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The mixture formation process in a stratified-charge spark-ignition engine under moderate load conditions has been determined from fuel concentration measurements obtained from planar laser-induced fluorescence (PLIF) of a fluorescence fuel marker, 3-pentanone. A one-cylinder 4-valve engine, specifically designed to provided optical access through the walls of the combustion chamber and through a piston window, was used. In order to gain insight into the processes influencing the fuel motion and mixing, average fuel concentrations were recorded in four different planes between 0.7 mm to 15 mm below the spark plug for various crank-angle positions during the inlet and compression stroke and for two different injection timings. These measurements give a mean 3-dimensional picture of the time history of the fuel distribution.

Experiencing the results of virtual NVH analysis in an immersive physical simulation is the only accurate method of developing vehicle, system or component targets and designs. This paper describes an engineering approach specifically created to enable physical interaction with test, CAE and hybrid NVH models, at every stage in the vehicle design process from concept to full detail. It explains the need for sound and vibration decomposition and synthesis, and interactive sound and vibration replay. Implementation of this process has led to the development of engineering tools that enable Interactive NVH Simulation. The paper also describes the practical use an engineer can make of a ‘rapid prototyping’ desktop NVH simulator in the design process. A full scale NVH Simulator is then used to allow evaluation of final design alternatives under realistic driving conditions by non-specialists (i.e. the customer) as well as specialists.

The influence of a large truck on the aerodynamics of a small passenger car in an overtaking manoeuvre on the motorway was considered, many years ago, during the 1970's, to be a potential problem for the vehicle aerodynamicist. The concern never became significant as vehicle architecture evolved and car weights increased. The current drive for improved fuel economy is advocating that a considerable reduction in vehicle mass is desirable and therefore it may be time to readdress the significance of the truck passing manoeuvre. A quasi-steady experiment has been undertaken at small model scale to examine the aerodynamic characteristics of a small car in proximity to a large truck. Measurements at yaw were included to crudely simulate the effects of a crosswind. The wind tunnel data is presented and the limitations of the experimental procedure are discussed.

Results from a series of experimental measurements are presented in order to investigate the influence of the ground-plane boundary layer on the overall characteristics of a scale model road vehicle. The wind tunnel model is a generic bluff body which has a streamlined forebody, simple wheel representation and interchangeable rear end sections. The aerodynamic forces and moments were measured via an external 3-component balance at a free stream velocity of 24 m/s. corresponding to Reynolds number of 5.5 × 105 based on model length, over a range of ride heights and yaw angles. The ground plane boundary layer thickness was varied artificially. The influence of wheels and underbody roughness were also investigated.

Today, we are all strongly dependent on the correct functioning of technical systems. They fail, and we become vulnerable. Disruptions due to degradation or anomalous behavior can negatively impact safety, operations, and brand name, reducing the profitability of all elements of the value chain. This can be tolerated if the link between cause and effect is understood and remedied. Anomalous behavior, which indicates systems or subsystems not acting in accordance with design intent, is a much more serious problem. It includes unwanted system responses and faults whose root cause can’t be properly diagnosed, leading to costly, and sometimes unnecessary, component replacements. The title No Fault Found: The Search for the Root Cause was developed to propose solutions to this technical and business challenge, which has become less and less acceptable to the commercial aviation industry globally.

A new control strategy for wheel slip control, considering the complete dynamics of the electro-hydraulic brake (EHB) system, is developed and experimentally validated in Cranfield University's HiL system. The control system is based on closed loop shaping Youla-parameterization method. The plant model is linearized about the nominal operating point, a Youla parameter is defined for all stabilizing feedback controller and control performance is achieved by employing closed loop shaping technique. The stability and performance of the controller are investigated in frequency and time domain, and verified by experiments using real EHB smart actuator fitted into the HiL system with driver in the loop.

Millimetre wave radar sensors are being actively developed for automotive applications including Intelligent Cruise Control (ICC), Collision Warning (CW), and Collision Avoidance (CA). Knowledge of the road geometry is of fundamental importance to these future intelligent automotive systems. The interest in such systems is evidenced by manufacturers now starting to incorporate radars in production luxury vehicles. Determination of the road geometry, day and night, under all weather conditions, is a challenging problem requiring both fundamental research and systems studies. Current automotive radar systems rely heavily on the use of extrapolating yaw rate data generated within the vehicle to produce a prediction of the path of the road ahead. This use of historical data is only satisfactory if the road trajectory is uniform. Sudden discontinuities in the path, such as bends, cause this method of path prediction to produce significant errors.

The shear size and flexibility of the larger airframe parts makes it difficult to imagine assembly without extensive use of hard tooling. Yet, the world of aerospace manufacturing is changing. It is already possible to considerably reduce the amount of external, ‘hard tooling’, especially jigs, through innovative design and the applications of advanced technologies. Jigless Aerospace Manufacture, (JAM), is not a single, mysterious, as yet undiscovered technology. Rather it is a growing number of related and linked technologies. Many of these are already well established and considered ‘robust.’ This paper sets out to review and describe some of these enabling technologies and to explain their individual roles towards achieving JAM.

