brauer, Jan Peleska
Model-based development is a well-established and widely used technique to design and implement systems by specifying the overall architecture of a system and its behavior directly in modeling tools such as Atego Modeler or Enterprise Architect. The next step forward in this process is using the same framework also for the design and specification of the tests for these systems. The RT-Tester MBT tool offers a novel approach to model-based embedded systems testing. Model-based Testing offers automated generation of test cases, test data and test procedures for model-in-the-loop, hardware-in-the-loop and system testing from UML/SysML models, which describe the intended system behavior. The presented approach offers a number of testing strategies, which can be used to tailor the generated test suites according to the indented criticality level.
2015-09-15
Technical Paper
2015-01-2548
Andreas Himmler
Hardware-in-the-loop (HIL) testing is regarded as the tried-and-tested method for function, component, integration and network tests for the entire system. It is indispensable in the software development process for control units and has been an integral part of numerous companies’ development process for years. This holds especially for model based design. Since all the time HIL testing is applied, users continuously optimized their processes. This reflects the need to adopt testing processes to changing conditions, which may be imposed by industry changes. A well-known fact is the division of tasks between different sites of a single company or between the system integrator and its suppliers. Thus, companies, departments or teams are often located in different buildings, towns or even countries. This division of tasks imposes a challenge for the integration testing of systems, since there are significant interdependencies between the controls of aircraft systems.
2015-09-06
Technical Paper
2015-24-2517
Piotr Bielaczyc, Joseph Woodburn, Andrzej Szczotka
The particulates in vehicular exhaust are now under great scrutiny and are subject to legislative limits in many cases. In the EU, direct injection spark ignition (DI SI) engines running on petrol now have limits for particulate emissions set for both mass and number. It is widely acknowledged that current legislative laboratory test procedures in many ways represent a best-case scenario – more aggressive driving cycles and less favourable ambient conditions can increase particulate emissions massively. Ambient temperature is generally the environmental parameter of most importance regarding particulate emissions from an engine, particularly for the reasonably brief periods of operation typical for passenger cars operating from a cold start. Cold start events are challenging for internal combustion engines for various reasons, with multiple emissions impacts for all types of automotive engines.
2015-09-06
Technical Paper
2015-24-2510
Jan Czerwinski, Pierre Comte, Martin Güdel, Andreas Mayer, Jacques Lemaire, Felix Reutimann, Adm Heinz Berger
As a result of increased use of catalytic exhaust aftertreatment systems of vehicles and the low-Sulfur Diesel fuels there is an increasing share of NO2 in the ambient air of several cities. This is in spite of lowering NOx. NO2 is much more toxic than NO and it will be specially considered in the next legal testing procedures. There are doubts about the accuracy of analyzing the reactive substances from diluted gas and this project has the objective to show how NO2 is are changing along the gas way of the exhaust- and the CVS systems. For legal measurements of NO2 a WLTP-DTP subgroup proposed different combinations of NOx-analyzers and analysis of NO and NOx. Some of these setups were tested in this work. The investigated WLTP – NO2-measuring methods have been found as useful tools to estimate the NO2-levels and there were no indications of reactivity at these low concentration levels.
2015-09-06
Technical Paper
2015-24-2504
Gerben Doornbos, Emma Adams, Per-Anders Carlsson, Daniel Dahl, Mats Laurell, Håkan Schyllander, Par Gabrielsson, Milica Folic, Ingemar Denbratt, Magnus Skoglundh
Commercial three way catalysts have limited capacity towards reducing NOx in the presence of excessive oxygen. This prevents lean-burn combustion concepts from meeting legislative emission standards. A solution towards decreasing NOx emissions in the presence of excess air is the use of a passive-SCR system. Under rich conditions ammonia is formed over an ammonia formation catalyst, the ammonia is stored in the SCR and in its turn reacts with the NOx under lean engine conditions. Here up-scaled Pt/Al2O3 and Pd/Al2O3 catalysts as well as a commercially Pd-Rh based three-way catalyst (TWC) are evaluated using both engine and further lab-scale tests. The purpose of these tests is to compare the ammonia production for the various catalysts under various lambda values and temperatures by means of engine and lab scale tests. The Pd/Al2O3 showed little sensitivity to temperature both under engine and lab scale experiments.
