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Automotive suppliers provide multi-layer trims mainly made of porous materials. They have a real expertise on the characterization and the modeling of poro-elastic materials. A dozen parameters are used to characterize the acoustical and elastical behavior of such materials. The recent vibro-acoustic simulation tools enable to take into account this type of material but require the Biot parameters as input. Several characterization methods exist and the question of reproducibility and confidence in the parameters arises. A Round Robin test was conducted on three poro-elastic material with four laboratories. Compared to other Round Robin test on the characterization of acoustical and elastical parameters of porous material, this one is more specific since the four laboratories are familiar with automotive applications. Methods and results are compared and discussed in this work.

In order to design vehicles with diminished gCO2/km emissions level, car manufacturers aim at reducing the weight of their vehicles. One of the solutions advocated by the automotive industry consists in the replacement of metallic parts by lighter systems made of polymer reinforced composites. Unfortunately, the numerical simulations set to evaluate the vibratory and acoustic performances of systems made of this kind of materials are often not sufficiently effective and robust so that convincing test/simulation correlations are rarely met. Indeed, for polymer-based materials, numerous parameters affect the vibroacoustic behavior. On the one hand, it is well known that the viscoelastic properties (Storage -Young- and dissipative moduli) of polymers depend on the temperature, loading frequency and sometimes the humidity content.

This paper is a case study from the TESSA project (French funded research program “Transfert des Efforts des Sources Solidiennes Actives”). The general frame of the work was to assess a collaborative design process between a car manufacturer and a major supplier using FE modelling and condensation of structure borne noise sources as an alternative to classic specification method for structure borne sources. Super elements from different FE commercial softwares have been used to assess the reliability of the method, the compatibility of the softwares and, most important, the relevance of applying a blocked force tensor to the component super element to predict the interior contribution of a component which is the originality of this work. The case study is an internal combustion engine cooling module (fan + shroud + exchangers) from VALEO including all assembly details (clips, decoupling elements) modelled under ABAQUS and its integration in a RENAULT Espace under NASTRAN.

For many years, bearing suppliers have been using the specific pressure to evaluate the fatigue risk of conrod bearings. However, modern engines have made the bearing more sensitive to various phenomena such as the thermal expansion or the elasticity of the conrod housing. These effects modify the stresses in the bearing layers and consequently fatigue risk. In this paper, we propose a new way to determine the bearing fatigue resistance. To achieve that, we analyze the elastic and plastic behavior of the bearing along the engine life. We detail and provide the analytical relationships which determine stresses in the overlay and in the substrate of the bearing in order to analyze their fatigue resistance. Various physical loads are taken into account such as the thermal load, the hydrodynamic pressure field, the fitting load, the free spread load. A good knowledge of the relationships between those physical phenomena helps to understand the mechanical behavior of the bearing.

A specific objective of the European Mg-Engine project is to qualify at least two die cast Mg alloys with improved high temperature properties, in addition to satisfactory corrosion resistance, castability and costs. This paper discusses the selection criteria for high temperature alloys leading to four candidate alloys, AJ52A, AJ62A, AE44 and AE35. Tensile-, creep- and fatigue testing of standard die cast test specimens at different temperatures and conditions have led to a very large amount of material property data. Numerous examples are given to underline the potential for these alloys in high temperature automotive applications. The subsequent use of the basic property data in material models for design of automotive components is illustrated.

Eight partners from Europe and one from North America have joined efforts in a EU-supported project to find new ways for sustainable production of Mg-based engine blocks for cars. The ultimate aim of the work is to reduce vehicle weight, thereby reducing fuel consumption and CO2 emissions from operation of the vehicle. Four new magnesium alloys are considered in the project and an engine block has been series cast - 20 each in two alloys. An extensive mechanical testing program has been initiated to identify in particular the high temperature limits of the four alloys and a significant experimental study of proper bolt materials for joining is being done in parallel. Engine redesign and life cycle analysis has also been completed to secure the future sustainable exploitation of the project results. This paper presents an overview of the work and results obtained until now - 3 months before the ending date of the project.

In order to reach OEMs acoustic treatment targets (improving performance while minimizing the weight and cost impact), we have developed an original hybrid approach called “Vehicle Acoustic synthesis method”[1] to simulate - and therefore to optimize - noise treatments for both insulation and absorption, and to calculate the resulting Sound Pressure Level (SPL) at ear points for the middle and high frequency range. To calculate the SPL, we identify equivalent volume velocity sources from intensity measurements, and combine them to acoustic transfer functions (panel/ear) measured or computed with ray tracing codes using the reciprocity principle. Compared to our first approach [1], this paper shows a new measurement technique using pressure-particle velocity probes [2]. This technique allows to reduce acquisition time by a factor four, and makes therefore possible a synthesis method on a complete car within two weeks.

