109 resultados para Automotive


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Electroless nickel (EN) coatings are recognised for their hardness and wear resistance in automotive and aerospace industries. In this work, electroless Ni–P coatings were deposited on aluminium alloy substrate LM24 (Al–9 wt.% Si alloy) and the effect of post treatment on the wear resistance was studied. The post treatments included heat treatment and lapping with two different surface textures. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and micro-abrasion tester were used to analyse morphology, structure and abrasive wear resistance of the coatings. Post heat treatment significantly improved the coating density and structure, giving rise to enhanced hardness and wear resistance. Microhardness of electroless Ni–P coatings with thickness of about 15 μm increased due to the formation of Ni3P after heat treatment.

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Turbocompounding is generally regarded as the process of recovering a proportion of the exhaust gas energy from a reciprocating engine and applying it to the output power of the crankshaft. In conventional turbocompounding, the power turbine has been mechanically connected to the crankshaft but now a new method has emerged. Recent advances in high speed electrical machines have enabled the power turbine to be coupled to an electric generator. Decoupling the power turbine from the crankshaft and coupling it to a generator allows the power electronics to control the turbine speed independently in order to optimize the turbine efficiency for different engine operating conditions.

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When simulating the High Pressure Die Casting ‘HPDC’ process, the heat transfer coefficient ‘HTC’ between the casting and the die is critical to accurately predict the quality of the casting. To determine the HTC at the metal–die interface a production die for an automotive engine bearing beam, Die 1, was instrumented with type K thermocouples. A Magmasoft® simulation model was generated with virtual thermocouple points placed in the same location as the production die. The temperature traces from the simulation model were compared to the instrumentation results. Using the default simulation HTC for the metal–die interface, a poor correlation was seen, with the temperature response being much less for the simulation model. Because of this, the HTC at the metal–die interface was modified in order to get a better fit. After many simulation iterations, a good fit was established using a peak HTC of 42,000 W/m2 K, this modified HTC was further validated by a second instrumented production die, proving that the modified HTC gives good correlation to the instrumentation trials. The updated HTC properties for the simulation model will improve the predictive capabilities of the casting simulation software and better predict casting defects.

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Flow maldistribution of the exhaust gas entering a Diesel Particulate Filter (DPF) can cause uneven soot distribution during loading and excessive temperature gradients during the regeneration phase. Minimising the magnitude of this maldistribution is therefore an important consideration in the design of the inlet pipe and diffuser, particularly in situations where packaging constraints dictate bends in the inlet pipe close to the filter, or a sharp diffuser angle. This paper describes the use of Particle Image Velocimetry (PIV) to validate a Computational Fluid Dynamic (CFD) model of the flow within the inlet diffuser of a DPF so that CFD can be used with confidence as a tool to minimise this flow maldistribution. PIV is used to study the flow of gas into a DPF over a range of steady state flow conditions. The distribution of flow approaching the front face of the substrate was of particular interest to this study. Optically clear diffusing cones were designed and placed between pipe and substrate to allow PIV analysis to take place. Stereoscopic PIV was used to eliminate any error produced by the optical aberrations caused by looking through the curved wall of the inlet cone. In parallel to the experiments, numerical analysis was carried out using a CFD program with an incorporated DPF model. Boundary conditions for the CFD simulations were taken from the experimental data, allowing an experimental validation of the numerical results. The CFD model incorporated a DPF model, the cement layers seen in segmented filters and the intumescent matting that is commonly used to pack the filter into a metal casing. The mesh contained approximately 580,000 cells and used the realizable ?-e turbulence model. The CFD simulation predicted both pressure drop across the DPF and the velocity field within the cone and at the DPF face with reasonable accuracy, providing confidence in the use the CFD in future work to design new, more efficient cones.

