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Technical Paper
2014-06-30
Jan Hendrik Elm, Jens Viehöfer, Jan-Welm Biermann
Abstract The automotive industry permanently enhances Downsizing concepts due to environmental commitments and energy consumption concerns. Even in the category of city- and supermini-cars, great efforts are made for the development of highly charged engines with small displacement. So far the main focus of these developments is set on the reduction of CO2 emissions and fuel consumption. However these are not the only aspects, which have to be fulfilled by the vehicle in order to meet the demands of the customers and to be successful in competition. The NVH characteristics of such Downsizing vehicles have to match a class-specific level, which can only be achieved by additional measures. Regarding this, a view of the dynamic behavior of the entire vehicle is required. At the Institut für Kraftfahrwesen Aachen (ika) the potential for reducing fuel consumption and CO2 emissions of a Downsizing concept is investigated using a city-car as reference. For this purpose, among other things, the three-cylinder-engine of the reference car is replaced by a highly charged two-cylinder-engine with same power output but smaller displacement.
Technical Paper
2014-06-30
Raimo Kabral, Lin Du, Mats Åbom, Magnus Knutsson
Abstract Current trends for IC-engines are driving the development of more efficient engines with higher specific power. This is true for both light and heavy duty vehicles and has led to an increased use of super-charging. The super-charging can be both in the form of a single or multi-stage turbo-charger driven by exhaust gases, or via a directly driven compressor. In both cases a possible noise problem can be a strong Blade Passing Frequency (BPF) typically in the kHz range and above the plane wave range. In this paper a novel type of compact dissipative silencer developed especially to handle this type of problem is described and optimized. The silencer is based on a combination of a micro-perforated (MPP) tube backed by a locally reacting cavity. The combined impedance of micro-perforate and cavity is chosen to match the theoretical optimum known as the Cremer impedance at the mid-frequency in the frequency range of interest. Due to the high damping achieved at the Cremer optimum (hundreds of dB/m) it is easy to create a compact silencer with a significant damping (say > 30 dB) in a range larger than an octave.
Technical Paper
2014-06-30
Rebecca Cowles, Andrew Shives, Daniel Rauchholz
Abstract To satisfy the increased expectations of customers, engineers are challenged to increase fuel economy while also improving noise, vibration, and harshness (NVH) performance. In order to improve fuel economy, engine compartment designs have become more compact with reduced air flow. Elevated temperatures caused by these designs can degrade the durability and acoustic performance of the fibrous acoustic insulator material. A typical method for protecting insulators from elevated temperatures is to apply an aluminum foil patch to the surface. However, foil patches can restrict the insulator's ability to absorb sound and can be difficult to apply to complex part shapes. Foil patches can be perforated to allow the insulator to absorb sound, but there is a cost penalty as well as potential for long term performance degradation due to blocked perforations. Since NVH targets are also increasing, it's important to maximize the benefit of each part. Given these performance challenges, a heat reflective coating (HRC) has been developed as a cost effective alternative to perforated foils.
Technical Paper
2014-06-30
Koen Vansant, Hadrien Bériot, Claudio Bertolini, Giuseppe Miccoli
Abstract As the legislation for pass-by noise (PBN) has recently become more stringent, car manufacturers face again a challenging task to reach the new SPL objective (70dB(A)). A good design of the engine bay is therefore required to sufficiently attenuate the noise coming from sources as the engine and the intake. This involves proper design of the engine bay's panels including apertures, and a good selection of the type and location of acoustic treatments. For a given engine bay design, the PBN SPL results can be obtained with a PBN test or by an equivalent simulation. Using simulation models it is possible to create the perfect test environment virtually and moreover to obtain acoustic results for a large number of designs upfront of any actual testing or prototype. The challenge for simulation models is however that, as the results should typically be available from 20 Hz up to 4 or 5 kHz and overall SPL results should be retrieved from a narrow band response over this large frequency range, the CAE models required can become very large and many frequencies need to be computed resulting in long solving times.
Article
2014-06-20
Omega’s PR-21 series of RTD (resistance temperature detector) sensors with M12 connector feature a welded 316L stainless steel housing and an integral 4-pin M12 connector for easy connection.
Article
2014-06-12
The cause of the issue was an error in the process Ford engineers used to correlate wind-tunnel testing into their Total Road Load Horsepower (TRLHP) factor that is key to the vehicle fuel economy models that are ultimately submitted to the U.S. EPA.
