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With increasingly stringent emissions regulations and concurrent requirements for enhanced engine thermal efficiency, a comprehensive characterization of the automotive gasoline fuel spray has become essential. The acquisition of accurate and repeatable spray data is even more critical when a combustion strategy such as gasoline direct injection is to be utilized. Without industry-wide standardization of testing procedures, large variablilities have been experienced in attempts to verify the claimed spray performance values for the Sauter mean diameter, Dv90, tip penetration and cone angle of many types of fuel sprays. A new SAE Recommended Practice document, J2715, has been developed by the SAE Gasoline Fuel Injection Standards Committee (GFISC) and is now available for the measurement and characterization of the fuel sprays from both gasoline direct injection and port fuel injection injectors.

There are benefits of using ultra thin wall (UTW) substrates (i.e., 900/2, 400/4, etc) in lowering cost and emission level. However, the more fragile mechanical characteristics of the UTW present a challenge to design and manufacture of robust catalytic converters. This paper describes a method of canning trial, where a combined Design of Experiment / Monte-Carlo analysis method was used, to develop and validate a canning method for ultra thin wall substrates. Canning trials were conducted in two stages-- Prototype Canning Trial and Production Canning Trial. In Prototype Canning Trial, the root cause of substrate failure was identified and a model for predicting substrate failure was established. Key factors affecting scrap rate and gap capability were identified and predictions were performed on scrap rate and gap capability with the allowed variations in the key factors. The results provided guidelines in designing production line and process control.

This paper describes two electronic throttle controllers of Visteon Corporation with one already in production and the other currently under development. Analysis and tuning of the two controllers are described. The general structure of the controllers consists of a reference shaping subsystem and a proportional-plus-integral-plus-derivative(PID) controller supplemented with additional terms that deal with the nonlinearility of the electronic throttle body. Due to a friction cancellation term in the controller that minimizes the nonlinearity of the system, linear system analysis techniques are applied. The transfer functions of the electronic throttle body at six different operating conditions are derived. Analysis of the closed-loop dynamics is performed based on the plant and the controller transfer-functions. Controller fine-tuning is performed using frequency response techniques, MATLAB simulations and testing on the actual system.

Automotive gear oil development has expanded beyond the historical requirements of emphasizing wear protection to encompass modern needs for fuel economy and limited slip frictional properties. This paper describes the development process of a new generation, fuel efficient gear lubricant for use in light duty vehicles. A systematic formulation approach was used, encompassing fluid viscometrics and additive optimization. Performance testing in both laboratory and vehicle tests is described. Though standard GL-5 tests were used to confirm oxidation, wear and corrosion performance, emphasis is given to those methods used for optimizing fuel economy.

Visteon has developed a CAE procedure to qualify instrument panel (IP) products under the vehicle key life test environments, by employing a set of CAE simulation and durability techniques. The virtual key life test method simulates the same structural configuration and the proving ground road loads as in the physical test. A representative dynamic road load profile model is constructed based on the vehicle proving ground field data. The dynamic stress simulation is realized by employing the finite element transient analysis. The durability evaluation is based on the dynamic stress results and the material fatigue properties of each component. The procedure has helped the IP engineering team to identify and correct potential durability problems at earlier design stage without a prototype. It has shown that the CAE virtual key life test procedure provides a way to speed up IP product development, to minimize prototypes and costs.

The purpose of this study is to develop specifically a correlation between Exhaust Manifold Cracking Laboratory Test results and 150,000 mile customer fleet usage test results. The study shows that the exhaust manifold design meets the reliability requirements of 10 years or 150,000 miles, given 90th percentile customer usage without an evidence of cracking or audible leaks. This correlation between the Lab Test and the customer Fleet results has been expressed as an acceleration factor. An acceleration factor is the ratio of how much quicker the engine dynamometer test ( i.e. Lab Test ) can accumulate the effect of customer usage over time versus the customers themselves. The acceleration factor is provided for useful life time period of 10 years or 150,000 miles. The recommended acceleration factor, determined in this study, is 38 to 1, comparing the engine dynamometer test ( i.e. Lab Test ) results to 150,000 mile modular truck customer fleet field results.

Realizing the value of knowledge, corporations are turning to Knowledge Based Engineering (KBE) as a design process. A fuel rail KBE tool was created at Visteon with the purpose of increasing knowledge retention and delivering knowledge based designs to the customer much quicker than with conventional methods. Currently, both engineers and CAD designers are using the Fuel Rail KBE Modeler at Visteon. It has been used on many vehicle programs and has saved the company countless person-hours of development time. The Fuel Rail KBE Modeler is a powerful tool that saves resources through automation of both the design and analysis processes. This paper documents the incorporation of automated FEA capability into the KBE environment.

Based on our error budget analysis, the urea SCR aftertreatment system is uncontrollable under EPA 2007-emission level without an effective closed-loop control strategy. The objective of the closed-loop control is to improve transient response as well as reduce the steady state control error. But the inherent large dead time in the urea SCR aftertreatment system makes the closed-loop control a challenge. In this paper, an innovative closed-loop control architecture is introduced, which combines model-based feedforward control with variable gain-scheduling feedback control. Transient response is improved with the inverse-dynamic feedforward control and the variable-gain closed-loop control. The steady-state response is improved with the closed-loop control. Based on this new strategy, a controller is designed and validated under the simulation and test cell environment. Comparison with the baseline open-loop controller is also conducted. Finally, some conclusions are presented.

