Search Results

The use of simulation tools by vehicle manufacturers to design, optimize and validate their vehicles is essential if they are to respond to the demands of their customers, to meet legislative requirements and deliver new vehicles ever more quickly. The use of such tools in the aerodynamics community is already widespread, but they remain some way from replacing physical testing completely. Further advances in simulation capabilities depend on the availability of high quality validation data so that simulation code developers can ensure that they are capturing the physics of the problems in all the important areas of the flow-field. This paper reports on an experimental program to generate such high quality validation data for a SAE 20 degree backlight angle notchback reference model.

One of the most critical challenges currently facing the diesel engine industry is how to improve fuel economy under emission regulations. Improvement in fuel economy can be achieved by precisely controlling Air/Fuel ratio and by monitoring fuel consumption in real time. Accurate and repeatable measurements of fuel rate play a critical role in successfully controlling air/fuel ratio and in monitoring fuel consumption. Volumetric and gravimetric measurements are well-known methods for measuring fuel consumption of internal combustion engines. However, these methods are not suitable for obtaining fuel flow rate data used in real-time control/measurement. In this paper, neural networks are used to solve the problem concerning discontinuous data of fuel flow rate measured by using an AVL 733 s fuel meter. The continuous parts of discontinuous fuel flow rate are used to train and validate a neural network, which can then be used to predict the discontinuous parts of the fuel flow rate.

Anticipating the need to improve the level of comfort for passengers in future aircraft designs, a study on the cost of providing more space for economy class seating has been conducted. Using an existing aircraft design (B777) as the baseline and British Airways published accounts it was shown that only about three extra economy ticket sales would be necessary to offset the operating cost increase associated with the larger fuselage. Franchising and carriage of cargo in the extra space was also investigated but shown to be uneconomic. The effect of aircraft size was studied by applying the analysis to a larger (MD12) and smaller (B757) aircraft. These investigations showed that provision of extra space is more advantageous for the larger aircraft but still remains economic for the smaller type. The method provides the basis for more detailed analysis in future studies.

The promise of thermo-electric (TE) technology in vehicles is a low maintenance solid state device for power generation. The Thermo-Electric Generator (TEG) will be located in the exhaust system and will make use of an energy flow between the warmer exhaust gas and the external environment. The potential to make use of an otherwise wasted flow of energy means that the overall system efficiency can be improved substantially. One of the barriers to a successful application of the technology is the device efficiency. The TE properties of even the most advanced materials are still not sufficient for a practical, cost effective device. However the rate of development is such that practical devices are likely to be available within the next fifteen years. In a previous paper [ 1 ], the potential for such a device was shown through an integrated vehicle simulation and TEG model.

Flexible Printed Circuits (FPCs) have been used extensively in instrument clusters and more recently in headliners of some vehicles. Interest in large area FPCs as a replacement for traditional wiring harnesses has been propelled by the potential benefits, which include weight and space savings, ease of assembly into the vehicle, intelligence through direct mounting of electronic components, and creative design opportunities. This paper describes the development of a specification for flexible copper-clad dielectric materials to be used in the construction of a large FPC intended to replace an instrument panel wiring harness.

Extensive research has been performed for on-board hydrogen generation, such as pyrolysis of metal hydrides (e.g., LiH, MgH₂), hydrogen storages in adsorption materials (e.g., carbon nanotubes and graphites), compressed hydrogen tanks and the hydrolysis of chemical hydrides. Among these methods, the hydrolysis of NaBH₄ has attracted great attention due to the high stability of its alkaline solution and the relatively high energy density, with further advantages such as moderate temperature range (from -5°C to 100°C) requirement, non-flammable, no side reactions or other volatile products, high purity H₂ output. The H₂ energy density contained by the system is fully depend on the solubility of the complicated solution contains reactant, product and the solution stabilizer. In this work, an approach based on thermodynamic equilibrium was proposed to model the relationship between the solubility of an electrolyte and temperature, and the effect of another component on its solubility.

Coastdown testing is a proven method for determining the drag coefficients for road cars whilst the vehicle is in its normal operating environment. An accurate method of achieving this has been successfully developed at Loughborough University. This paper describes the adaptation and application of these techniques to the special case of a contemporary Formula One racing car. The work was undertaken in conjunction with the Benetton Formula One racing team. The paper outlines the development and application of a suitable mathematical model for this particular type of vehicle. The model includes the aerodynamic, tyre, drivetrain and the un-driven wheel drags and accounts for the change in aerodynamic drag due to ambient wind and changes in vehicle ride height during the coastdown. The test and analysis methods are described.