Article
2014-06-11
Reaction Design worked with a German premium automotive company to build cylinder-combustion simulations for a high-performance diesel engine with the goal of accurately and quickly predicting combustion performance and the effects of varied operating conditions on soot emissions.
Standard
2014-06-06
Description of Material—The materials classified under this specification are: a. Mastic vibration damping materials used to reduce the sound emanating from metal panels. b. Mastic underbody coatings used to give protection and some vibration damping to motor vehicle underbodies, fenders, and other parts.
Article
2014-06-03
The LC411-USBH series high-speed USB load cells from Omega connect directly to your computer and offer up to 1000 readings per second.
Article
2014-05-31
Hexagon Metrology’s Leica T-Scan 5 handheld system for laser trackers is said to operate more than 15 times faster than the previous model.
Article
2014-05-30
PCB Piezotronics’ surface microphone for R&D testing features a low-profile design ideal for testing in confined spaces and windy environments.
Article
2014-05-30
Supercritical Fluid Technologies’ SFT-250 supercritical fluid extractor is designed to perform extractions in supercritical fluid and meets the rigors of the research lab.
Article
2014-05-20
ViCANdo from Zuragon is a multimedia software tool for development, physical testing, and validation of various applications such as vehicle fleets, hybrid-electric systems, active safety systems, autonomous vehicles, and HMI systems.
Standard
2014-05-16
This SAE Recommended Practice sets forth the instrumentation, environment, and test procedures to be used in measuring the silencer system effectiveness in reducing intake or exhaust sound level of internal combustion engines. The system shall include the intake or exhaust silencer, related piping, and components. This procedure is intended for engine-dynamometer testing and is not necessarily applicable to vehicle testing (see Appendix A). The effect of the exhaust or intake system on the sound level of the overall machine must be determined using other procedures. This procedure may be successively applied to various silencer configurations to determine relative effectiveness for that engine. Insertion loss for individual silencers may be calculated through measurement of the silenced and unsilenced system.
Standard
2014-05-16
This SAE Recommended Practice sets forth the equipment, environment, and test procedures to be used in measuring sound levels of engines. The purpose is to provide a uniform method of measuring the maximum acoustical radiation from the exterior surfaces of an engine under representative engine operating conditions. The measured sound levels will be useful in development of engines, comparison of engines, and installation of engines in various applications. The correlation of the measured engine sound levels to the various application sound levels will have to be developed.
Standard
2014-05-16
This procedure provides for the measurement of the sound generated by a test tire, mounted on a single-axle trailer, operated at multiple speeds. The procedure describes test practices for both United States and International practices. Specifications for the instrumentation, the test site, and the operation of the test apparatus are set forth to minimize the effects of extraneous sound sources and to define the basis of reported sound levels.
Standard
2014-05-16
This SAE Recommended Practice establishes a rating scale for subjective evaluations of noise and discomfort in motor vehicles. Through test procedures utilizing specific vehicles on specific roads, the scale may be utilized to assess the relative contributions of tires to noise and discomfort. The noise and ride comfort characteristics attributed to automotive tires have traditionally been estimated by subjectively assigning number designations (commonly on a 1 to 10 scale) to the audible and tactile sensations observed while traversing a given road course in a vehicle equipped with the tires under evaluation. Regardless of advances in objective measurements of tire properties related to noise and discomfort, subjective evaluation will continue to be necessary for the purpose of establishing the significance of such measurements. The rating scale of this recommendation is applicable to assessment of each of the wide variety of audible and tactile disturbances referred to by such terms as bump, thump, slap, shake, etc.
Article
2014-05-14
Michael Duoba (SAE Member, 1993), Vehicle Test Engineer and team leader for the Advanced Powertrain Research Facility at Argonne National Laboratory, discuss his career progression and the type of work conducted at his lab.
Technical Paper
2014-05-09
Nikolina Samardzic
Values of the speech intelligibility index (SII) were found to be different for the same speech intelligibility performance measured in an acoustic perception jury test with 35 human subjects and different background noise spectra. Using a novel method for in-vehicle speech intelligibility evaluation, the human subjects were tested using the hearing-in-noise-test (HINT) in a simulated driving environment. A variety of driving and listening conditions were used to obtain 50% speech intelligibility score at the sentence Speech Reception Threshold (sSRT). In previous studies, the band importance function for ‘average speech’ was used for SII calculations since the band importance function for the HINT is unavailable in the SII ANSI S3.5-1997 standard. In this study, the HINT jury test measurements from a variety of background noise spectra and listening configurations of talker and listener are used in an effort to obtain a band importance function for the HINT, to potentially correlate the calculated SII scores with the measured speech intelligibility scores.
