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Video

The New Audi A6/A7 Family - Aerodynamic Development of Different Body Types on One Platform

2011-11-17
The presentation describes the aerodynamic development and optimization process of the three different new models of the Audi A6/A7 family. The body types of these three models represent the three classic aerodynamic body types squareback, notchback and fastback. A short introduction of the flow structures of these different body types is given and their effect on the vehicle aerodynamic is described. In order to achieve good aerodynamic performance, the integration into the development process of the knowledge about these flow phenomena and the breakdown of the aerodynamic resistance into its components friction- and pressure drag as well as the induced drag is very important. The presentation illustrates how this is realized within the aerodynamic development process at Audi. It describes how the results of CFD simulations are combined with wind tunnel measurements and how the information about the different flow phenomena were used to achieve an aerodynamic improvement.
Video

Ice Phobic Coatings for Control and Covered Surfaces

2012-03-14
Silicones have been utilized in multiple industries in the last 50 years and their applications are still expanding as technology grows. Ice phobic coatings, as an example, have been utilized on lock walls, navigation channels, wind turbines, hydropower intakes, and aircraft. Without protection these applications have a high risk of failure in the functions they perform. For example, ice build up on an aircraft?s aerodynamic surfaces increases drag which reduces lift during flight operations. Utilizing a silicone ice phobic coating significantly reduces the adhesion of ice to aerodynamic surfaces. Compared to other polymeric materials, silicones are known for their broad operating temperature range and lend themselves to excellent performance in a variety of harsh environments. Especially in low temperatures where ice adhesion is a concern, silicones retain their elastomeric physical properties and low modulus.
Video

Development of Scratch Resistant Clear Coat for Automotive

2012-05-23
Scratch resistance is one of the most important customer requirements for automotive painting. Scratches occur as a result of a load being imposed on a paint film, which then destroys or deforms it. In order to improve the scratch resistance properties of clear coat, a specially developed molecular that act to accelerate closslinking reaction was added to the clear coat main resin. This developed molecular facilitates closslinking between multiple molecules and creates an unprecedentedly fine molecular structure. The result is a soft, highly elastic, and durable clear coat with improved resistance to light and acid as well as enhanced deformation recovery properties. It requires no special maintenance, prevents luster degradation caused by surface scratches and helps to prolong new-car color and gloss. Developmental Clear Coat is introduced into the flagship of the Lexus range - the LS as Self-restoring Coat in 2009. Presenter Junya Ogawa, Developmental Center
Video

Eco+ Solutions in High Performance Plastics from DSM for Automotive.

2012-05-22
DSM will present various application solutions in High Performance Plastics enabling to significant weight or friction reduction and thus to reduced fuel consumption and/or emission levels, and on top of that to lower system costs. Typical Eco+ Solutions Examples to be presented are: - Friction Reduction: Nylon 46 in chain tensioners yielding up to 1 % fuel reduction - Weight Reduction (metal-to-plastic conversion): Nylon 46 with long term temperature resistance upto 230 C in turbo components, Nylon 6 in oil pans/sumps, PET in plastic precision parts, Nylon 46 in gears, many other examples - Electrification: Nylon 46 in start/stop and e-motor components, TPC in HV cables - System Cost optimization: High Flow PA6 in various components, TPC in Brake Tubes - Improved LCA: biobased materials as PA410 and TPC-Eco Typical Application Solutions concern: air induction systems, engine and transmission components, electrical systems, structural&safety parts.
Video

5000 Hours Aging of THERBAN® (HNBR) Elastomers in an Aggressive Biodiesel Blend

2012-05-23
TERBAN® hydrogenated nitrile rubber (HNBR) is a specialty elastomer used in demanding engineering applications such as the automotive, heavy duty, and industrial markets. It has excellent combination of heat, oil and abrasion resistance in addition to its high mechanical strength, very good dynamic and sealing properties. This paper will present data on aging HNBR for five thousand hours in an aggressive and un-stabilized B30A biodiesel fuel blend (70% ULSD, 30% SME, and an aggressive additive package) and explore the effect of HNBR polymer properties and vulcanizate composition on the performance in such fuel blends. Presenter Victor Nasreddine
Technical Paper