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A local collaborative process was launched in Windsor, Ontario, Canada to explore the role of occupation as a risk factor for cancer. An initial hypothesis-generating study found an increased risk for breast cancer among women aged 55 years or younger who had ever worked in farming. On the basis of this result, a 2-year case–control study was undertaken to evaluate the lifetime occupational histories of women with breast cancer. The results indicate that women with breast cancer were nearly three times more likely to have worked in agriculture when compared to the controls (OR = 2.80 [95% CI, 1.6–4.8]). The risk for those who worked in agriculture and subsequently worked in automotive-related manufacturing was further elevated (OR = 4.0 [95% CI, 1.7–9.9]). The risk for those employed in agriculture and subsequently employed in health care was also elevated (OR = 2.3 [95% CI, 1.1–4.6]). Farming tended to be among the earlier jobs worked, often during adolescence. While this article has limitations including the small sample size and the lack of information regarding specific exposures, it does provide evidence of a possible association between farming and breast cancer. The findings indicate the need for further study to determine which aspects of farming may be of biological importance and to better understand the significance of timing of exposure in terms of cancer risk.

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The international introduction of electric vehicles (EVs) will see a change in private passenger car usage, operation and management. There are many stakeholders, but currently it appears that the automotive industry is focused on EV manufacture, governments and policy makers have highlighted the potential environmental and job creation opportunities while the electricity sector is preparing for an additional electrical load on the grid system. If the deployment of EVs is to be successful the introduction of international EV standards, universal charging hardware infrastructure, associated universal peripherals and user-friendly software on public and private property is necessary. The focus of this paper is to establish the state-of-the-art in EV charging infrastructure, which includes a review of existing and proposed international standards, best practice and guidelines under consideration or recommendation.

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This article explores two rival understandings of production and what it means to be a rational productive subject. Against ‘technicist’ models of productive reason, it defends a ‘phronetic’ model on both normative and pragmatic grounds. The discussion begins with a description of the general principles underpinning technicist theories of workplace organisation, principles which continue to inform work design approaches to this day. The technicist model is thereafter criticised on three counts: that it represents a specific managerial agenda which privileges sectional interests; that it is suspect morally for a number of reasons; and that despite its aspiration of arriving at ‘one best method’, it represents but one way of organising work processes. The phronetic model is then set out using the notion of ‘practices’ as a guide. This notion is important in providing a view of production in which technical reason is subsumed under a broader practical reason incorporating individual experience and judgement. Against the charge that this view is merely an instance of nostalgic craft romanticism having little relevance to present industrial realities, there are recognisable contemporary instances of phronetic production, one of the most interesting being Volvo’s innovations in automotive assembly systems.

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Turbocompounding is the process of recovering a proportion of an engine’s fuel energy that would otherwise be lost in the exhaust process and adding it to the output power. This was first seen in the 1930s and is carried out by coupling an exhaust gas turbine to the crankshaft of a reciprocating engine. It has since been recognised that coupling the power turbine to an electrical generator instead of the crankshaft has the potential to reduce the fuel consumption further with the added flexibility of being able to decide how this recovered energy is used. The electricity generated can be used in automotive applications to assist the crankshaft using a flywheel motor generator or to power ancillaries that would otherwise have run off the crankshaft. In the case of stationary power plants, it can assist the electrical power output. Decoupling the power turbine from the crankshaft and coupling it to a generator allows the power electronics to control the turbine speed independently in order to optimise the specific fuel consumption for different engine operating conditions. This method of energy recapture is termed ‘turbogenerating’.

This paper gives a brief history of turbocompounding and its thermodynamic merits. It then moves on to give an account of the validation of a turbogenerated engine model. The model is then used to investigate what needs to be done to an engine when a turbogenerator is installed. The engine being modelled is used for stationary power generation and is fuelled by an induced biogas with a small portion of palm oil being injected into the cylinder to initiate combustion by compression ignition. From these investigations, optimum settings were found that result in a 10.90% improvement in overall efficiency. These savings relate to the same engine without a turbogenerator installed operating with fixed fuelling.

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Background

Endocrine disrupting chemicals and carcinogens, some of which may not yet have been classified as such, are present in many occupational environments and could increase breast cancer risk. Prior research has identified associations with breast cancer and work in agricultural and industrial settings. The purpose of this study was to further characterize possible links between breast cancer risk and occupation, particularly in farming and manufacturing, as well as to examine the impacts of early agricultural exposures, and exposure effects that are specific to the endocrine receptor status of tumours.

Methods

1005 breast cancer cases referred by a regional cancer center and 1147 randomly-selected community controls provided detailed data including occupational and reproductive histories. All reported jobs were industry- and occupation-coded for the construction of cumulative exposure metrics representing likely exposure to carcinogens and endocrine disruptors. In a frequency-matched case?control design, exposure effects were estimated using conditional logistic regression.

