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Viewing 1 to 30 of 14566
2015-06-15
Technical Paper
2015-01-2149
Caroline Laforte, Caroline Blackburn, Jean Perron
Ideally, an icephobic coating applied to ice-exposed surfaces appears to be an interesting solution to prevent ice build-up. Over the last decade, developments of efficient icephobic coatings were multiplied. Some materials that reduce ice adhesion have been developed from which the ice can be more easily shed, possibly even with existing forces such as wind, gravity and vibrations. This paper will depict icephobic coating performances of 262 different coatings and 11 grease type substrates tested over the past 10 years at the Anti-Icing Materials International Laboratory (AMIL). Since 2003, the icephobic performance is evaluated with two main test methods. A first test method was developed in regards to measuring the ice adhesion and its reduction. A second test was then developed to measure the ice accumulation reduction.
2015-06-15
Technical Paper
2015-01-2200
Guojian Zhou, Xiujie Tian, Keda Zhu, Wei Huang, Richard E. Wentzel, Melvyn J. Care
Acoustic performance of auto interiors is definitely important to control the NVH performance inside a vehicle, and it is determined by the material parameters (porosity, air flow resistance, tortuosity, viscous characteristic length, thermal characteristic length, density, Young’s modulus, Poisson’s ratio, damping coefficient, and thickness). First, by making different felt samples (of different surface density and thickness), the acoustic performance and related parameters were obtained. Then the correlation between the parameters and the acoustic performance was summarized, and the sensitivity of different parameters on the acoustic performance was demonstrated. Through this method material parameter database can be established based on real materials and together with the sensitivity analysis sound package design and adjusting can be easily conducted.
2015-06-15
Technical Paper
2015-01-2076
Caroline Laforte, Neal Wesley, Marc Mario Tremblay
In North America, about ten million kilograms of runway deicers are applied on airport runways to ensure safe takeoffs and landings of aircraft in adverse conditions. Although some of the chemicals are recovered, much of them are dispersed through aviation operations to airport’s surrounding environment. Little focus has been given into assessing and determining optimal quantities of deicers to be used on runways, that at the same time retain a high degree of safety, while reducing risks to the environment and improving airport efficiencies. Improved deicer performance tests would allow for the development of more environmentally sustainable deicers, through their improved performance. A better assessment of their deicing and anti-icing performance along with their degree of skid resistance on runway pavement, will help in the development of the next generation of runway de/anti-icing chemicals to ensure improved sustainable and safe aircraft takeoffs and landings.
2015-06-15
Technical Paper
2015-01-2206
Glenn Yin, Alan Parrett, Nitish Wagh, Dennis Kinchen
In automotive noise control, the hood liner is an important acoustic part for mitigating engine noise. The random incidence absorption coefficient is used to quantify the component level acoustic performance. Generally, air gaps, type of substrate materials, density of the substrate materials and Air Flow Resistivity of the material or cover scrim are the dominant control factors in the sound absorption performance. This paper describes a systematic experimental investigation of how these control factors affect the part performance. The first stage of this study is based on current available solutions from sound absorber suppliers, the acoustic absorption of different hood liner constructions, with variations in materials, density, air gaps, and scrims were measured. Next, hood liners with these different constructions were installed in a vehicle, and Sound Power Based Noise Reduction (PBNR) from the engine compartment to the interior was measured to quantify in-vehicle effects.
2015-06-15
Technical Paper
2015-01-2210
Quan Wan
Five parameters are often used in acoustic modeling of porous absorption material, which are air flow resistivity σ, porosity φ, tortuosity α∞, viscous characteristic lengths Λ and thermal characteristic length Λ’. These parameters are not easy to be directly measured with high precision, especially the latter three parameters. FOAM-X is the software capable of identifying indirectly these parameters from impedance tube test results by virtue of Johnson-Champoux-Allard model, so becomes increasingly popular. However, its stability of parameter identification is rarely reported. This paper studies the factors to disturb the stability of FOAM-X on those porous absorption materials generally applied in vehicle interior trim (pure PET fiber, shoddy, PP/PET double-component fiber), such as the number of known parameters in advance, the frequency range, the vacuum bulk density, and so on.