Challenges of ‘Green Fuel’ in Filtration System

2009-04-20
2009-01-0872
With increasing use of biodiesel in the world, especially in Europe and the United States, there are challenges to meet the strict industrial standards for water and particulate removal with existing engine filter units while keeping their normal service life. This paper will address the urgency to develop more advanced filter media and technologies for the application. Three typical fuel filters (synthetic, glassfiber, and cellulose) from current market will be investigated and evaluated by dust holding capacity, water removal efficiency, and chemical resistance.
Journal Article

Research on Measurement Method of Road Gradient and Altitude by On-Road Driving

2009-04-20
2009-01-1116
Exhaust emissions from a vehicle under road driving condition is affected by the control state of ECU (Engine Control Unit). This control state highly depends on the driving force of the vehicle. The driving force is nearly equal to the driving resistance, which is the sum of the acceleration resistance, the air resistance, the rolling resistance and the gradient resistance. Although it is essential to take an accurate measurement of the road gradient, it is quite difficult to evaluate the gradient resistance in testing on-road driving. In this study, the measurement methods of the road gradient and the altitude with GPS, gyro sensor and height sensor are reported. The road gradient under the on-road driving condition is evaluated by the combination of measuring the pitch angle with the gyro sensor and measuring the vehicle gradient with the two height sensors. Verifying of this method, the altitude of the driving test route is also evaluated.
Technical Paper

Development of the Texas Drayage Truck Cycle and Its Use to Determine the Effects of Low Rolling Resistance Tires on the NOX Emissions and Fuel Economy

2009-04-20
2009-01-0943
Trucks operating in inter-modal (drayage) operation in and around port and rail terminals, are responsible for a large proportion of the emissions of NOX, which are problematic for the air quality of the Houston and Dallas/Ft. Worth metro areas. A standard test cycle, called the Texas Dray Truck Cycle, was developed to represent the operation of heavy-duty diesel trucks in dray operations. The test cycle reflects the substantial time spent at idle (~45%) and the high intensity of the on-road portions. This test cycle was then used in the SAE J1321 test protocol to evaluate the effect on fuel consumption and NOX emissions of retrofitting dray trucks with light-weight, low-rolling resistance wide-single tires. In on-track testing, a reduction in fuel consumption of 8.7% was seen, and NOX emissions were reduced by 3.8% with the wide single tires compared to the conventional tires.
Technical Paper

Investigation of Aerodynamic Performance due to the Interaction between the Rear Diffuser Angle and the Cooling Airflow Outlet

2010-04-12
2010-01-0290
The purpose of this research is to understand the combined flow of underneath flow and engine-cooling exit flow, as well as the interaction between the rear diffuser angle and the cooling airflow outlet on aerodynamic performance. A 1/8 scale simplified notchback model with an unrestricted internal cooling airflow path was used in this study. And a series of experimental investigations were conducted into aerodynamic performance on different rear diffuser angles in the conditions of closing and opening the cooling airflow path, and on different combinations of the rear diffuser angle and the layout of cooling airflow outlet. The test results show that, after opening the cooling airflow path, the minimum drag can be obtained at a smaller rear diffuser angle; and the lift doesn't continuously decrease with the increase of rear diffuser angle, but decreases first and then increases at an angle.
Technical Paper

Interference between Engine Bay Flow and External Aerodynamics of Road Vehicles

2010-04-12
2010-01-0288
This study focus on the aerodynamic influence of the engine bay packaging, with special emphasis on the density of packaging and its effect on cooling and exterior flow. For the study, numerical and experimental methods where combined to exploit the advantages of each method. The geometry used for the study was a model of Volvo S60 sedan type passenger car, carrying a detailed representation of the cooling package, engine bay and underbody area. In the study it was found that there is an influence on the exterior aerodynamics of the vehicle with respect to the packaging of the engine bay. Furthermore, it is shown that by evacuating a large amount of the cooling air through the wheel houses a reduction in drag can be achieved.
Journal Article