Results

Across all sectors, women in jobs with potentially high exposures to carcinogens and endocrine disruptors had elevated breast cancer risk (OR = 1.42; 95% CI, 1.18-1.73, for 10 years exposure duration). Specific sectors with elevated risk included: agriculture (OR = 1.36; 95% CI, 1.01-1.82); bars-gambling (OR = 2.28; 95% CI, 0.94-5.53); automotive plastics manufacturing (OR = 2.68; 95% CI, 1.47-4.88), food canning (OR = 2.35; 95% CI, 1.00-5.53), and metalworking (OR = 1.73; 95% CI, 1.02-2.92). Estrogen receptor status of tumors with elevated risk differed by occupational grouping. Premenopausal breast cancer risk was highest for automotive plastics (OR = 4.76; 95% CI, 1.58-14.4) and food canning (OR = 5.70; 95% CI, 1.03-31.5).

Conclusions

These observations support hypotheses linking breast cancer risk and exposures likely to include carcinogens and endocrine disruptors, and demonstrate the value of detailed work histories in environmental and occupational epidemiology.

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The two environmental management system (EMS) standards EMAS and ISO 14001 have been available in Europe for the last 15 years. ISO 14001 has been taken up at a much larger scale but many firms in the German automotive and engineering industry have certified their EMSs according to both standards. Two research questions are addressed: (i) What explains why companies adopt both EMAS and ISO 14001? (ii) Are EMAS and ISO 14001 complements or substitutes? Based on 21 interviews with industrial and institutional representatives, this study finds that, first, the two standards are adopted for completely different reasons: while ISO 14001 is often done as a response to external pressure, EMAS tends to be motivated internally. Second, it is argued that EMAS and ISO 14001 are likely in a situation of direct competition at present which may well turn into complementarity in the future.

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Among the key challenges present in the modelling and optimisation of composite structures against impact is the computational expense involved in setting up accurate simulations of the impact event and then performing the iterations required to optimise the designs. It is of more interest to find good designs given the limitations of the resources and time available rather than the best possible design. In this paper, low cost but sufficiently accurate finite element (FE) models were generated in LS Dyna for several experimentally characterised materials by semi-automating the modelling process and using existing material models. These models were then used by an optimisation algorithm to generate new hybrid offspring, leading to minimum weight and/or cost designs from a selection of isotropic metals, polymers and orthotropic fibre-reinforced laminates that countered a specified impact threat. Experimental validation of the optimal designs thus identified was then successfully carried out using a single stage gas gun. With sufficient computational hardware, the techniques developed in this pilot study can further utilise fine meshes, equations of state and sophisticated material models, so that optimal hybrid systems can be identified from a wide range of materials, designs and threats.

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The adoption of each new level of automotive emissions legislation often requires the introduction of additional emissions reduction techniques or the development of existing emissions control systems. This, in turn, usually requires the implementation of new sensors and hardware which must subsequently be monitored by the on-board fault detection systems. The reliable detection and diagnosis of faults in these systems or sensors, which result in the tailpipe emissions rising above the progressively lower failure thresholds, provides enormous challenges for OBD engineers. This paper gives a review of the field of fault detection and diagnostics as used in the automotive industry. Previous work is discussed and particular emphasis is placed on the various strategies and techniques employed. Methodologies such as state estimation, parity equations and parameter estimation are explained with their application within a physical model diagnostic structure. The utilization of symptoms and residuals in the diagnostic process is also discussed. These traditional physical model based diagnostics are investigated in terms of their limitations. The requirements from the OBD legislation are also addressed. Additionally, novel diagnostic techniques, such as principal component analysis (PCA) are also presented as a potential method of achieving the monitoring requirements of current and future OBD legislation.

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The two-stroke engine, by its nature is very dependent on the unsteady gas dynamics within an exhaust system. This is demonstrated by the tuning effects on two-stroke engines, which have been well documented. In consideration of current emissions legislation, a two-stroke engine can be fitted with a catalytic converter for the outboard, utility or automotive markets. The catalytic substrate represents a major obstruction to the flow of exhaust gas, which hinders the progression of the main exhausted pulse, and in turn effects the scavenging of the cylinder and ultimately the performance of the engine.