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A deeper understanding of the complex phenomenology associated with the multiphase flow-induced noise and vibration in a dynamic valve is of critical importance to the automotive industry. To this purpose, a two-dimensional axisymmetric numerical model has been developed to simulate the complex processes that are responsible for the noise and vibration in a poppet valve. More specifically, an Eulerian multiphase flow model, a dynamic mesh and a user-defined function are utilized to facilitate the modeling of this complicated two-phase fluid-structure interaction problem. For a two-phase flow through the valve, our simulations showed that the deformation and breakup of gas bubbles in the gap between the poppet and the valve seat generates a vibration that arises primarily from the force imbalance between the spring and the two-phase fluid flow induced forces on the poppet.

Advanced high strength steels (AHSS) such as dual phase (DP) steels are now being extensively used to achieve light weighting goals of vehicles because of their attractive combination of formability and high strength. High strength low alloy (HSLA) steels are also used in lightweight bodies-in-white; DP and HSLA steels are therefore often laser butt-welded together into tailor welded blanks and to create other joints. Among the laser welding processes, fiber laser welding (FLW) has been shown to provide excellent quality welds, including superior weld mechanical properties, at higher speeds than those possible with other laser welding processes. Using dissimilarly welded DP980-HSLA blanks made with different welding parameters, the tensile properties were found to not change in spite of the HSLA being weaker than the soft zone on the DP980 side of the weld.

This paper presents the implementation of an off-line optimized torque vectoring controller on an electric-drive vehicle with four in-wheel motors for driver assistance and handling performance enhancement. The controller takes vehicle longitudinal, lateral, and yaw acceleration signals as feedback using the concept of state-derivative feedback control. The objective of the controller is to optimally control the vehicle motion according to the driver commands. Reference signals are first calculated using a driver command interpreter to accurately interpret what the driver intends for the vehicle motion. The controller then adjusts the braking/throttle outputs based on discrepancy between the vehicle response and the interpreter command.

Recent work at the University of Waterloo addressed the hot stamping of a lab-scale B-pillar using a heated and cooled die to produce a tailored part with a soft and hard region for which the microstructure was predominantly bainitic and martensitic, respectively. This paper addresses the tensile properties of the transition zone (hard to soft region) within this tailored hot stamping using experimental and numerical methods. Vickers hardness measurement showed that the fully softened and hardened material conditions were achieved across a 25 mm transition zone. Sub-size ASTM uniaxial tensile specimens were cut from the transition zone and pulled to failure. Due to the large variation in material properties within the gauge length of the specimens, apparent uniform elongations measured across the gauge length ranged from 0.02 to 0.04 engineering strain, while the calculated engineering ultimate tensile strength (UTS) varied from 798 to 913 MPa.

In this work, a new air hybrid engine configuration is introduced in which cam-based valvetrain along with three-way and unidirectional valves make the implementation of different air hybrid engine operational modes possible. This configuration simplifies the air hybrid engine valvetrain significantly and relaxes the necessity of using fully flexible valvetrain in air hybrid engines. Utilizing the proposed configuration allows compression braking (CB), air motor (AM), startup and conventional modes of operation to be realized. The proposed configuration is modeled in GT-Power and the deceleration of a typical vehicle, utilizing only regenerative braking system, is simulated. The efficiency of the system in storing the vehicle's kinetic energy is determined using second law definition for efficiency. The stored energy can be used to either start up the engine or run the off-engine accessories. These two modes are studied and compared.

PEM fuel cell is a promising alternative green power source for vehicular application. However, its performance, cost and durability are sensitively impacted by its sensitivity to impurities in both fuel and air streams. In this study, a multi-phase multi-dimensional model with carbon monoxide in the anode side has been developed. The present model includes flow channel, gas diffusion layer, catalyst layer, and polymer electrolyte membrane, considering carbon monoxide (CO) poisoning and oxygen bleeding in the fuel stream. The model equations, based on the conservation laws for mass, momentum, energy, and species, considered in a steady state, are solved by using Fluent software. The results of the effects of CO concentration, a series of 3D simulation in anode catalyst layer, as well as oxygen bleeding, are presented, which indicate that CO has a severe influence on the performance of PEM fuel cell.

The effects of the physical and chemical properties of biodiesel fuels on the combustion process and pollutants formation in Direct Injection (DI) engine are investigated numerically by using multi-dimensional CFD models. In the current study, methyl butanoate (MB) and n-heptane are used as the surrogates for the biodiesel fuel and the conventional diesel fuel. Detailed kinetic chemical mechanisms for MB and n-heptane are implemented to simulate the combustion process. It is shown that the differences in the chemical properties between the biodiesel fuel and the diesel fuel affect the whole combustion process more significantly than the differences in the physical properties. While the variations of both the chemical and the physical properties between the biodiesel and diesel fuel influence the soot formation at the equivalent level, the variations in the chemical properties play a crucial role in the NO emissions formation.

Interest in magnesium, as the lightest engineering metal, has increased in the automotive industry as a result of requirements for lighter and cleaner vehicles. Resistance spot welding (RSW) is already the predominant mode of fabrication in this industry, and the fatigue of spot welded magnesium sheet must be studied. In this study, the tensile and fatigue strength of resistance spot welded AZ31 Mg alloy was studied. Three sets of tensile shear spot welded specimens were prepared with different welding parameters to achieve different nugget sizes. Metallographic examination revealed grain size changes from the base material (BM) to heat affected zone (HAZ) to the fusion zone (FZ). Monotonic tensile and fatigue tests were conducted and the effect of nugget size on tensile shear and fatigue strength was discussed.

Magnesium alloys are the lightest structural metal and recently attention has been focused on using them for structural automotive components. Fatigue and durability studies are essential in the design of these load-bearing components. In 2006, a large multinational research effort, Magnesium Front End Research & Development (MFERD), was launched involving researchers from Canada, China and the US. The MFERD project is intended to investigate the applicability of Mg alloys as lightweight materials for automotive body structures. The participating institutions in fatigue and durability studies were the University of Waterloo and Ryerson University from Canada, Institute of Metal Research (IMR) from China, and Mississippi State University, Westmorland, General Motors Corporation, Ford Motor Company and Chrysler Group LLC from the United States.