2015-09-06
Technical Paper
2015-24-2509
Maria Vittoria Prati, Giovanni Meccariello, Livia Della Ragione, Maria Antonietta Costagliola
The aim of this study is to investigate the parameters influencing the real driving emission monitoring with particular attention towards the influence of road gradient. For this purpose, an experimental activity was carried out with a Euro 5 diesel light-duty vehicle, driven along two tracks of Naples characterized by different road gradient: the first pattern is quite flat, the second is in an area with variable altitude and includes positive (+2.9%) and negative (-3.6%) road gradient. Exhaust emissions of CO, THC, NOx, CO2 were acquired on road by using a portable emission measuring system (PEM) connected also to the Engine Control Unit for saving the main engine parameters and a GPS for the geographical coordinates and altitude. The acquired speed profiles were repeated on the chassis-dynamometer without simulating the road gradient.
2015-09-06
Technical Paper
2015-24-2391
Dimitris Tsokolis, Stefanos Tsiakmakis, Georgios Triantafyllopoulos, Anastasios Kontses, Zisis Toumasatos, Georgios Fontaras, Athanasios Dimaratos, Biagio Ciuffo, Jelica Pavlovic, Alessandro Marotta, Zissis Samaras
The present paper describes the development of a standardized modelling approach to simulate the effect of the new Worldwide harmonised Light duty Test Procedure (WLTP) on the certified CO2 emissions of light duty vehicles. The European fleet has been divided into a number of representative segments based on specific vehicle characteristics and technologies. Representative vehicles for each segment were chosen. A test protocol has been developed in order to generate the necessary validation data for the simulation models which were developed subsequently. A standardized modelling procedure was adopted, in order to minimize the flexibilities and sources of uncertainty, which was based on the development of a reference "template model" to be used in the study. Subsequently, vehicle models were developed using AVL Cruise simulation software based on the abovementioned template model.
2015-09-06
Technical Paper
2015-24-2524
José Lujan, José V. Pastor, Héctor Climent, Manuel Rivas
On actual gasoline turbocharged engines it is common to use a compressor by-pass valve in order to solve the compressor surge problem when the throttle pedal position is released and closes rapidly. The paper deals with a methodology based on experiments to measure the discharge coefficient of an integrated compressor by-pass valve, to understand the possible difference between the steady flow test bench and turbocharger test bench discharge coefficient measurements. To determine if there is some compressor outlet flow field influence due to compressor blades rotation that could modify the discharge coefficient measurement, compared to the steady flow test bench measurements, a fully instrumented turbocharger was used to measure the difference between steady flow test bench and turbocharger test bench discharge coefficients results. Effects of different boundary conditions on turbocharger test bench tests and how they affect the discharge coefficient measurement are also presented.
2015-07-28
Standard
J1699/3_201507
The main purpose of this Recommended Practice is to verify that vehicles are capable of communicating a minimum subset of information, in accordance with the diagnostic test services specified in SAE J1979: E/E Diagnostic Test Modes, or the equivalent document ISO 15031-5: Communication Between Vehicle and External Equipment for Emissions-Related Diagnostics – Part 5: Emissions-related diagnostic services. Any software meeting these specifications will utilize the vehicle interface that is defined in SAE J2534, Recommended Practice for Pass-Thru Vehicle Programming.
2015-07-22
Standard
J551/17_201507
This SAE Standard specifies the test methods and procedures for testing passenger cars and commercial vehicles to magnetic fields generated by power transmission lines and generating stations. SAE J551-1 specifies general information, definitions, practical use, and basic principles of the test procedure.
2015-07-17
Standard
AS1284B
The test procedure and related limit value are intended to apply to fixed and mobile ground pressure fuel dispensing sytems and to aerial refueling tankers.
2015-07-01
Standard
J1726_201507
This SAE Recommended Practice provides test methods and criteria for evaluating the internal cleanliness and air leakage for engine charge air coolers. This SAE Recommended Practice also provides nomenclature and terminology in common use for engine charge air coolers, related charge air cooling system components, and charge air cooling system operational performance parameters.
2015-06-30
Standard
J1808_201506
This document applies to direct acting vacuum power assist brake boosters only, exclusive of the master cylinder or other brake system prime mover devices for passenger cars and light trucks [4500 kg GVW (10 000 lb)]. It specifies the test procedure to determine minimum performance and durability characteristics.
2015-06-19
Standard
J860_201506
This SAE Standard is used to determine the mass per unit area, in grams per square meter, of materials used for trimming automobile interiors.
