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Water-cooled charge air cooling is being considered as part of various technology solutions in response to 2007 US, 2010 US, EU4 and EU5 emissions standards. As manufacturers determine appropriate engine and vehicle solutions to meet the upcoming emissions standards, charge air cooling requirements are increasing due to higher turbocharger outlet temperatures and pressures, higher EGR rates, and requests for intake manifold temperature control to manage combustion and exhaust temperatures. Valeo and EMP have collaborated on the development and testing of a water cooled charge air cooler (WCCAC), controlled by a 12 volt brushless motor coolant pump. The system design addresses material temperature limitations of air-air aluminum CAC's and has the potential to simplify the packaging of the air induction system.

Pure tone whine noises produced by transmission gear meshing can be a particular annoyance to vehicle occupants. In this case the gear meshing was exciting a resonance within the transaxle, resulting in an especially obtrusive pure tone noise within a narrow speed range. This report presents the identification of the resonating component and the development of a novel approach to eliminate the noise problem. Specifically a laminated steel (MPM) disk was fastened to the face of the gear to provide damping. Knowledge of the gear's mode of vibration was used to optimize the effectiveness of the damping treatment. This approach is proven to be effective via experimentally verified prototypes

Once a vehicle powertrain is designed and the first prototype is built, extensive on-board instrumentation and testing needs to be carried out at the proving grounds (PG) to generate load histograms for various components. The load histograms can then be used to carry out durability tests in the laboratory. When a component in the vehicle powertrain is changed, the load histograms need to be generated again at the proving grounds. This adds much time and money to the vehicle's development. The objective is to develop a virtual powertrain model that can be simulated through a powertrain endurance driving cycle in order to predict torque histograms and total damage. The predictions are then correlated against measured data acquired on a test vehicle that was driven through the same driving cycle at the proving grounds.

This paper presents a phenomenological single-zone combustion model which meets the particular requirements of high speed DI diesel engines with common rail injection. Therefore the model takes into account the freely selectable pilot and main injection and is strongly focusing on result parameters like combustion noise or NO-emission which are affected by this split injection. The premixed combustion, the mixing-controlled combustion and the ignition delay are key parts of the model. The model was developed and tested on more than 200 samples from three different engine types of DaimlerChrysler passenger car engines equipped with common rail injection. A user-friendly parameterization and a short computing time was achieved thanks to the simple structure of the model.

In order to further reduce NOx emissions in increasing HP EGR cooler performance, several OEMs have decided to use a secondary cooling loop dedicated to bring cold water (around 35°C) to the HP EGR heat exchanger. Nevertheless, strongly cooled EGR gases can condensate in the cooler-producing acidic liquids which can corrode some parts in the loop. It is therefore necessary to define EGR components compatible with such kind of environment and constraints. Testing was performed on a 2.0-liter EU4 diesel engine, using a large panel of current fuels including neat biodiesels from soybean, rapeseed or palm, as well as low and high sulfur petroleum-based diesels. In order to cover all existing cycle conditions, the HP EGR is cooled from 20°C to 90°C independently from the engine coolant circuit.

Testing was performed on a 2.0 liter diesel engine with high pressure (HP) and low pressure (LP) EGR, using standard European low sulfur diesel as well as fatty acid methyl ester (FAME) biodiesel fuels produced from soy, rapeseed and palm feedstock, both neat and blended with 50% standard diesel. In the HP EGR configuration, fuel injection, air flow and EGR rate were adapted to achieve the same engine load and NOx emissions for all fuels at the selected test points. Higher brake specific fuel consumption and lower smoke emissions were observed for the biodiesels compared to the standard diesel. In the LP EGR configuration, large reductions in NOx and smoke were observed for all fuels compared to HP EGR. In addition, water condensed in the charge air cooler at coolant temperatures below 30°C. This condensate was collected and analyzed, finding similar volumes and acidity for condensates from all the diesel and biodiesel fuels.

