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The 1-D model of a radial centripetal turbine was developed for engine simulation to generalize and extrapolate the results of experiments to high pressure ratio or off-design velocity ratio using calibrated tuning coefficients. The model concerns a compressible dissipative flow in a rotating channel. It considers both bladed or vaneless turbine stators and a twin-entry stator for exhaust pulse manifolds. The experiments were used to find values of all model parameters (outlet flow angles, all loss coefficients including an impeller incidence loss) by an original method using repeated regression analysis. The model is suitable for the prediction of a turbocharger turbine operation and its optimization in 1-D simulation codes.

In recent years, improvements in the fuel economy and exhaust emission performance of internal combustion engines have been increasingly required by regulatory agencies. One of the salient concerns regarding general purpose engines is the larger amount of CO emissions with which they are associated, compared with CO emissions from automobile engines. To reduce CO and other exhaust emissions while maintaining high fuel efficiency, the optimization of total engine system, including various design parameters, is essential. In the engine system optimization process, cycle simulation using 0-D and 1-D engine models are highly useful. To define an optimum design, the model used for the cycle simulation must be capable of predicting the effects of various parameters on the engine performance. In this study, a model for predicting the performance of a general purpose SI (Spark Ignited) engine is developed based on the commercially available engine simulation software, GT-POWER.

In many countries of the world, carburetor motorcycles are the major transportation system for people. The large volumes of these motorcycles contribute to high levels of urban emissions and this fact promotes the relevant emissions regulations to become more stringent. This paper presents an approach to satisfy various new emissions regulations such as Euro-III and Taiwan 4th generation emissions regulations by optimizing the 4-stroke PFI (Port Fuel Injection) engine management system (EMS) and after-treatment system.

An efficient design of the gearbox is crucial for the expected performance of the vehicle both in terms of life and NVH. This involves design and analysis of gears, shafts, bearings, gear layout and speed ratios. Conventionally gears, shafts and bearings are designed and analysed independently. When the design of these parts change, their effect on related parts is estimated separately, leading to loss of time. Alternately, an integrated approach through simulation is adopted for the new two wheeler's gearbox by modeling on Romax designer software, consisting of shafts, bearings and gears. For the target load cycle, gear and bearing lives, shaft deflections and stresses are estimated. While the targets for stresses, deflections and lives are set logically and with experience, these are also compared with those of reference vehicle by creating and analysing reference gearbox model.

This paper summarizes the techniques and guidelines which were used to reduce the driver perceived noise level of a 145-210 HP series of agricultural tractors. Graphs of case study test results and comments on subjective noise quality are provided to guide the acoustic novice through the complexities of the vehicle sound environment in a methodical problem solving format.

Transfer path analysis is a powerful tool to support the vehicle NVH development. On the one hand it is a fast method to gain an overview of the complex interplay in the vehicle noise generation process. On the other hand it can be used to identify critical noise paths and vehicle components responsible for specific noise phenomena. FEV has developed several tools, which are adapted to the considered noise phenomena: Powertrain induced interior noise and vibration is analyzed by VINS (Vehicle Interior Noise Simulation), which allows the deduction of improvement measures fast enough for application in the accelerated vehicle development process. Further on vehicle/powertrain combinations not realized in hardware can be evaluated by virtual installation of the powertrain in the vehicle, which is especially interesting in the context of engine downsizing from four to three or six to four cylinders.

In a running engine, various impacts are excitation sources for structural vibrations and engine noises. Engine noises are classified, depending on their excitation sources, into the combustion noise, the combustion induced mechanical noise and the mechanical noise. It is difficult to measure such noises separately because some impacts occur closely in time and space. In this paper, a transient noise generation model of an engine was proposed considering vibration and its damping of engine structure. The present model was verified through the single explosion excitation experiment for a stationary engine. Using the noise generation model, the combustion noise was separated from the total noise radiating from a running four-stroke gasoline engine for motorcycles. It was found that the combustion noise had larger power at lower frequencies than higher frequencies. However, its contribution to the total engine noise was relatively small.