The purpose of this paper is to present a common sense practical method for establishing and demonstrating reliability objectives. In particular, this paper will: describe an operational definition of “useful life”, describe an accelerated laboratory test procedure for demonstrating that products meet the useful life objective, and describe a method for demonstrating correlation between customer usage and laboratory testing.

Occupant knee impact simulations are performed in the automotive industry as an integrated design process during the course of instrument panel (IP) development. All major automakers have different categories of dynamic testing methods as part of their design process in validating their designs against the FMVSS 208 requirement. This has given rise to a corresponding number of knee impact simulations performed at various stages of product development. This paper investigates the advantages and disadvantages of various types of these knee impact simulations. Only the knee load requirement portion of the FMVSS208 is considered in this paper.

Computational Fluid Dynamics (CFD) is an integral part of product development at Visteon Climate Systems with a validated set of CFD tools for airflow and thermal management processes. As we increasingly build CAE capabilities to design not only thermal comfort, but quiet systems, developing noise prediction capabilities becomes a high priority. Two Broadband Noise Source (BNS) models will be presented, namely Proudman's model for quadrupole source and Curle's boundary layer model for dipole source. Both models are derived from Lighthill's acoustic analogy which is based on the Navier-Stokes equations. BNS models provide aeroacoustic tools that are effective in screening air handling systems with higher noise levels and identifying components or surfaces that generate most of the noise, hence providing opportunities for early design changes. In this paper, BNS models were used as aeroacoustic design tools to redesign an automotive HVAC center duct with high levels of NVH.

Electronics components are estimated to be between 9 to 15 % of a total vehicle cost, and this trend will remain strong for the next years. The amount of electronics content in a vehicle has grown steadily since 1970's, and as a result, development challenges such as testing and validation are a key aspect of its overall development costs. Testing costs can amount easily to US$ 500 k in medium complex automotive parts of a vehicle (e.g. instrument cluster) depending on a specific OEM customer demand, and this on top of limited regional laboratory capacity can also lead to increased testing time. The goal of this paper is to outline key aspects of electronics in vehicle components testing, including overall costs and timing, and propose a lean approach to optimize such costs & timing. The key aspects of such optimization include not only resources, but also laboratories and upfront OEM customer planning.

Occupant head impact simulations on automotive instrument panels (IP) are routinely performed as part of an integrated design process during the course of IP development. Based on the requirements (F/CMVSS, ECE), head impact zones on the IP are first established, which are then used to determine the various “hit” locations to be tested/analyzed. Once critical impact locations are identified, CAE simulations performed which is a repetitive process that involves computing impact angles, positioning the rigid head form with an assigned initial velocity and defining suitable contacts within the finite element model. A commercially available CAE process automation tool was used to automate these steps and generate a head impact simulation model. Once the input model is checked for errors by the automated process, it can be submitted to a solver without any user intervention for analysis and report generation.

An effort to integrate a structural optimization process into the carbon canister bracket design is presented to demonstrate the benefits of an upfront Computer-Aided Engineering (CAE) driven design. Structural optimization methods - including topology, shape, and size optimization - are used to develop the injection molded plastic carbon canister bracket. Furthermore, the incorporation of the Knowledge Base Engineering (KBE) features in the design process not only accelerates the design process but also ease manufacturing feasibility. Even though topology optimization has been widely used to explore the initial topological designs of different products, it is still a great challenge to explore shell like structure designs with 3D solid design package spaces using topology optimization method.

Tuned mass dampers are frequently used in vehicles to resolve vibration issues arising from problematic torsional modes. The design of a tuned damper is straightforward, but evaluating its effect on other system modes is time consuming. An upfront design tool will accelerate the process of designing and evaluating the damper's affect on system level dynamic characteristics. Computer aided engineering tools have been developed to design a tuned torsional damper using two different approaches. In the first approach, a two-degree of freedom torsional system model is utilized. In the second approach, a detailed finite element model of a driveline system is considered. In the second approach, the effect of the damper to the vehicle driveline system response at the hypoid pinion nose and other desired locations is studied to assess the effectiveness of the damper design. In both approaches, the damper rotational inertia is considered as a design variable.

A test load specification is required to validate an automotive product to meet the durability and design life requirements. Traditionally in the automotive industry, load specifications for design validation tests are directly given by OEMs, which are generally developed from an envelop of generic customer usage profiles and are, in most cases, over-specified. In recent years, however, there are many occasions that a proposed load specification for a particular product is requested. The particular test load specification for a particular product is generated based on the measured load data at its mounting location on the given type of vehicles, which contains more realistic time domain load levels and associated frequency contents. The measured time domain load is then processed to frequency domain test load data by using the fast Fourier transform and damage equivalent techniques.

The stand alone oil to air (OTA) transmission cooling strategy with thermostatic cold flow bypass valve has been shown to be an effective means of improving the warmup of an automatic transmission. Improving the system warmup rate of an automatic transmission significantly improves its efficiency by reducing losses resulting from extremely viscous transmission fluid and can allow for calibration changes that improve overall transmission performance. Improved transmission efficiency in turn allows for improved engine efficiency and performance. The improvements obtained from increased transmission and engine efficiency result in an overall increase in vehicle fuel economy. Fuel economy and consumption are important parameters considered by the vehicle manufacturer and the customer. Fuel economy can be considered as important as reliability and durability.