Two active boom noise damping techniques using a Helmholtz resonator-based compensator and a lead compensator called a positive pressure feedback have been developed at the University of Dayton [1]. The two damping techniques are of feedback type and their compensators can be implemented in software or hardware (using inexpensive operational amplifiers). The active damping system would rely on a speaker, a low-cost microphone, two accelerometers, and an electronic circuit (or a micro-controller) to add damping to the offending low-frequency vibroacoustic modes of the cavity. The simplicity of the active boom noise damping system lends itself to be incorporated into a vehicle's sound system. The Helmholtz resonator-based strategy is implemented on a Dodge Durango sport utility vehicle. The control scheme adds appreciable amount of damping to the first cavity mode and the first structurally induced acoustic mode of the cabin.

Today the worldwide convergence towards stricter fuel consumption and emission regulations is pushing carmakers and suppliers into new fields of innovation. Valeo Engine Cooling, VEC, is contributing towards these goals by applying its thermal management system expertise in order to reduce fuel consumption and emissions by using an advanced engine cooling system that incorporated variable speed PWM fans, an electric water pump and an electric water control valve. The paper discusses the benefits in terms of engine cooling, fuel economy and emissions over the FTP drive cycle. The paper gives some examples of advanced engine cooling strategies based on a virtual, predictive metal temperature sensor that is used to actuate the electrical water pump at the desired flow rate. The electrical balance between the 42V pump and fans has also been optimized to reduce the vehicle electrical power consumption and to keep the coolant temperature close to 110°C.

The main objectives of new technologies for internal-combustion engine are lower consumption, pollutant reduction and comfort passenger increase. To reach these objectives, we have adopted for engine thermal management two strategies: quicker rise temperature during the cold start and higher engine temperature for part load. To satisfy these criteria, we have modified the classic cooling loop. An electric water pump, an electric water valve and variable speed fan system are the new actuators automatically controlled by electronic calculator. This concept allows to obtain a warm-up time reduced by 50% and 2 to 3% fuel economy on the European cycle.

Cutting down fan system development costs, improving quality, and increasing fan efficiency is a challenge that is now being addressed by the engine cooling engineers. In order to attain such a compelling goal, a Virtual Prototyping approach has been adopted, mainly based on Computational Fluid Dynamics (CFD)[7]. For the development of the fans used in the engine cooling systems, CFD now plays a key role as a design tool as well as an optimization tool. Until recently, both complex geometries and low-speed aerodynamics inherent to latter systems have prevented numerical simulations to be part of the design or reblading processes. Since the advent of general purpose CFD softwares capable of adressing the issues pertinent to the engine cooling system fans, a CFD based development of a new standard fan range was initiated. This paper presents the CFD strategy adopted and the results obtained on the new fans.

Deposits on engine parts, and in particular in combustion chambers of modern engines are causing increasing concern in the automobile industry. Highly sophisticated engine management systems make effects on emissions or performance obvious as outgassing of unburned hydrocarbons or variation of spark advance. Reduced mean heat flux away from the cylinder influences engine thermodynamics. Extreme deposits may cause noise increase by carbon rap. A special form of combustion chamber deposits, well known under the synonym spark plug fouling, is a carbon needle on spark plugs, which can cause the total damage of the catalysts (Japanese Industrial Standard D 1606: Adaptability Test Code of Spark Plug for Automobiles) The Co-ordinating European Council for the development of performance tests for transportation fuels, lubricants, and other fluids (CEC) started the development of a new performance test in 1994.

Future emission regulations and customer needs require revolutionary new approaches to engine management systems. In the EC part-funded AENEAS program the partners Ricardo, Kistler and DaimlerChrysler formed a consortium to investigate the application of a new combustion pressure sensor concept and innovative algorithms for engine management systems. This paper describes the general scope and the basic concepts of the system.

Cooled exhaust gas recirculation is emerging as a promising technology to address the increasing demand for fuel economy without compromising performance in turbocharged spark injection engines. There are a number of different possible architectures, each with its specific characteristics. The objectives of this study are to quantify the increase in knock resistance and to decrease the enrichment at full load in order to target stoichiometric operation over the full operating range, and to define a vehicle compatible cooling system to meet the demanding heat rejection requirements. Based on our knowledge in EGR and air loops, the benefits and risks of various cooled EGR turbocharged systems were evaluated and compared in a preliminary phase. Two architectures, one with high pressure EGR and the other with low pressure EGR, were selected and tested on a 2L turbocharged gasoline engine on a stationary test bench and the performance was compared to the serial production engine.