2015-06-15
Technical Paper
2015-01-2208
David Stotera, Scott Bombard
Both vehicle roof systems and vehicle door systems typically have viscoelastic material between the beams and the outer panel. These materials have the propensity to affect the vibration decay time and the vibration level of the panel with their damping and stiffening properties. Decay time relates to how pleasant a vehicle door sounds upon closing, and vibration level relates to how loud a roof boom noise may be perceived to be by vehicle occupants. If a surrogate panel could be used to evaluate decay time and vibration level, then a design of experiments could be used to compare the effects of different factors on the system. The factors were varied in laboratory tests, and the results were calculated using design of experiments software. In this paper the results of a study of the varying factors tested with respect to their effects on decay time and vibration level are presented, as well as the effect the results had on potential optimization of the systems.
2015-06-15
Technical Paper
2015-01-2341
Marc Ingelmann, Holger Bickelmann
BASF supplies the automotive industry with parts made of the Micro-cellular Polyurethane Elastomer - Cellasto®, a material with unique characteristics in NVH applications. For over 50 years our automotive customers are relying on our materials, with the Jounce Bumper being our best known applications. Top mounts and coil-spring-isolators are also a key offering to the industry. A lot of functions in automotive and non-automotive products are using Cellasto® as damping element, such as armrests, seats, torque-dampers, handheld machines etc. The dynamic performance of Cellasto , combined with the ability to work in limited packages, makes it the ideal choice. The amplitude selective damping fits to the automotive requirements: small amplitudes are generating a low damping of the material; high amplitudes are increasing the damping.
2015-06-15
Technical Paper
2015-01-2340
Stephen J. Bennison, Steven M. Hansen, Jingjing Xu PhD, Yuki Shitanoki PhD
Reduction of glazing weight in automobiles is now a distinct possibility due to the commercial availability of relatively thin glass (< 2 mm) of suitable quality. However, thinning down the glass inevitably leads to reductions in structural performance and sound barrier properties, hence making the design of lightweight vehicle glazing elements problematic. It is well recognized that laminated glass, where two or more plies of glass are bonded by a tough, transparent polymer, may be used to improve the acoustic barrier performance of glazing elements. Improvements in acoustics often come with a reduction in laminate stiffness and associated load bearing capability. In this contribution we demonstrate that these two conflicting requirements: acoustics and stiffness (strength) may be balanced and optimized through the use of new polymer and film technology.
2015-06-15
Technical Paper
2015-01-2345
Arnaud Duval, Valérie Marcel, Ludovic Dejaeger, Francis Lhuillier, Moussa Khalfallah
The Flaxpreg™ is a green and light very long flax fibers thermoset reinforced sandwich, that can be effectively used as multi-position trunk loadfloor or structural floor in the passenger compartment of a vehicle. The prepreg FlaxTapes© of about 120 g/m² constituting the skins of the sandwich, are unidirectionally aligned flax fibers tapes, with acrylic resin here, easily manipulable without requiring any spinning or weaving step and thus without any negative out of plane crimping of the almost continuous flax fibers. Thank to their very low 1,45 density combined with an adaptative 0°/90°/0° orientation of the FlaxTapes© (for each skin) depending on the loading boundary conditions, the resulting excellent mechanical properties allow a – 35% weight reduction compared to petro-sourced Glass mat/PUR sandwich solutions (like the Baypreg).
2015-06-15
Technical Paper
2015-01-2343
Jian Pan, Yuksel Gur
OEMs are racing to develop light weight vehicles as government regulations now mandate automakers to nearly double the average fuel economy of new cars and trucks by 2025. Light weight materials such as aluminum, magnesium and carbon fiber composites are being used as structural panels in vehicle body. The reduction in weight in structural panels increases noise transmission into passenger compartment. This poses a great challenge in sound package development since simply increasing weight in sound package components to reduce interior noise is no longer an option. This paper discusses weight saving approaches to reduce noise sources, noise transmission paths, and transmitted noise into the passenger. Light weight sound package materials are introduced to treat and reduced airborne noise transmission into multi-material light weight body structure.
