Published Article / Since 1995 South Africa's automotive industry has had to adjust to market liberalisation, rapidly integrate into global supply chains, adapt to World Class levels of competitiveness, and has seen increased ownership by multinationals. The effects of these changes on R&D activities are examined here. Data from the national R&D survey are used to further explore the structure and direction of automotive R&D. It is found that R&D activity is under pressure, and likely to decline. However, there are certain niche areas in which R&D is more resilient and likely to continue.

No description available.

Automotive catalytic converters are increasingly used to reduce emissions from internal combustion engines to comply with emission regulations. Maldistributed flow across the catalyst affects its warm up, light off time, ageing, and conversion efficiency. This thesis concerns flow distribution in automotive catalytic converters and methods to improve CFD predictions. Previous studies showed that modelling the monolith flow resistance using the Hagen- Poiseuille’s formulation under predicted flow maldistribution. The predictions were improved by incorporating an additional pressure loss term V2 2 1  , where V is transverse velocity just upstream of a monolith channel, for oblique entry of the flow into the monolith known as the entrance effect. Further improvement was obtained by incorporating the critical angle of attack method. However, there was no experimental evidence to support these oblique entry loss formulations. There also remained the possibility that under prediction of flow maldistribution might be due to the failure to predict flow in the diffuser accurately. A one-dimensional oblique angle flow rig was designed and built to measure the effect of oblique entry flow losses in monoliths. Experiments were performed at different angles of attack (α), using different lengths of substrate and a methodology was developed to obtain the oblique flow entrance losses. The results showed that the pressure loss attributed to the entrance effect increased with the angle of attack. The entrance effect was also found to be dependent on channel Reynolds number and substrate length. The theoretical assumption of V2 2 1  predicts accurately at low Reynolds number but looses its validity at high Reynolds number. From the experimental studies, an improved correlation for the entrance effect has been derived as a function of major controlling variables, i.e., angle of attack, length of the substrates and Reynolds number. A two-dimensional rig was designed to measure the flow field using PIV in a 2-D diffuser placed upstream of two different length substrates. The results showed that the flow in a wide angle diffuser consisted of a central core, free shear layer and recirculation regions. The near-field region was found similar to that of a plane jet. The flow field was found to be independent of Reynolds number. Increasing the substrate length resulted in a flattening of the axial profiles close to the substrate face. A CFD study was undertaken to predict maldistributed flow at the exit of the substrate for an axisymmetric catalyst model by incorporating the measured entrance effect correlation. A fixed critical angle of attack (αc,F) approach was used whereby the entrance effect is assumed constant for α>αc,F. Incorporating the entrance effect with αc,F= 810 improved the prediction of maldistribution in the flow profiles. A 2-D CFD study was undertaken to predict the flow distribution in the diffuser and downstream of the substrate. A comparison of the CFD predictions in the diffuser using different turbulence models showed that all the turbulence models used in this study over predicted the width of the central core region and the V2F turbulence model gave velocity predictions that compared best with PIV. Incorporating the entrance effect improved the predictions close to the diffuser-substrate interface and downstream of the substrate.

<p> This thesis focuses on the static optimization of a fuel cell plug-in hybrid electric vehicle. The vehicle is been powered by three (3) sources of electrical energy. These sources of electrical energy are: fuel cell, supercapacitor, and lithium-ion battery. </p><p> The main target of this thesis is to make good the performance of a fuel cell plug-in hybrid electric vehicle. This will be achieved by applying static optimization method on the dynamic equations of a moving hybrid vehicle. </p><p> The optimization model of this plug-in hybrid electric vehicle (PHEV) was formulated bases on multiple objectives. The objective parameters are: cost, volume, and mass. We were able to apply static optimization algorithm to find optimal solutions for both the objective values and decision variables of the multiple energy sources. </p><p> The optimization model formulated from the dynamic equations, objective specifications, and design constrains were found to be feasible, bounded, and optimizable by subjecting the primal optimization model to its equivalent dual optimization test. </p><p> Advanced vehicle simulator (ADVISOR) was used to stimulate vehicle performance of our design on a standard driving cycle. The results provide a better outcome than that of standard driving cycles.</p><p>