Advanced design of modern engine cooling and vehicle HVAC components involves sophisticated simulation. In particular, front end air flow models must be able to cover the complete range of conditions from idle to high road speeds involving multiple fans of varying types both powered and unpowered. This paper presents a model for electric radiator cooling fans which covers the complete range of powered and unpowered (freewheel) operation. The model applies equally well to mechanical drive fans.

Euro4 and EPA/02 emission regulations for the European and North American Heavy Duty truck market will require development of high efficiency, low pollution diesel engines. Informations received from main engine, truck manufacturers and literature surveys performed during the past two years shows that several technical solutions are being evaluated in order to reach the required emission levels. These technical solutions can be divided into 3 main groups: 1 Further optimization of fuel combustion including: increase of air to fuel ratio, further retardation of fuel injection timing. 2 Cooled EGR including: high recycled exhaust gas ratios, short EGR loop, compressed and aftercooled EGR. 3 Exhaust gas aftertreatment including: de-NOx catalysts, particle traps, particle afterburning. Different technical solutions will have different impacts on the heat rejection requirements and consequently on the layout and costs of the future cooling systems.

More than 200 tensile-shear resistance spot welded specimens were produced and tested to analyze the effect of spot weld spacing, weld size, sheet thickness, and adhesive on the ultimate strength of joints made from a mild hot dip galvannealed steel and an unexposed quality hot dip galvannealed 590 MPa minimum tensile strength dual phase steel (DP590). The geometric layout parameters were analyzed by a design of experiment (DOE) approach. The analysis showed that weld size is a primary factor affecting the strength of the joints for a given material. It was also determined that structural adhesive created a large relative strengthening for joints made from the mild steel. Interactions of the geometrical factors are also presented.

Computer controls are increasingly being employed in systems ranging from simple to very complex. A new trend is to extend these computer systems to include monitoring schemes to detect malfunctions. An example is provided by new automobiles sold in the US, Canada, and Europe. By law they must include “on-board diagnostics” designed to detect certain malfunctions in the powertrain system that may cause excessive emissions. The present article outlines some of the fundamental concepts of system's monitoring and general principles for the design of such monitors.

One of the key elements in efforts to minimize the noise emmissionis of engines and other machinery is the knowledge of the main noise radiating surfaces and the relation between measurable surface vibration and the sound pressure. Under the name of Airborne Source Quantification (ASQ), various techniques have been developed to discretize and quantify the source strength, and noise contributions, of vibrating surface patches of machinery or vehicle components. The noise contributions of patches to the sound pressure at specific locations in the sound field or to the total radiated sound power are identified. The source strength of equivalent point sources, the acoustic transfer from the source surface to critical sound field locations and finally the sound pressure contributions of the individual patches are quantified. These techniques are not unique to engine application, but very relevant for engine development. An example is shown for an engine under artificial excitation.

Vehicle exhaust flow is difficult to measure accurately and with high precision due to the highly transient nature of the cyclic events which are dependent on engine combustion parameters, varying exhaust gas compositions, pulsation effects, temperature and pressure. Bag mini-diluter (BMD) is becoming one of the few technologies chosen for SULEV and PZEV exhaust emission measurement and certification. A central part of the BMD system is an accurate and reliable exhaust flow measurement which is essential for proportional bag fill. A new device has been developed to accurately and reliably calibrate exhaust flow measurement equipments such as the E-Flow. The calibration device uses two different size laminar flow elements (LFE), a 40 CFM (1.13 m3/min) LFE for low end calibration and a 400 CFM (11.32 m3/min) LFE for higher flows. A blower is used to push flow through a main flow path, which then divides into two flow pathways, one for each of the two LFE's.

This paper describes the use of Vibro-Acoustics numerical modeling for prediction of an Air Intake System noise level for a commercial vehicle. The use of numerical methods to predict vehicle interior noise levels as well as sound radiated from components is gaining acceptance in the automotive industry [1]. The products of most industries can benefit from improved acoustic design. On the other hand, sound emission regulation has become more and more rigorous and customers expect quieter products. The aim of this work it is to assess the Vibro-Acoustics behavior of Air Intake System and influence of it in the sound pressure level of the vehicle.