2015-06-15
Technical Paper
2015-01-2213
John Van Baren
Abstract Random vibration control systems produce a PSD plot by averaging FFTs. Modern controllers can set the Degrees of Freedom (DOF), which is a measure of the amount of averaging to use to estimate the PSD. The PSD is a way to present a random signal-which by nature “bounces” about the mean, at times making high excursions from the mean-in a format that makes it easy to determine the validity of a test. This process takes time as many frames of data are collected in order to generate the PSD estimate, and a test can appear to be out of tolerance until the controller has enough data to estimate the PSD with a sufficient level of confidence. Something is awry with a PSD estimate that achieves total in-tolerance immediately after starting or during level changes, and this can create dangerous over or under test conditions within specific frequency bands and should be avoided.
2015-06-15
Technical Paper
2015-01-2116
Peter Struk, Tadas Bartkus, Jen-Ching Tsao, Tom Currie, Dan Fuleki
Abstract This paper presents measurements of ice accretion shape and surface temperature from ice-crystal icing experiments conducted jointly by the National Aeronautics and Space Administration (NASA) and the National Research Council (NRC) of Canada. The data comes from experiments performed at NRC's Research Altitude Test Facility (RATFac) in 2012. The measurements are intended to help develop models of the ice-crystal icing phenomenon associated with engine ice-crystal icing. Ice accretion tests were conducted using two different airfoil models (a NACA 0012 and wedge) at different velocities, temperatures, and pressures although only a limited set of permutations were tested. The wedge airfoil had several tests during which its surface was actively cooled. The ice accretion measurements included leading-edge thickness for both airfoils. The wedge and one case from the NACA 0012 model also included 2D cross-section profile shapes.
2015-06-15
Technical Paper
2015-01-2118
Sergey Alekseyenko, Michael Sinapius, Martin Schulz, Oleksandr Prykhodko
Abstract The results of experimental investigation of the icing processes of NACA 0015 airfoil are presented. The experiments have been carried out with the help of a high-speed camera at the icing/deicing facility at the Institute of Adaptronic and Functional Integration of the Technical University of Braunschweig. The investigation objective is the study of interaction between supercooled large droplets and the icing airfoil surface as well as physical phenomena occurring during the icing process. Evolution of the initial phase of ice growth process over time is observed, the general structure of ice accretion and its alteration along the airfoil is examined. Experiments have been carried out within a wide temperature range. Photos of the specific moments of the icing process have been analyzed. Splashing events and water movement on the icing surface have been observed.
2015-06-15
Technical Paper
2015-01-2125
Dan Fuleki, Jennifer L.Y. Chalmers, Brian Galeote
This paper describes the equipment, analysis methods and results obtained for particle size measurements based on a particle imaging velocimetry (PIV) system in which a short duration laser pulse is used to backlight airborne particles. This produces high quality and high resolution images of fast moving airborne particles in a non-intrusive manner. This imaging technique is also used to examine particle morphology and 2D particle trajectory and velocity. The image analysis methods are outlined and validation test results discussed which show the measurement of reference glass beads between 20 and 400 microns were generally to within their stated size. As well, validation testing using known icing wind tunnel droplet distributions were compared with Spraytek 2000 Malvern droplet size measurements and showed agreement of the MVD's to be within ±5% for distributions having nominally 20, 40 and 80 micron MVD's.
2015-06-15
Technical Paper
2015-01-2247
Masao Nagamatsu
Abstract The sound localization methods are used for detection of noise source locations of prototypes of mechanical products including automobile engines. There are several types of sound localization methods. In middle frequency around 1kHz, which is most sensitive frequency for human auditory, these sound localization methods have enough resolution in their reconstructed images, and they are effective to localize the sound sources. For high frequency sound localization, the holographic type methods take long time in its measurement. To overcome this problem, I have developed a converted method of Nearfield Acoustic Holography (NAH) method, which is one of conventional holographic sound localization method. However, in low frequency, all holographic localization methods do not have enough resolution in reconstructed images. I am now developing new sound localization method, Double Nearfield Acoustic Holography (DNAH) method.
2015-06-15
Technical Paper
2015-01-2292
Xiaorui Lu, Junda Ma
Abstract Over recent years, NVH refinement of engine is becoming increasingly important in buying decision and can significantly give competitive edge to the vehicle in market place. This paper deals with the development phase of a prototype engine in which a specific testing activity was carried out to improve the overall NVH behavior of the powertrain. In order to explain the optimization process in detail, a case study was described in this paper. First, NVH targets of the engine were set via benchmark tests on existing competitive products. Then series of baseline tests, such as 1M sound pressure level test and noise source identification, were performed on the engine. Test results indicated that an obvious breathing vibration mode exist near the intake manifold, which radiates high level noise. In order to achieve the NVH targets, a correlation validation was performed to find out the main reason that caused the vibration of intake manifold.