<p> This research presents cyber-physical systems (CPS) modeling of the smart charging process to both identify and analyze potential vulnerabilities that may exist during the interaction and integration between an Electric Vehicle (EV) and the Electric Vehicle Service Equipment (EVSE). As EVSEs are increasingly being integrated into building energy management systems and interfaced with electric vehicles, safe and secure integration of these systems is of paramount importance for the safety and security of the nation's critical infrastructure and people. Both the charging station and electric vehicles have electro-mechanical components built from 3rd party providers, and there is no mechanism to check for safe and secure integration of EVs and EVSEs. The overall goal of the proposed research is to apply formal methods to verify and validate the cyber-physical interactions between the EV and EVSE to gain insight into vulnerable system states and their impacts. To that end, each component (EV and EVSE) was considered its own cyber-physical system and then separately broken down into individual states of operation. The states of each system were compared to determine how the EV and EVSE interacted on a fundamental level, with one system's state becoming the catalyst for change within the other system. These individual models were completed and subsequently integrated using the open-source software Ptolemy II. Upon successfully completing the interactions, the model was scrutinized using linear temporal logic (LTL) operators to test its veracity and projectability. The initial EV/EVSE model was then altered to emphasize previously determined vulnerabilities within the integrated system in order to verify their existence and potential for harming the system. Two such vulnerabilities were demonstrated in this research to confirm integrity of the model, which will be a valuable asset going forward to ensure the future safety of both operators and consumers regarding EV and EVSE interaction.</p><p>

As the cost of wireless devices approaches zero, it becomes more feasible to replace wires with wireless communication. Vehicle wiring harnesses are traditionally wired to communicate both power and information simultaneously, resulting in separate circuits for each vehicle device. X-By-Wireless seeks to supplant this configuration in favor of a shared power bus and wireless inter-component communication. In doing so, we can recognize a number of benefits such as reduced weight and increased reliability, flexibility, and upgradeability. However, this introduces new problems such as longer transmission delays, interference and encryption issues, fusing difficulties, and public perception regarding safety. The purpose of this thesis is to define the X-By-Wireless concept and to investigate the benefits and drawbacks in implementing X-By-Wireless. Furthermore, we do a theoretical and case study analysis to expand upon the weight reduction benefit so as to quantify the expected improvements. We also address each of the challenges presented by X-By-Wireless and integrate them into a proposed circuit that is capable of performing all the necessary functions of wireless control, wireless sensing, and fusing. We find that the proposed device can be mass-produced as an effective solution that meets the speed and security constraints necessary for most vehicle components.

The topic of this thesis is the generation of electricity from hydrocarbon fuels via polymer electrolyte fuel cells (PEFC). The aim has been to develop methods and hardware for experimental evaluation of process parameters and design variables in PEFC reformate cells and stacks. Reformate fuel cell systems have the potential to offer a way for utilizing fuels efficiently with low global and local emissions. Reforming of hydrocarbon fuels may also provide a way around the famous “chicken or egg” dilemma of hydrogen vehicles and infrastructure. In this thesis current distribution measurements are introduced as a tool for investigating the current distribution in a PEFC with Pt/C or PtRu/C anode catalyst as function of reformate fuel gas composition. It is shown that CO may induce a strong transient behavior, with respect to current density, on both Pt/C and PtRu/C catalysts, depending on mode of operation. Analysis of the exhaust fuel gas showed that the oxygen in the air bleed most likely reacts close to the anode inlet, but this is not visible in the measured current density plots.  The time dependence of the CO poisoning reactions is studied more closely in a commercial fuel cell stack. The development of a test fuel cell system, called multisinglecell, that can multiply the capacity of a conventional test station is reported. The setup is successfully demonstrated with initial screening of the corrosion resistance of different stainless steel grades and coatings. Most of the iron originating from a stainless steel sample accumulates in the MEA and GDLs. These results were validated with a similar measurement in a commercial fuel cell stack. The experimental validation of a 3D FEM computer endplate model, which can accurately predict pressure distribution within any type of fuel cell at any temperature, is described. The model could reliably predict trends in changes in the compression pressure distribution. The PBI fuel cell competes with the PEFC in small-scale power applications. A high temperature break-in procedure for PBI fuel cells is developed, which can rapidly and reproducibly ensure stable cell behavior. / QC 20101130