A New Approach to Analyzing Cooling and Interference Drag

2010-04-12
2010-01-0286
This paper presents a new approach to analyzing and developing low-drag cooling systems. A relation is derived which describes cooling drag by a number of contributions. Interference drag clearly can be identified as one of them. Cooling system parameters can be assigned to different terms of the relation, so that differences due to parameter variations of the individual drag contributions can be estimated. In order to predict the interference-drag dependency on the outlet location and the local outlet mass flow, an extensive study on a standard BMW sedan has been carried out, both experimentally and by CFD. The results show the importance of providing consistent outflow conditions which take into account the outlet location and flow direction, in order to minimize cooling drag.
Journal Article

Bolt Load Retention and Creep Response of AS41 Alloyed with 0.15 % Ca

2010-04-12
2010-01-0404
Understanding the creep and bolt load retention (BLR) behavior of promising Mg-Al alloys are crucial to developing elevated temperature resistance alloys. This is especially true for elevated temperature automotive applications with a prevalence of bolted joints. In this study, creep and fastener clamp load response of Mg-Al alloy AS41 was investigated and compared to that of Mg4Al and AS41 micro-alloyed with 0.15 % Ca. A compliance-creep approach was used to model the response of these Mg-Al alloys at bolted joints. The equation prediction of the BLR response and experimental results are in good agreement. AS41+0.15 Ca shows improved creep and BLR properties up to 175°C. A correlation between the microstructures, creep and BLR results reveal that the formation of a ternary CaMgSi phase is responsible for the improved elevated temperature behavior.
Technical Paper

Effect of Road Roughness on the Vehicle Ride Comfort using Semi-Active Suspension System

2010-04-12
2010-01-0384
This paper deals with an investigation of the road roughness on the vehicle ride comfort using semi-active suspension system. A mathematical model of quarter vehicle for semi active suspension system is developed to evaluate vehicle ride comfort. The rolling resistance and power losses are also investigated. The power consumed in rolling resistance and power dissipation in suspension for passive and semi-active suspensions are evaluated. The obtained results showed that ride comfort increases as the road roughness is decreased. Comparisons between passive and semi-active suspensions systems in terms of ride performance and power dissipation are also discussed.
Technical Paper

Reliability and Life Study of Hydraulic Solenoid Valve - Part 2 - Experimental Study

2009-04-20
2009-01-0413
The current work studies the reliability of a solenoid valve (SV) used in automobile transmissions through a joint theoretical and experimental approach. The goal of this work is to use accelerated tests to characterize SV failure and correlate the results to new comprehensive finite element models (Part 1). A custom test apparatus has been designed and built to simultaneously monitor and actuate up to four SVs. The test apparatus is capable of applying a controlled duty cycle, current and actuation frequency. The SVs are also placed in a thermal chamber so that the ambient temperature can be controlled precisely. The apparatus measures in real-time the temperature, current, and voltage of each SV. A series of tests have been conducted to produce repeated failures of the SV. The failure of the SV appears to be caused by overheating and failure of the insulation used in the solenoid coil.
Technical Paper

Surface Modification of EN 8 Steel by Aluminizing and Nitriding for Automotive Applications

2009-04-20
2009-01-0604
The study deals with the surface modification of EN 8 steel by hot dip aluminizing and nitriding, for improving the surface characteristics. The microstructure, microhardness and wear of aluminized, diffused and nitrided (ADN) steel were studied. The studies were conducted based on Taguchi techniques in order to reduce the experimentation efforts. The surface hardness of ADN steel was increased to a maximum of 1200 Hv0.1. X-ray diffraction studies have confirmed the presence of aluminium nitrides in the surface layer which is instrumental for the significant increase in hardness. The wear resistance of ADN steel is high compared to the base metal (BM) and it also has the lowest coefficient of friction. The process parameters were optimized based on the experiments. This could be used for automotive piston rings, where wear is critical.
Technical Paper