This paper presents a summary of body structural analysis applied to the 1989 Suzuki Sidekick/Geo Tracker at various stages of development and design. The structure analysis techniques were applied previously to rigidity, vibration, strength, crashworthiness and optimization. The studies confirm that the CAE technique for body structure analysis is more beneficial if it is utilized in the earlier structure development stages particularly for vibration and crashworthiness. Through the extensive use of the structural analysis technique in conjunction with the experiment, the design concept of the Sidekick/Tracker body has been optimized to a most extent.

A student team from Minnesota State University, Mankato's Automotive Engineering Technology program entered the Clean Snowmobile Challenge 2000. A 1998 Polaris Indy Trail was converted to indirect fuel injection running on a computer controlled closed loop fuel system. Also chassis, exhaust, and hood design modifications were made. The snowmobile was designed to compete in eight events. These events included acceleration, emissions, hill climb, cold start, noise, fuel economy/range, handling/driveability, and static display. The snowmobile modifications involved every aspect of the snowmobile with special emphasis on emissions and noise. Laboratory testing led to the final design. This paper details the modifications and test results.

Without engine noise, the cabin of an electric vehicle is quiet, but on the other hand, it becomes easy to perceive refrigerant-induced noise in the automotive air-conditioning (A/C) system. When determining the A/C system at the design stage, it is crucial to verify whether refrigerant-induced noise occurs in the system or not before the real A/C systems are made. If refrigerant-induced noise almost never occurs during the design stage, it is difficult to evaluate by vehicle testing at the development stage. This paper presents a 1D modeling methodology for the assessment of refrigerant-induced noise such as self-excitation noise generated by pressure pulsation through the thermal expansion valve (TXV). The GT-SUITE commercial code was used to develop a refrigerant cycle model consisting of a compressor, condenser, evaporator, TXV and the connecting pipe network.

This paper presents 1D engine simulation used for engine control strategy optimization for a twin-scroll turbocharged gasoline direct injection 2.0 L engine with twin camphaser. The results show good agreement of the engine model behavior with testbed acquisitions for a large amount of steady state set points and under transient operating conditions. The presented method demonstrates that a 1D engine code represents a useful and efficient tool during all steps of the engine control development process from design to real-time for such an advanced engine technology.

Handling performance of a vehicle is a key characteristic determining the response of vehicle under different operating scenarios. An insight into these vehicle-handling characteristics at early stage can be extremely useful in the design and development process. Tire characterization and tuning is important and mandatory to scrutinize each functional and individual parameter of tire. Tire force and moment data is having a significant effect in vehicle handling. Segregation of tire parameter, which is contributing vehicle-handling performance, helps to identify and perform optimization for improvisation. The main objective of this study is development and integration optimized 1D tire model into multibody dynamics model of the vehicle to observe various vehicle compliances towards its handling performance target.

Two vehicle level test methods were developed that illustrate the relationship between 1st order noise in a cabin, and driveline imbalance contributors. At the launch of a new 2005 4WD sport utility vehicle program, a significant boom noise complaint was observed on many vehicles between 55-70 mph. The full time, electronic actively controlled, torque biasing transfercase was intensely reviewed as a potential source of excessive torque induced imbalance. Testing of the transfercase was performed on imbalance measurement stands, dynamometers, and in the vehicle. The result was the identification of two issues. First was that two internal to the transfercase parts were found to have excessive runout. Second was that there was a lack of vehicle correlation to transfercase imbalance. An extensive effort involving over 50 vehicles of the same model was pursued to find the source of the problem.