2015-06-15
Technical Paper
2015-01-2093
Maxime Henno
A numerical tool has been developed for predicting the unsteady behavior of the thermal wing ice protection systems (WIPS). The code was developed to account for a multi-layer composite structure. The performance predictions of a WIPS integrated into a metallic or into a composite structure can thus be achieved. The tool enables the simulation of unsteady anti-icing operations, for example, the WIPS may be activated with delay after entering into the icing conditions. In this case, ice starts to accrete on the leading edge before the WIPS heats up the skin. Another example is the ground activation of the WIPS for several seconds to check its functionality: low external cooling may cause high thermal constraints that must be estimated with accuracy to avoid adverse effects on the structure. The simulations give further opportunities compared to the current practice.
2015-06-15
Technical Paper
2015-01-2120
Yong Han Yeong, Eric Loth, Jack Sokhey, Alexis Lambourne
Superhydrophobic coatings have shown promise in reducing ice adhesion on a surface. However, recent superhydrophobic ice adhesion studies were conducted at either ice accretion conditions that do not resemble aerospace icing conditions, or at low super-cooled droplet impact speeds (less than 10 m/s). Therefore, a detailed experiment was conducted to measure the ice adhesion strength of various superhydrophobic coatings in an icing wind tunnel at an air speed of 50 m/s and at a temperature of -15°C with a super-cooled icing cloud consisting of 20 µm droplets. The ice was accreted on 3 mm thick, 30 mm diameter discs and then removed by pressurized nitrogen through the access hole in a tensile direction for a measurement of the ice fracture energy. Results showed no relationship between coating wettability parameters (water contact and receding angles) with ice fracture energy but depicted a general increase in fracture energy with increasing surface auto-correlation lengths.
2015-06-15
Technical Paper
2015-01-2160
Alidad Amirfazli
Coatings that shed drops can help with icing mitigation. Shedding of a drop depends on surface wettability. To characterize the shedding of a drop, in an aerodynamic context, the minimum air velocity to displace the drop is measured, i.e., the critical air velocity. Recently, superhydrophobic surfaces (SHS) with their ability to shed drops have gained much attention to combat icing. However, questions remain about their performance when exposed to UV, or water for long periods. In this study of its first kind, the effect prolonged UV and water exposure on shedding of drops from 6 different SHS (four commercially available coatings (C1 to C4), and two developed in-house, S1 and S2) was investigated in an icing wind tunnel. Critical air velocity, and contact angle values show that UV-treatment has a stronger adverse effect for S1 and C1 surfaces, compared to other coatings. Water treatment adversely affects S1, C1 and C2 samples more than other samples.
2015-06-15
Technical Paper
2015-01-2136
Francisco José Redondo
Due to weight constraints, the engine air intake for the Airbus A400M Transport Airplane will be all made in aluminum, and by specification, the intake is protected against ice accretion by a hot air system. In order to assure a fatigue life of the element for the life of the airplane, the temperature of the air supplied must be controlled to a maximum value consistent with aluminum characteristics. A system has been designed wherein hot air is bled and cooled by coolant air from inside the nacelle with a jet pump.While maximum temperature was a constraint for the design of the system, several other constraints appeared during the detailed design of the system; - the tight space allocation inside the nacelle limited the length of the jet pump, - the low temperature provided by the engine bleed in flight idle limited the secondary flow used to cool the engine bleed, and - the complex air distribution needed to supply air to the intake areas. Two variants of the system were developed.
2015-06-15
Technical Paper
2015-01-2204
Michael Funderburg
The ability of various plasticizers to impact the vibration damping properties of polyvinyl chloride (PVC) plastisols was investigated. A material must have good viscoelastic properties in order for it to be an effective vibration damper. However, it is evident that not all viscoelastic materials are good vibration dampers. Consider flexible (plasticized) PVC, for example. PVC formulations demonstrating the same glass transition temperature may have widely different damping capabilities. This presentation will show that the type of plasticizer substantially impacts the damping ability of the final PVC composite. Initially, flexible PVC formulations with varied plasticizers were screened via dynamic mechanical thermal analysis (DMTA) to determine which ones would likely have good damping properties. Formulations which exhibited promising results with DMTA were then tested via an Oberst bar damping test (SAE J1637).