Unique and groundbreaking—this highly-anticipated book addresses both basic and advanced concepts critical for the understanding and support of the developing field of Integrated Vehicle Health Management (IVHM). From an initial idea by the SAE IVHM Steering Group, collaboratively written by experts from academia, research and industry, the thirteen chapters within this book represent the collective voice of the most qualified authorities in the field. Highlights of the book include: -a single definition and taxonomy of IVHM, as well as basic principles -the identification of how and where IVHM should be implemented -the commercial value of IVHM -vehicle health management systems engineering -algorithms and their impact on IVHM -IVHM future directions and issues -Case study on IHUMS This book serves as the perfect introduction to IVHM for engineers, executives, academic instructors, and students.

Different feasibility studies have been carried out over several years at the Royal Military College of Science (RMCS) into medium military airlifters aimed, in essence at replacing the C-130. The studies, each occupying a nominal 1,500 manhours (but probably 50% more) formed part of the final year of the AeroMechanical B.Eng degree at RMCS. The intention of this paper is to draw together their major findings and deals predominantly with the topics of: cargo hold sizing and body aerodynamics, powerplant selection, weight and performance.

The field of parallel kinematics was viewed as being potentially transformational in manufacturing, having multiple potential advantages over conventional serial machine tools and robots. However, the technology never quite achieved market penetration or broad success envisaged. Yet, many of the inherent advantages still exist in terms of stiffness, force capability, and flexibility when compared to more conventional machine structures. Deployment of Parallel Kinematic Machines in Manufacturing examines why parallel kinematic machines have not lived up to original excitement and market interest and what needs to be done to rekindle that interest. A number of key questions and issues need to be explored to advance the technology further. Click here to access the full SAE EDGETM Research Report portfolio.

Modelling of conflicts between cars and pedestrians is presented in the paper. The model looks at how the velocities and distances change over the time between the pedestrian when first sensed and a potential impact, taking account of how the vehicle speed may be changing due to braking, wheel slip etc. Further work is outlined looking at the probability of conflict resolution behaviour by drivers and pedestrians. The paper also reviews current sensor technology appropriate for detecting pedestrians in front of a moving vehicle. A sensor system is required that responds to the road environment in real-time, and intelligently analyses the data so as to predict potential collisions and determine the nature of such collisions. A detection system combining radar detection with passive infrared detection and classification is proposed as a possible solution, meeting the requirements determined by conflict modelling and a review of the operating environment.

An accurate simulation of a ground vehicle interacting with a crosswind gust can be achieved by using a moving model mounted on a track such that it can traverse the working section of a conventional atmospheric boundary layer wind tunnel. This paper will briefly describe the facility that is being developed at Cranfield University and detail comparisons between static and dynamic data from tests on three basic model configurations. Under the same nominal wind input, data from static tests compares well with that from dynamic tests at yaw angles below 15°. At higher yaw angles, after the onset of “large scale” separation, the dynamic values of the forces and moments become larger than the static values.

Identifying the most appropriate powertrain technology for a given vehicle class and duty cycle can be beneficial to further drive down on carbon emissions. However, with a myriad of powertrain architectures that are emerging in the industry, such as those in Electric Vehicles and Hybrid Vehicles, it becomes more challenging to carry out comprehensive comparative analyses across different permutations of powertrain topologies. This has motivated the authors to research on improving the method used to compare different types of powertrain architectures, and develop a tool that can be used by practitioners for this purpose. Literature survey has indicated that whilst there have been many comparisons made between different types of powertrains, such analyses were often carried out by comparing only limited types of architectures at a time.

This paper describes a computer code for conceptual design of mission optimized twin-turboprop Commuter or Regional aircraft. Optimum configurations and flight profiles of such aircraft are determined by coupling this code to an optimization code based on Simulated Annealing. As an example, minimum DOC configurations were determined for 50-seat Regional aircraft for operation over three stage lengths. The DOC per seat-nm and DOC per trip of the optimum aircraft were found to be comparable or significantly (8 to 17 %) lower than the corresponding values for five contemporary 40 to 50 seater aircraft for short stage lengths.

With increasing speeds and the anticipated reduction in weight of modern cars, the issue of crosswind sensitivity is becoming increasingly important. In a previous paper by the same authors, the normal method of testing such aerodynamic characteristics at model scale, using static models at yaw to the freestream, was compared with dynamic testing, in which the model is propelled across a ‘gust’ simulated by a wind tunnel. A direct comparison using a similar gust profile for both static and dynamic tests was made with the conclusion that the simple static test technique was underestimating the true transient loads. Further tests have been carried out, on a generic squareback (or estate) model, during which the effect of varying both the vertical velocity profile and the turbulence intensity within the gust was considered.

The successful completion of aerospace projects usually involves the bringing together of many different specialist skills. The need for the engineer to become multidisciplined is today's reality, but this is becoming increasingly harder to achieve naturally in the working place. Recent industrial drives towards concurrent engineering have revealed a need for just this type of engineer. The 3 year part-time MSc course in Aircraft Engineering was designed to address these needs and was launched with the first intakes of delegates in 1995. The course is modular and students are encouraged to “mix” disciplines, combining topics such as avionics and structural analysis. The course has created skilled specialists and engineering leaders for the future, with improved technical ability and career potential, albeit at the cost of hard work! The course consists of 3 elements, namely:- Lecture courses held in one-week blocks, over the 3 year period. An individual piece of research.