The demands for comfort and a cleaner environment have been increasing for the past years for motorcycle as well as car manufacturers. With the need to decrease the time-to-market, there is a clear drive to apply CAE-based methods in order to evaluate new designs and to propose design changes that solve any identified problems. More specifically, the demands on the comfort of the rider are not only related to ride & handling and vibration levels(1), but also to the noise levels generated by the motorcycle. This paper presents the virtual modeling of one-cylinder engine of a motorcycle that identifies the mechanism behind the generation of an annoying noise. Furthermore, different possible design changes were evaluated in order to solve the problem. A combined experimental and numerical approach was followed to achieve this. Experiments were used to identify important parameters that determine the engine behavior and thus are critical for the modeling of such an engine.

This paper documents a joint development process between General Motors and Dow Automotive to improve primary body structure frequencies on the GM family of midsize vans by utilizing cavity-filling structural foam. Optimum foam locations, foam quantity, and foam density within the body structure were determined by employing both math-based modeling and vehicle hardware testing techniques. Finite element analysis (FEA) simulations of the Body-In-White (BIW) and “trimmed body” were used to predict the global body structure modes and associated resonant frequencies with and without structural foam. The objective of the FEA activity was to quantify frequency improvements to the primary body structure modes of matchboxing, bending, and torsion when using structural foam. Comprehensive hardware testing on the vehicle was also executed to validate the frequency improvements observed in the FEA results.

The General Motors (GM) Corvette design team was challenged with providing a C6 Z06 vehicle spaceframe that maintained the structural performance of its C5 predecessor while reducing mass by at least 56 kg. An additional requirement inherent to the project was that the design must be integrated into the C6 assembly processes with minimal disruption, i.e. seamless integration. In response to this challenge, a collaborative team was formed, consisting of design engineers from General Motors, Alcoa and Dana Corporation. The result of this collaborative effort is an aluminum Z06 spaceframe that satisfies the high performance expectations of the vehicle while reducing the mass by approximately 62 kg. The frame consists of aluminum extrusions, castings and sheets joined by MIG welding, laser welding and self-piercing rivets. The extrusions are 6XXX series alloys, the castings are permanent mold A356 while the sheet panels are formed from the 5XXX series of alloys.

General Motor's Corvette product engineering was given the challenge to find mass reduction opportunities on the painted body panels of the C6 Z06 through the utilization of carbon fiber reinforced composites (CFRC). The successful implementation of a carbon fiber hood on the 2004 C5 Commemorative Edition Z06 Corvette was the springboard for Corvette Team's appetite for a more extensive application of CFRC on the C6 Z06 model. Fenders were identified as the best application for the technology given their location on the front of the vehicle and the amount of mass saved. The C6 Z06 CFRC fenders provide 6kg reduction of vehicle mass as compared to the smaller RRIM fenders used on the Coupe and Convertible models.

The 2013 SRT Viper Carbon Fiber X-Brace, styled by Chrysler's Product Design Office (PDO), is as much of a work of art as it is an engineered structural component. Presented in this paper is the design evolution, development and performance refinement of the composite X-Brace (shown in Figure 1). The single-piece, all Carbon Fiber Reinforced Plastic (CFRP) X-Brace, an important structural component of the body system, was developed from lightweight carbon fiber material to maximize weight reduction and meet performance targets. The development process was driven extensively by virtual engineering, which applied CAE analysis and results to drive the design and improve the design efficiency. Topology optimization and section optimization were used to generate the initial design's shape, form and profile, while respecting the package requirements of the engine compartment.

To provide optimal performance of a small DI diesel in relation to noise, emissions and fuel economy, an experimental investigation was carried out using Taguchi methods. A single cylinder 3.5 kW diesel was selected for performance test at different engine speeds, loads and static injection timings. These controlled parameters were varied at three levels and the resulting changes in response variables viz. engine noise, smoke, HC, NOx, CO, CO2 emissions and fuel economy (b.s.f.c) were observed. The levels for low noise, smoke, emissions and b.s.f.c could be predicted and relevant combination of controlled parameters specified. Confirmation engine runs were carried out and the results showed good agreement with the predicted optimized quantities of interest based on Taguchi analysis. The effect of engine parameters to the above responses was evaluated in terms of percent contributions by using analysis of variance.