Technical Paper
2014-05-09
David Lennström, Roger Johnsson, Anders Agren, Arne Nykänen
In the vehicle development process, targets are defined to fulfill customers' expectations on acoustic comfort. The interior complete vehicle acoustic targets can be cascaded down to system and component targets, e.g. insulation properties and source strengths. The acoustic transfer functions (ATFs) from components radiating airborne noise play a central role for the interior sound pressure levels. For hybrid vehicles fitted with an electric traction motor, the contribution of high frequency tonal components radiated from the motor housing needs to be controlled. The interior sound pressure due to an airborne motor order can be estimated by surface velocities and ATFs. This study addresses the ATFs measured from a large number of positions located around an electric rear axle drive (ERAD) and their influence on estimated interior noise. First, the magnitude variation between the individual ATFs and how it clearly can be visualized was presented. Displaying all ATFs in a color map revealed the magnitude at each geometrical location of the respective microphone.
Article
2014-05-08
The first ever Airbus A350 XWB to visit the U.S., MSN2, arrived the second week in May at McKinley Climatic Lab at Eglin Air Force base in Florida. Over several weeks the aircraft and its various systems and cabin installations will be subjected to the extreme hot and cold temperatures that the facility can sustain in a testing environment.
Article
2014-05-08
CSEG has designed, and filed a patent for, a cooling pack and fan that would allow for extreme driving conditions while downsizing the cooling pack, increasing fuel economy, and reducing costs for the OEM as well as the customers who do the driving.
Technical Paper
2014-05-05
Lindsay J. Miller, Susan Sawyer-Beaulieu, Edwin Tam
Polyurethane (PU) foam is used for many automotive applications with the benefits of being lightweight, durable, and resistant to heat and noise. Applications of PU foams are increasing to include non-traditional purposes targeting consumer comfort. An example of this is the use of PU foam between the engine and engine cover of a vehicle for the purpose of noise abatement. This addition will provide a quieter ride for the consumer, however will have associated environmental impacts. The additional weight will cause an increase in fuel consumption and related emissions. More significant impacts may be realized at the end-of-life stage. Recycling PU foams presents several challenges; a lack of market for the recyclate, contamination of the foams, and lack of accessibility for removal of the material. PU foam pieces are likely to end up being landfilled after the vehicle is shredded, negating the benefit of choosing this material for its recyclability over another non-recyclable material.
WIP Standard
2014-04-30
This SAE Recommended Practice is applicable to all liquid-to-gas, liquid-to-liquid, gas-to-gas, and gas-to-liquid heat exchangers used in vehicle and industrial cooling systems. This document outlines the test to determine durability characteristics of the heat exchanger from vibration-induced loading.
WIP Standard
2014-04-30
This SAE Recommended Practice provides procedures, and information to conduct vibration (impact) tests on lighting devices and their components as well as other safety equipment used on vehicles.
Article
2014-04-28
AB Dynamics’ updated suspension parameter measuring machine (SPMM), the SPMM5000, is a fixed ground plane kinetics and compliance test machine that measures suspension parameters and characteristics like the SPMM4000 on which it is based.
Technical Paper
2014-04-28
Y. S. Thipse
Abstract Designers and analysts need to compare and conduct synthesis for selection of materials based on their properties involving simulation, optimization and correlation with test data. An example is that of acoustic material properties such as random and normal incidence sound absorption coefficient and sound transmission loss. The international test standards necessitate having standard operating procedures for characterization of these materials. This procedure is quite involved and addresses steps including test data acquisition, post processing, calculations, classification, report generation and most importantly, storage of such innumerable material properties in a structured manner to facilitate ease of retrieval and updating of properties. It is also highly desirable to have a synergy of the databank directly with simulation tools. Further, all of these steps need to be accurate, non-speculative and quick. In order to address all these diverse requirements, three cases of powerful knowledge based utilities are hereby presented.
Article
2014-04-23
In a bid to deliver a system that combines quality control with process control, Hexagon introduces its 360° Smart Inline Measurement Solutions for automotive applications.
Article
2014-04-21
Ashcroft pressure switches offer a selection of features to meet the requirements of most industrial applications.
Article
2014-04-16
Champion GSE has developed a dual-purpose stand for its -1B and -2B GEnx engine platforms.
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