2015-06-15
Technical Paper
2015-01-2344
Murteza T. Erman
In today’s world automotive manufacturers are required to decrease CO2 emissions and increase the fuel economy while assuring driver comfort and safety. To achieve desired acoustic performance targets, automotive manufacturers use various Noise-Vibration-Harshness (NVH) materials which they apply to the vehicle structure either in paint shop or assembly shop. Beside sound deadening coatings applied onto underbody of vehicles they use also either constrained or not-constrained layer of sheets. The majority of these sheets are applied onto floor pan inside the vehicle, known as asphalt-sheets. These asphalt-sheets are highly filled systems with high specific gravity and depending on vehicle 10~20 kg/vehicle application is common. Since early 1990’s, automotive manufacturers also have introduced so called Liquid-Applied Sound Damping materials (LASD).
2015-06-15
Technical Paper
2015-01-2158
Tatsuma Hyugaji, Shigeo Kimura, Haruka Endo, Mitsugu Hasegawa, Hirotaka Sakaue, Katsuaki Morita, Yoichi Yamagishi, Nadine Rehfeld, Benoit Berton, Francesc Diaz, Tarou Tanaka
Recently coatings have been considered as promising preventive measures for in-cloud icing which may occur at the leading edge area of the lifting surface of aircraft in cold climate. In terms of the wettability, coating reveals hydrophobicity or hydrophilicity depending on its property. At the same time it has high or low values on the ice adhesion strength. It is then required that users should find out which of anti-icing or de-icing coating can apply to in order to make full use of the distinguished characteristics. For all that, coating cannot prevent ice accretion by itself unfortunately, which means that no perfect icephobic coatings have been developed up to the present. Thus, coatings apply to the surfaces with devices such as an electric heating system or a load-applying machine such that they can function with less energy and more effectiveness.
2015-06-15
Technical Paper
2015-01-2339
Márcio Calçada, Alan Parrett
Sound absorption materials can be key elements for mass-efficient vehicle noise control. They are utilized at multiple locations in the interior and one of the most important areas is the roof. At this location, the acoustic treatment typically comprises a headliner and an air gap up to body sheet metal. The performance requirement for such a vehicle subsystem is normally a sound absorption curve. Based on headliner geometry and construction, the sound absorption curve shape can be adjusted to increase absorption in certain frequency ranges. In this paper an overall absorption metric is developed to relate design parameters to an absorption curve shape which results in improved in-vehicle performance. This metric is based on sound absorption coefficient and articulation index. Johnson-Champoux-Allard equivalent fluid model and diffuse field equations are used. The results are validated using impedance tube measurements.
2015-06-15
Technical Paper
2015-01-2205
John G. Cherng, Simeng xing, Weiwei Wu, Jan Ladewig, Rolf Balte, Maurice Venegas
A comprehensive and systematic investigation on acoustical performance of carbon nanotube enhanced polyurethane (PU) foams was performed. The complete foam making process was carefully carried out in order to select a stable base foam composition that to be integrated with many carbon nanotube materials. A total of eight design parameters were evaluated, such as loading in weight percentage, diameter of the nanotube, length of the nanotube,coating with Ni, single and multiple layer nanotubes, graphitization of nanotube, radical bonding, and geometry configuration of nanotube, i.e. tube vs. sheet. Both normal incidence sound transmission loss (STL) and absorption coefficient were measured. It was found out that there is an optimum value in most of design parameters. In general, nanotube enhanced PU foam definitely demonstrated improvements in both absorption coefficients and sound transmission loss.
2015-06-15
Technical Paper
2015-01-2159
Philipp Grimmer, Swarupini Ganesan, Michael Haupt, Jakob Barz, Christian Oehr, Thomas Hirth
The formation of ice on surfaces of technical devices or transportation vehicles can lead to several problems, like reduced functionality, reduced energy efficiency or operational safety. As known de-icing methods use a high amount of energy or environmentally harmful chemicals, research has focused lately on passive de-icing by functional surfaces with an improved removal of ice (de-icing) or a reduced formation of it (anti-icing). Inspired by the Lotus plant leaf from nature, a “super-hydrophobic” surface can be produced by the combination of micro-structures and a hydrophobic surface coating. By a hot stamping process we have generated differently shaped microstructures (cylinders, ellipses and lines) on polyurethane films which are afterwards coated by a PECVD process with thin, hydrophobic fluorocarbon or silicone-like films. PU films are suitable for outdoor use, because they are resistant against erosion and UV radiation.