There is a strong desire among automobile manufacturers to reduce the fuel consumption and greenhouse gas emissions of their current vehicles. Reducing the overall weight of a vehicle represents the most practical opportunity to reduce fuel consumption. Replacing the current steel sheet structures with lightweight alternatives, such as aluminum, offers an excellent solution. Much of the attention in North America has been focused on copper-containing Al-Mg-Si aluminum alloys (6xxx series), such as AA6111. These alloys offer an excellent combination of good formability and precipitation-strengthening ability.<p> In this study, the effect of solute concentration on the strength and strain aging behavior of a proprietary Al-Mg-Si-(Cu) alloy was evaluated. The experimental design used was a 26 full factorial design, with the primary factors being the solute concentrations of magnesium, silicon, and copper, as well as the effects of applied strain (cold work), and natural and artificial aging heat treatments (e.g., a simulated paint bake process). The primary investigative techniques employed included tensile testing, microhardness measurements, and optical metallography.<p> The results show that cold work and artificial aging produce the most substantial strengthening in the alloys. The occurrence of natural aging prior to forming and artificial aging reduced strengthening. The highest strength levels in the naturally aged and paint baked condition, which most closely resembles what is found in industry, were achieved at a combination of low magnesium levels (i.e., 0.5 wt.%) and high silicon and copper levels (i.e., 0.9 and 0.3 wt.%, respectively).

There is a strong desire among automobile manufacturers to reduce the fuel consumption and greenhouse gas emissions of their current vehicles. Reducing the overall weight of a vehicle represents the most practical opportunity to reduce fuel consumption. Replacing the current steel sheet structures with lightweight alternatives, such as aluminum, offers an excellent solution. Much of the attention in North America has been focused on copper-containing Al-Mg-Si aluminum alloys (6xxx series), such as AA6111. These alloys offer an excellent combination of good formability and precipitation-strengthening ability.<p> In this study, the effect of solute concentration on the strength and strain aging behavior of a proprietary Al-Mg-Si-(Cu) alloy was evaluated. The experimental design used was a 26 full factorial design, with the primary factors being the solute concentrations of magnesium, silicon, and copper, as well as the effects of applied strain (cold work), and natural and artificial aging heat treatments (e.g., a simulated paint bake process). The primary investigative techniques employed included tensile testing, microhardness measurements, and optical metallography.<p> The results show that cold work and artificial aging produce the most substantial strengthening in the alloys. The occurrence of natural aging prior to forming and artificial aging reduced strengthening. The highest strength levels in the naturally aged and paint baked condition, which most closely resembles what is found in industry, were achieved at a combination of low magnesium levels (i.e., 0.5 wt.%) and high silicon and copper levels (i.e., 0.9 and 0.3 wt.%, respectively).

The goal of this work is to investigate the physical mechanisms that distress thrust washer bearings through physical modeling and numerical techniques. The thrust washer bearing is subjected to non-axisymmetric loads within the planetary gear sets of automatic transmissions in automobiles. In practice the thrust washer bearing often distresses severely and unpredictably, causing transmission breakdown and liability issues. A specially designed thrust washer bearing test rig allows for controlled variation of the operational parameters (speed, load, lubrication flow rate, etc.) governing the tribological behavior of the washer. The test rig also records pertinent real-time data (frictional torque and temperature) from the bearing. In conjunction with the experimental model, a new comprehensive numerical simulation of thrust washer bearings is constructed. The numerical simulation incorporates the effects of macro-scale deformation, micro-scale surface asperity contact, heat generation, boundary and full film lubrication. To model surface asperity contact, the current work performs an extensive finite element study of elasto-plastic spherical contact. The numerical and experimental results show that significant sliding asperity contact can cause high temperatures, high friction, and severe wear.