2015-06-15
Technical Paper
2015-01-2278
Rohit Ravindran, Debajit Das, Keval Kamani, P Sivaraman, Gyan Arora
Abstract Torsional vibration is a characteristic phenomenon of automotive powertrains. It can have an adverse impact on powertrain related noise as well as the durability of transmission and drivetrain components. Hence minimizing torsional vibration levels associated with powertrains has become important. In this context, accurate measurement and representation of angular acceleration is of paramount importance. A methodology was developed for in-house vehicle level torsional vibration measurement, analysis and representation of results. The evaluation of torsional vibration has two major aspects. First, the acquisition of raw rotational data and secondly, the processing of acquired data to arrive at usable information from which inferences and interpretations can be made about the behavior of the rotating element. This paper describes the development process followed for establishing a torsional vibration evaluation methodology.
2015-06-15
Journal Article
2015-01-2189
Michael Krak, Jason Dreyer, Rajendra Singh
Abstract Many powertrain structural sub-systems are often tested under steady state conditions on a dynamometer or in a full vehicle. This process (while necessary) is costly and time intensive, especially when evaluating the effect of component properties on transient phenomena, such as driveline clunk. This paper proposes a laboratory experiment that provides the following: 1) a bench experiment that demonstrates transient behavior of a non-linear clutch damper under non-rotating conditions, 2) a process to efficiently evaluate multiple non-linear clutch dampers, and 3) generates benchmark time domain data for validation of non-linear driveline simulation codes. The design of this experiment is based on a previous experimental work on clunk. A commercially available non-linear clutch damper is selected and the experiment is sized accordingly.
2015-06-15
Journal Article
2015-01-2285
Arne Nykänen, David Lennström, Roger Johnsson
Abstract Subjects who are well aware of what to judge commonly yield more consistent results in laboratory listening tests. This awareness may be raised by explicit instructions and training. However, too explicit instructions or use of only trained subjects may direct experiment results in an undesired way. An alternative is to give fairly open instructions to untrained subjects, but give the subjects a chance to get familiar with the product and context by, for example, riding a representative car under representative driving conditions before entering the laboratory. In this study, sound quality assessments of interior sounds of cars made by two groups were compared. In one group subjects were exposed to the same driving conditions that were later assessed in a laboratory listening test by taking them on a ride in one of the cars to be assessed, just before entering the laboratory. In the other group subjects made the laboratory assessments without prior car riding.
2015-06-15
Journal Article
2015-01-2281
Shrirang Deshpande, Randall Allemang
Abstract Spectral maps and order tracks are tools which are susceptible to improper sensor location on rotating machinery and to measurement noise. On a complex/large rotating system, the major behavior in a particular direction cannot be observed by using standard digital signal processing averaging techniques on different sensor outputs. Also, measurement noise cannot be reduced by applying averaging - due to the slew rate of the system. A newly developed technique tested on experimental data, is presented which uses singular value decomposition (SVD) as its basis to improve the observability of rotating systems. By using data acquired from multiple accelerometers on a machine, singular values - obtained from a SVD of the cross-power matrix at each 2-D point in the frequency-RPM domain - can be plotted in a color-map format similar to a RPM spectral map.
2015-06-12
Standard
AIR6282
This standard provides a cross reference detailing current test methods used in the qualification processes of fiber optic connectors, termini and cables for aerospace, telecommunications and naval applications. The cross-reference allows the end user to select the test methods most suitable for qualifying a component, or to identify alternative test methods where a specific test is not defined in a referenced document. The standard also provides information on what area each type of referenced document has been developed for.
2015-05-29
Standard
ARP986D
This SAE Aerospace Recommended Practice (ARP) defines recommended analysis and test procedures for qualification of pneumatically, electrically, manually, and hydraulically actuated air valves. They may be further defined as valves that function in response to externally applied forces or in response to variations in upstream and/or downstream duct air conditions in order to maintain a calibrated duct air condition (e.g., air flow, air pressure, air temperature, air pressure ratio, or air shutoff). Qualification testing performed on the airplane to verify compatibility of the valve function and stability as part of a complete system is outside the scope of this document. Refer to ARP1270 for design and certification requirements for cabin pressurization control system components. As this document is only a guide, it does not supersede or relieve any requirements contained in detailed Customer specifications.
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