2015-06-15
Technical Paper
2015-01-2207
Pranab Saha, Satyajeet P. Deshpande, Charles Moritz, Steve Sorenson
Standards are essential for evaluating the performance of products properly and for developing a data base for the products. This paper discusses various standards that are available for determining the acoustic performance of sound package materials. The paper emphasizes various SAE standards that are available in this area, the reasons why these standards are important to the researchers working in the mobility industry, the history behind the development of these standards, and how they are different from standards that are available from other standards organization on similar topics.
2015-06-15
Technical Paper
2015-01-2251
ALEX VARGHESE, SATISH PALLED
Background: NVH in Automobile has been very demanding over the years and is considered to be one of the Key focus areas for Customer Satisfaction identified by the Automobile companies. Also the end customer or Automobile users are becoming more conscious about the NVH performance. In today’s world the NVH Department of Automobile companies are mainly focusing on the three Governing factors, a) Performance b) Weight and c) Cost. Also lot of work is been done on finding new ways of testing and evaluating noise levels and predicting the noise path for effective noise treatments. The need of Noise treatment materials along the Noise path becomes very crucial for Noise treatment. Lot of work has been done towards optimizing noise treatment materials and its effective placement to suit performance, weight and cost. The treatment of these noise sources becomes an Engineering art as it involves these combinations of noise sources.
2015-06-15
Technical Paper
2015-01-2342
Jun Zhang, Jian Pang, Siwen Zhang, Xiaoxuan Zhang, Congguang Liu
A Lightweight Dash Insulator Development and Engineering Application for the Vehicle NVH Improvement Jun ZHANG 1,2 , Jian PANG 1,2,*, Cong-guang LIU 1,2, Xiao-xuan ZHANG 1,2, 1 Changan Auto Global R&D Center NVH Department, Chongqing, China, 401120 2. State Key Laboratory of Vehicle NVH and Safety Technology, Chongqing, China,, 401120 * Correspondence author, e-mail address: pangjian@changan.com.cn ABSTRACT The lightweight design for sound package is becoming more and more important in automobile development. The research on lightweight sound package has become one of the hot topics in automobile industry. This paper presents a procedure to develop lightweight dash insulator based on NVH targets. The mechanism to reduce dash panel weight and to improve sound insertion loss simultaneously is described in this paper. The paper illustrates a new lightweight dash insulator structure with surface density 2500g/mm2.
2015-06-15
Technical Paper
2015-01-2202
Catheryn Jackson, Justin E. Gimbal, Dhara Metla
Over the past decade damping materials have made major improvements in contributing to passenger comfort. NVH engineers have further shaped the material specifications to reflect key targeted properties that improve the vehicle design. The specified damping material is then applied to the formed surfaces of the vehicle body to provide optimal performance and achieve the required results. This paper describes how liquid dampers have advanced to meet increased performance requirements through improved loss modulus of the final coating. Data generated by dynamic mechanical analysis shows that this viscoelastic behavior is what drives the performance in damping materials. Through the correlation of loss moduli to damping performance of Oberst bars, the mechanism can be further quantified and explained.
2015-06-15
Technical Paper
2015-01-2209
Sajjad Beigmoradi
Noise, vibration and harshness (NVH) attribute is considered as a crucial passenger comfort aspect by automotive manufacturers. Reducing noise and vibration in each of the three sections (source, path and receiver) finally can result in improvement of passenger comfort. As a matter of fact, engine system is identified as one the most challenging vehicle noise sources. Reduction of radiated engine sound to cabin have significant role in decreasing perceived noise level by occupants. Firewall as the bulkhead part between engine and passenger compartment has dominant role in transferring engine noise to cabin. To prevent this, a perfect design of firewall structure and related insulator specifications are the most challenging problems from automotive NVH point of view. Proper design of firewall insulator requires vast knowledge in respect of material and acoustics.
2015-05-01
Journal Article
2015-01-9081
Sakthinathan Ganapathy Pandian, Srivathsan Puzhuthivakkam Rengarajan, Terrin P Babu, Vignesh Natarajan, Harikrishnan Kanagasabesan
Abstract Functionally Graded Thermal Barrier Coatings (FG-TBC) increases the performance of high temperature components in gasoline engines by decreasing the thermal conductivity and increasing the unburned charge oxidation in the flame quenching area with the increase in temperature near the entrance of the crevice volume between the piston and the liner during the compression and the early part of the expansion strokes. In this study, a 3-D finite element steady state thermal and structural analysis are carried out on both uncoated and functionally graded NiCrAlY/YSZ/Al2O3 coated gasoline engine piston using a commercial code, namely ANSYS. The effects of coating on the thermo mechanical behaviours of the piston are investigated. It has been shown that the maximum surface temperature of the ceramic coated piston is improved approximately by 7% for the Al-Si alloy.