An extensive research program involving the French passenger car and heavy-duty (HD) vehicles manufacturers, sponsored by ADEME and realized by IFP, aimed to characterize in terms of size and composition the particulate emitted by the different engine technologies currently or soon available. The impact of engine settings and fuel composition was also studied. Numerous information was collected in this HD study revealing that fuel composition and particularly non-conventional fuels and engine settings strongly impact the particulate concentration and size distribution. Nucleation is likely to occur when there is less adsorption matter, for instance when post-injection is used or EGR is removed. Particulate composition, particularly PAH and sulfates content, is weakly bound to the size. Mineral elements distribution depends on their origin, lubrication oil or engine wear.

State of the art demonstrates that weight of vehicle increases with length of car body. Integration of powertrain in mid rear underfloor location enables to shorten car body by more than 0,5m and to save partially heavy longitudinal members. Underfloor integration of power train induces higher stance floor for more conviviality of passengers visibility. Safety factors are improved by lowering gravity centre, better repartition of front / rear masses during braking, easier management of crash by straighter and higher front longitudinal members and free front space. Space frame architecture simplifies light weight technologies application by using 2D bended aluminum profiles. Low investment is ensured by minimising castings application to suspension attachments and interlinking upperbody to underbody. Floor and external panels are designed for aluminum sheet stampings.

Progress in Diesel spray modelling highly depends on a better knowledge of the instantaneous injection velocity and of the hydraulic section at the exit of each injection hole. Additionally a better identification of the mechanisms which cause fragmentation is needed. This necessitates to begin with a precise computation of the two-phase flow which arises due to the presence of cavitation within the injectors. For that aim, a VOF type interface tracking method has been developed and improved (Segment Lagrangian VOF method) which allows to describe numerically the onset and development of cavitation within Diesel injectors. Furthermore, experiments have been performed for validation purpose, on transparent one-hole injectors for high pressure injection conditions. Two different entrance geometries (straight and rounded) and various upstream and downstream pressure levels have been considered.

This presented paper deals with NOx trap sulphur poisoning and its regeneration. Sulphur poisoning has been studied with different SO2 gas concentrations under laboratory and engine test bench conditions. The sulphur poisoning studies have shown that the different NOx-traps available in the market have different behaviours toward SO2 poisoning and are all very sensitive to it. The results outline a non linear relationship of the NOx trap sulphur poisoning as a function of SO2 concentration. For instance, engine bench tests show that with a 50 and a 110ppm sulphur containing gasoline, a decrease of 50% in the NOx-trap storage capacity is respectively observed after 20 and 15 hours. With a gasoline containing 20ppm of sulphur, the same deactivation level is observed after 90 hours.

The new generation of drive-by-wire systems currently under development has demanding requirements on the electronic architecture. Functions such as brake-by-wire or steer-by-wire require continued operation even in the presence of component failures. The electronic architecture must therefore provide fault-tolerance and real-time response. This in turn requires the operating system and the communication layer to be predictable, dependable and composable. It is well known that this properties are best supported by a time-triggered approach. A consortium consisting of German and French car manufacturers and suppliers, which aims at becoming a working group within the OSEK/VDX initiative, the OSEKtime consortium, is currently defining a specification for a time-triggered operating system and a fault-tolerant communication layer.1 The operating system and the communication layer are based on applicable interfaces of the OSEK/VDX standard.

This paper deals with fleet management systems and the means to integrate new communication and computer technologies to improve transportation companies efficiency. It focuses on the integration of embedded electronic systems for communication and data management through the use of on-board computers, taking the point of view of the truck manufacturer. It introduces the idea of making the vehicle a nod of a complete communication network. After briefly presenting fleet management problematic and some of the major existing solutions, it analyzes how new technologies can be integrated and what major advantages they would bring.

Laboratory and engine tests were carried out to describe the sulphur effect on the NOx adsorbers catalysts efficiency for gasoline lean burn engines. Two main aspects were studied. The first one deals with the NOx storage efficiency of the adsorber under laboratory conditions, especially regarding the SO2 gas phase concentration. The rate of sulfur storing is greatly affected by the SO2 gas concentration. While 6.5 hours are required to get from 70 % NOx reduction to only 35 % when the gas mixture contains 10 ppm SO2, it takes 20 hours with 5 ppm SO2 and more than 60 hours with the 2 ppm SO2 condition. The relationship between the loss in NOx trap performance and SO2 concentration appears to have an exponential shape. The same amount of sulphur (0.8 % mass) is deposited onto the catalyst within 10 hours with the feed gas containing 10 ppm of SO2 and within 50 hours with 2 ppm SO2. Nevertheless, It was shown that the loss in NOx-Trap efficiency is not the same in these two cases.

The paper presents the VALEO and RENAULT approach to study odor problems for passengers compartment. The first part describes the method chosen to form a panel, and the second part presents a vehicle application.