The use of thermo-electric (TE) generation systems in internal combustion engines (ICEs) to reduce the carbon dioxide emission by harnessing the exhaust thermal energy is showing increasing promise. In addition, integration with after treatment devices is a development route for this technology that offers a great potential. Recent work on TE systems have shown that the overall efficiency of present TE generation systems are constrained by, the limitations of the conversion efficiency and operating temperatures of TE materials; fabrication quality, durability and thermal performance of the thermo-electric modules (TEMs); geometrical configuration and heat exchange efficiency of thermo-electric generator (TEG) and; conversion techniques of the TEG's electrical output to a form suitable for vehicle systems.

The established method of clearing a misted car windshield or of maintaining a clear view under misting conditions is through the application of an air supply via jet outlets in the instrument panel. The ability of such arrangements to perform adequately is a function of the prevailing environmental conditions, the vehicle speed, the condition of the demist air source and the geometry and arrangement of the jet outlets. This paper presents experimental data obtained in a purpose built environmental chamber designed to accommodate simple rectangular jets impinging on a misted glass surface. The facility consists of three conditioned air sources applied to a test chamber designed to represent the external, internal and demist air flows. Mist conditions on the glass surface are determined using a novel technique employing a CCD camera acquiring grey scale images which are digitally analysed to generate mist detection, grading and clearing contour data.

An experiment is described in which students from two universities, one in the UK and one in the USA, worked together in multidisciplinary teams on aircraft design projects to satisfy the “capstone” design course requirements in their respective degree programs. Aeronautical, Mechanical, Industrial, and Systems Engineering students from Virginia Tech and Loughborough University were placed on teams to work on two different airplane designs. The paper describes the evolution of this educational collaboration and the organization of the experiment. It also reviews the program ’s successes and its problems. Recommendations are made for continuation of the program and to guide others who might be interested in pursuing a similar experiment.

Modelling of turbochargers based on steady state operating maps for turbine and compressor rotors is widely recognized to have limitations arising from flow pulsations and heat transfer effects that are not well accounted for by interpolation and extrapolation from the mapped data. With implementation of low pressure exhaust gas recirculation systems and multi-stage boosting, the inlet conditions of centrifugal compressors vary more widely than traditional single stage compression systems. Understanding the impact of the inlet conditions on irreversibilities, and therefore efficiency complements existing works on pulse flow and heat transfer effects in informing the engine modelling community. This research experimentally explores the effect of inlet pressure and temperature on the total-total efficiency of a steady flow centrifugal compressor across a range of conditions in isolation of pulse flow effects and with negligible heat transfer.

This paper presents the implementation of a vehicle and powertrain model of the parallel hybrid electric vehicle which can be used for several purposes: as a model for estimating fuel consumption, as a model for estimating performance, and as a control model for the hybrid powertrain optimisation. The model is specified as a multi-domain physical model in MATLAB Simscape, which captures the key electrical, mechanical and thermal energy flows in the vehicles. By applying hand crafted boundary conditions, this model can be simulated either in the forwards or backwards direction, and it can easily be simplified as required to address specific control problems. Modelling in the forwards direction, the driver inputs are specified, and the vehicle response is the model output. In the backwards direction, the vehicle velocity as a function of time is the specified input, and the engine torque, and fuel consumption are the model outputs.

Panel Discussions held at the SAE World Congress in both 2013 and 2014 observed that a shortage of good quality engineering talent formed a chronic and major challenge. (“Good quality” refers to applicants that would be shortlisted for interview.) While doubts have been expressed in some quarters, the shortage is confirmed by automotive sector employers and the Panel's view was that it was symptomatic of a range of issues, all of which have some bearing on the future of the profession. Initiatives to improve recruitment and retention have had varying degrees of success. Efforts need to be intensified in primary schools where negative perceptions develop and deepen. Schemes like AWIM that operate on a large scale and are designed to supplement school curricula should operate at an international level. Universities represent the entry point into the engineering profession and their role in the recruitment process as well as education and training is crucial.

There has probably never been such a demand for professionally qualified engineers, and yet both the number and diversity of people entering the profession continue to decline. Worldwide, there are very many initiatives - some generally encouraging interest in the profession, and others targeting specific audiences. The reports speak of local success, but the overall picture remains discouraging. In this paper we focus on the “pipeline” from primary education through to the transition from graduate engineer into an experienced member of engineering staff. We have based the discussion on both the presentations and comments made during a panel discussion held at the 2013 SAE International Congress. The paper is intended as a summary of the points raised during that discussion and, we hope proves to be starting point for further investigation and analysis. Of particular note is the sheer diversity of initiatives, and the pressing need for role models and mentoring.