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For the 2003 model year DaimlerChrysler Corporation will launch a totally new 5.7L V-8 engine for applications of the Dodge Ram pick-up truck. The new engine was created largely within a digital environment using the latest computer aided design (CAD) and computer aided engineering (CAE) techniques and tools. Utilizing a co-located team of design engineers, designers, and CAE engineers enabled the simulations to impact the design from program inception to the assembly line, saving program time and investment. This paper describes the successful merging of design and advanced analysis techniques by highlighting examples throughout the new HEMI® program. Case studies include issues in the areas of structural optimization, engine loading, lubrication circuit, cooling circuit, and manufacturing.

Improvements to 1D engine modeling accuracy and computational speed have led to greater reliance on this simulation technology during the engine development process. The benefits of modeling show up in many ways: increased simulation iterations for better optimization, reduction in prototype hardware iterations, reduction in program timing and overall cost. In this study a 1D GT-Power model of a turbocharged engine system was used to assist in the initial design phase and throughout the program. The model was developed using Chrysler Group LLC proprietary modeling features for predictive combustion and knock event prediction. In all stages of this project the model's accuracy was improved through regular correlation with dynamometer data. This paper mainly focuses on engine compression ratio selection, turbocharger selection, and cycle-to-cycle variation/cylinder-to-cylinder variation reduction through the combination of 1D GT-Power model optimization and dynamometer tests.

This paper presents a process for the selection of spring rate and pre-load for an adaptively controlled pivoting vane oil pump. The pivoting vane pump has two modes: high and low speed. A spring within the pump is installed to induce a torque that causes an adaptive displacement mechanism within the pump to move toward maximum oil chamber size. In low speed mode, two feedback regions are pressurized that produce torques that counter the spring generated torque. Together, both regions being pressurized by main oil gallery pressure tend to reduce pump displacement more at lower speeds than if only a single chamber is pressurized. At higher speeds, a solenoid switch turns off pressure to one of the feedback pressure chambers, thereby reducing feedback torque that counters spring torque. This enables higher pressure calibrations in this speed mode. In this paper, we identify a process for choosing the spring rate and pre-load that calibrates the adaptive displacement mechanism.

Interference assessments of a stepped-radius power-train component moving within a deformed stepped bore often arise during engine and transmission development activities. For example, when loads are applied to an engine block, the block distorts. This distortion may cause a cam or crankshaft to bind or wear prematurely in its journals as the part rotates within them. Within an automatic transmission valve body, care must be taken to ensure valve body distortion under oil pressure, assembly, and thermal load does not cause spool valves to stick as they translate within the valve body. In both examples, the mechanical scenario to be assessed involves a uniform or stepped radius cylindrical part maintaining a designated clearance through a correspondingly shaped but distorted bore. These distortions can occur in cross-sections (“out-of-round”) or along the bore (in an “s” or “banana” shaped distortions).

The benefits of utilizing virtual engineering include not only shortened product development time and reduced reliance on expensive physical testing, but also the opportunities for greater standardization to support higher product quality. This paper describes a project for building a smart meshing template with a CAD/CAE link. The objective of the project is to optimize the utilization of CAD software and CAE preprocessing software capabilities. The deliverable of the project is a cylinder head mesh template which meets all the cylinder head durability simulation meshing requirements, and which links to CAD/CAE software. Special surface areas identified are built into the cylinder head CAD model design. By using one of the features in CAD software, all the special surfaces can be automatically updated throughout the design process.

Computer applications have been widely used to assist product design. The successes and sophistication of computer aided engineering (CAE) techniques are respectfully recognized in this field. CAE applications in the manufacturing area however are still developing, although the manufacturing community is increasingly starting to pay attentions to computer simulations in its daily workings. This paper will briefly introduce some of these applications and promote awareness of computer simulations in manufacturing area. It contains four main sections: finite element analysis (FEA) in machining fixture design, FEA applications in component assembly, machining process simulations and machining vibrations in the milling operation. Each section comes with a practical case study, potential benefits are identified and conclusions are presented by using an integrated design and analysis approach.

Valvetrain dynamics modeling and engine combustion modeling are often carried out independently. As a result, the interaction between these two physical responses may not be accurately assessed. The objective of this work is to understand the impact that robust valve timing simulations, implemented using a fully coupled valve train dynamics and engine performance model, have on engine performance prediction. The integrated simulation and detailed technical approach are discussed through the presentation of an example implementation. An I4 engine model is developed in which engine performance and valvetrain dynamics modeling are coupled. A benefit of this multi-physics approach is that it reduces reliance on empirically derived estimates of valve lash in favor of physical modeling of engine valvetrain dynamics that predicts lash during engine performance modeling.

The mathematical models that predict friction losses for an internal combustion (IC) engine are described in this paper. These models are based on a combination of fundamental physics and empirical results. These include predictions of losses arising from friction and viscous fluid motion associated with the relative movement of solid surfaces within a piston assembly, the cranktrain, and valvetrain components. The engine friction losses are defined in the context of the geometries of the particular components within an IC engine. Details of these formulations are given, including novel geometry-related coefficients. Different regimes of lubricated friction are considered. In order to establish the model fidelity and robust solution methodology, the mathematical models are validated against engine friction tests. Utilization of these models enables practical solutions to the development of new low friction IC engines that leads to improved engine mechanical efficiency and fuel economy.