Bonding Strength Modeling of Polyurethane to Vulcanized Rubber

2009-04-20
2009-01-0605
Tires manufactured from polyurethane (PU) have been espoused recently for reduced hysteretic loss, but the material provides poor traction or poor wear resistance in the application, requiring inclusion of a traditional vulcanized rubber tread at the contact surface. The tread can be attached by adhesive methods after the PU body is cured, or the PU can be directly cured to reception sites on the rubber chain molecules unoccupied by crosslinked (vulcanizing) sulfur atoms. This paper provides a study of the two bonding options, both as-manufactured and after dynamic loading representative of tire performance in service. Models of each process are introduced, and an experimental comparison of the bonding strength between each method is made. Results are applied to tire fatigue simulation.
Technical Paper

Computational Study of Flow in the Underbody Diffuser for a Simplified Car Model

2010-04-12
2010-01-0119
In this paper, using the facilities offered by the ANSYS CFX, CFD code, the authors investigate numerically the flow around the Ahmed body for the rear slanted upper surface of 35°, fitted with a simple underbody diffuser, without endplates, in order to find the influence of the later one on the main aerodynamic characteristics, drag and lift. Relative motion between body and ground is simulated. The study is performed for different geometrical configurations, length and the angle of the diffuser being the parameters which are varied in ranges which are relevant for hatchback passenger cars. Later, based on a theoretical approach, a coefficient of the equivalent hydraulic resistance of the diffuser is computed, which helps to evaluate the drag due to underbody diffuser.
Technical Paper

Investigation of the Bed and Rear Flap Variation for a Low-Drag Pickup Truck using Design of Experiments

2010-04-12
2010-01-0122
The drag reduction effect was investigated with regard to the bed and rear flap variation for a pickup truck through design of experiments process. The design factors were the bed length, bed height, rear flap length, and flap inset with three levels, and the noise factor was the yaw angle. The signal-to-noise ratio calculation was introduced to evaluate the low-drag performance under a crosswind. Analysis of variance indicated the significant interaction effect between the bed length and bed height. Since the bed flow of the short with low bed was attached to the tailgate, which increased the drag coefficient and lowered the S/N ratio. The rear flap add-on at the rear edge of a roof was effective to reduce the drag coefficient. However, the sensitivity of the flap length variation on the drag reduction was not significant. The flap inset had a negative effect on the drag reduction as it lowered the inset area pressure of the cabin back surface.
Journal Article

Effect of Gaseous Hydrocarbon-Silicon and Load Current on Contact Resistance of Electromagnetic Relays

2010-04-12
2010-01-0204
Automobile engine compartments are exposed to much wider temperature and moisture-level changes than passenger compartments. Therefore, for electrical components housed in the engine compartment, protection of printed circuit boards is extremely important in order to prevent open or short circuits caused by electrochemical reactions. It is well known that silicon oxide accumulates on electromagnetic relay contacts, and may cause degraded circuits once volatile low-mass cyclic polydimetylsiloxane from a commonly used silicone gel waterproofing material reacts in a direct-current arc that occurs when the contacts open and close. Material selection for relay modules is critical in order to avoid this phenomenon. We used a gel material jointly developed with a supplier, and evaluated its reliability compared to silicone in terms of relay operation. This material is a polymer resin that consists of poly(n-butyl acrylate) as the main component, linked through silicon.
Journal Article

The Acoustic Impedance of a Wide Side Branch Orifice: Experimental Determination Using Three-Port Methodology

2009-05-19
2009-01-2043
The acoustic impedance of a circular, confined, side branch orifice subjected to grazing flow is studied. Two geometries are tested. In both geometries, the side branch dimension is of the same order as that of the main duct. The system is viewed as an acoustic three-port, whose passive properties are described by a system matrix. The impedance is studied with the acoustic field incident at different ports, which is shown to influence the results significantly. When excited from the leading edge or from the side branch, an interaction of the hydrodynamic and acoustic fields is triggered, while excitation from the trailing edge does not trigger such an interaction. For both the resistance and the reactance (here expressed as an end correction) the results vary in the three possible excitation cases. In the quasi-stationary limit the resistance is given by a loss coefficient times the Mach number, and the end correction collapses to a single value.
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