2015-04-14
Journal Article
2015-01-1012
Carl Justin Kamp, Paul Folino, Yujun Wang, Alexander Sappok, Jim Ernstmeyer, Amin Saeid, Rakesh Singh, Bachir Kharraja, Victor W. Wong
Abstract While metal fiber filters have successfully shown a high degree of particle retention functionality for various sizes of diesel engines with a low pressure drop and a relatively high filtration efficiency, little is known about the effects of lubricant-derived ash on the fiber filter systems. Sintered metal fiber filters (SMF-DPF), when used downstream from a diesel engine, effectively trap and oxidize diesel particulate matter via an electrically heated regeneration process where a specific voltage and current are applied to the sintered alloy fibers. In this manner the filter media essentially acts as a resistive heater to generate temperatures high enough to oxidize the carbonaceous particulate matter, which is typically in excess of 600°C.
2015-04-14
Journal Article
2015-01-0893
Michael D. Kass, Chris Janke, Raynella Connatser, Sam Lewis, James Keiser, Timothy Theiss
Abstract The compatibility of plastic materials used in fuel storage and dispensing applications was determined for an off-highway diesel fuel and a blend containing 20% bio-oil (Bio20) derived from a fast pyrolysis process. Bio20 is not to be confused with B20, which is a diesel blend containing 20% biodiesel. The feedstock, processing, and chemistry of biodiesel are markedly different from bio-oil. Plastic materials included those identified for use as seals, coatings, piping and fiberglass resins, but many are also used in vehicle fueling systems. The plastic specimens were exposed to the two fuel types for 16 weeks at 60°C. After measuring the wetted volume and hardness, the specimens were dried for 65 hours at 60°C and then remeasured to determine extent of property change. A solubility analysis was performed to better understand the performance of plastic materials in fuel blends composed of bio-oil and diesel.
2015-04-14
Journal Article
2015-01-0894
Michael D. Kass, Chris Janke, Timothy Theiss, James Baustian, Leslie Wolf, Wolf Koch
Abstract The compatibility of plastic materials used in fuel storage and dispensing applications was determined for a test fuel representing gasoline blended with 10% ethanol. Prior investigations were performed on gasoline fuels containing 25, 50 and 85% ethanol, but the knowledge gap existing from 0 to 25% ethanol precluded accurate compatibility assessment of low level blends, especially for the current E10 fuel (gasoline containing 10% ethanol) used in most filling stations, and the recently accepted E15 fuel blend (gasoline blended with up to15% ethanol). For the majority of the plastic materials evaluated in this study, the wet volume swell (which is the parameter most commonly used to assess compatibility) was higher for fuels containing 25% ethanol, while the volume swell accompanying E10 was much lower.
2015-04-14
Journal Article
2015-01-0888
Michael D. Kass, Chris Janke, Raynella Connatser, Sam Lewis, James Keiser, Timothy Theiss
Abstract The compatibility of elastomer materials used in fuel storage and dispensing applications was determined for an off-highway diesel fuel and a blend containing 20% bio-oil (Bio20) derived from a fast pyrolysis process. (This fuel blend is not to be confused with B20, which is a blend of diesel fuel with 20% biodiesel.) The elastomer types evaluated in this study included fluorocarbon, fluorosilicone, acrylonitrile rubber (NBR), styrene butadiene rubber (SBR), polyurethane, neoprene, and silicone. All of these elastomer types are used in sealing applications, but some, like the nitrile rubbers are also common hose materials. The elastomer specimens were exposed to the two fuel types for 4 weeks at 60°C. After measuring the wetted volume and hardness, the specimens were dried for 65 hours at 60°C and then remeasured. A solubility analysis was performed to better understand the performance of plastic materials in fuel blends composed of bio-oil and diesel.
Viewing 1 to 30 of 14566