A numerical method is presented for the time optimal control of the race car. The method is then used to perform the role of the driver in numerical simulations of manoeuvres at the limit of race car performance. The method does not attempt to model the driver but rather replaces the driver with methods normally associated with numerical optimal control. The use of constraints on the method is then considered to represent the performance limits of the human driver. The method simultaneously finds the optimal driven line and the driver control inputs (steer, throttle and brake) to drive this line in minimum time. The method is in principle capable of operation with arbitrarily complex vehicle models as it requires only limited access to the vehicle model state vector. It also requires solution of the differential equation representing the vehicle model in only the forward time direction and is hence capable of simulating the full vehicle transient response. The impact of various vehicle parameters on minimum manoeuvre time, driven line and vehicle stability is shown for a number of representative manoeuvres using a quasi-steady state vehicle model. A similar process is then carried out to analyse the effect of suspension springs and dampers using a fully dynamic sprung vehicle model. The presented transient time optimal control method is then compared with results obtained from a traditional quasi-steady state manoeuvre time simulation method. A thermodynamic tyre model is developed and the time optimal control algorithm is used to evaluate dynamic tyre temperature effects on lap time and vehicle stability.

This thesis presents an investigation of the flow physics governing aerodynamic inter-action mechanisms relevant to Formula One racing cars, in particular the influence of the front wing on the car chassis flat underbody and diffuser. The research has taken a fundamental approach, with emphasis on identifying the fundamental mechanisms governing the interaction. Wake diagnostic techniques have been used to identify the major flow features of the front wing wake that are likely to influence the flat underbody and diffuser. Models have then been designed to simulate these various flow features. A simple model was produced with an underbody which is flat apart from a diffuser over the rear 20% of its length. This was used to simulate the basic flow features of the flat underbody and diffuser of a Formula One car. Wind tunnel measurements of force and surface pressure have been made on this diffuser model with the various upstream models simulating aspects of the front wing wake. It has been found that the downforce generated by the diffuser model is highly sensitive to the configuration of the upstream front wing. Although, for the majority of front wing configurations the downforce generated by the diffuser model was reduced, it was discovered that for certain arrangements the downforce may actually be enhanced. By piecing together the various results gathered over the course of the research, the underlying flow physics involved in the interaction have been identified. Using this information, suggestions are made for how the configuration of the front wing may be optimised for minimum negative impact on the performance of the car underbody and diffuser.

This research aims to investigate the nature of high β-angle cornering as seen in rallying and in particular the World Rally Championship. This is achieved through a combination of sensor development, on-car measurement and vehicle dynamic simulation. Through the development of novel β-angle measurement technology it has become possible to measure and study vehicle attitude dynamics on loose gravel surfaces. Using this sensor, an understanding of how a rally driver uses the dynamics of the vehicle and surface to maximise performance has been obtained. By combining the new data stream with accepted vehicle dynamic theory, the tyres have been considered and general trends in gravel tyre performance unveiled. Through feedback, these trends have been implemented as a means of tuning a dynamic model to improve realism and permit an analysis of cornering trends in rally cars. Active control systems have been considered that could implement more sophisticated algorithms based on this understanding and potentially use the new sensor information as an input signal. A case study which explores such a possibility is included.

Monoposto racecar development is routinely carried out using wheels supported not by the car suspension but by individual, externally-mounted stings. The interference effect of these stings was acknowledged but unquantified in the existing literature. Appraisal of the literature has found that the structure of a wheel wake was not understood, rendering it difficult to assess the support sting interference. These two issues were thus jointly addressed using experimental and computational methods. The two phases of this project each tested a different industrially-representative racecar wheel model. Phase One investigated a single wheel and sting combination, whilst Phase Two extended the work to include two further stings and a model racecar. Non-intrusive velocity measurements were made in the near wakes of the various combinations to extract vertical planes, perpendicular to the tunnel freestream. The measurements made behind the isolated wheels were used to investigate the main flow features of the wake. The flow surrounding an unsupported wheel was established computationally and used to evaluate the interference effects of the support sting. Different wheel support methods (three stings and the car suspension) were used to provide further insight into the sting interference effects and also the impact of sting design on those effects. Testing with and without the model racecar allowed evaluation of its effect on the wheel wake and sting interference. The main characteristics of the near-wake of an isolated wheel rotating in ground contact are proposed from analysis of the data generated in this study. A simplified model of the trailingvortex system induced in the wake of such a wheel is proposed to clarify contradictory literature. The specific interference effects of a wheel support sting are proposed with reference to the main characteristics of the wake. The mechanisms behind these effects are, where possible, identified and presented. The main impact of the support sting, and thus the root of several of the observed effects, is the modification of the axial flow through the wheel. The main effects of the presence of the car on the near-wake are proposed alongside the observation that the wake structure is not fundamentally different to that of an isolated wheel. The proposed sting interference effects are also observed in the presence of the car, albeit at a reduced level.

Racing teams use numerous computational tools (CAD, FEA, CFD) to aid in the design of racing cars and the development of their performance. Computer simulation of racing car handling through Lap Time Simulation (LTS) packages complements these tools. It also allows teams to examine the effect of different vehicle parameter setups to optimise vehicle performance. In similarity with the automotive industry, time is limited and rapid development of new ideas and technology is essential. Thus, the use of a more sophisticated computer simulation would allow a team to gain a significant advantage over their competitors. As LTS are computationally intensive,previous packages have simulateda full lap using a quasi-static method which splits the path of the vehicle into segments. An analysis is then made of the vehicle at each segment point using the external forces acting on the vehicle. Due to the constant acceleration(i.e. steady state) assumption across each segment, this method does not take into account the effect of roll, pitch and yaw inertia as well as damping and tyre lag effects. Another aspect that is not accounted for is the variation in the fastest effective vehicle path along the circuit (i.e.racing line) due to change in driver control inputs or vehicle parameters. The overall aim of this thesis is to develop a transient LTS methodology, which adopts a strategy to vary the racing line taken in order to address the problems found with the existing quasi-static LTS packages. In parallel an investigation of the accuracy of vehicle models in relationship to racing car performance has been developed. The thesis begins with a study of racing car modelling techniques and a review of current LTS packages. A description is then given of the collection of vehicle handlingd ataf rom an actualr acingc ar (alongw ith attaining a vehicle parametesr et) and the measured results displayed and discussed. The creation of two vehicle models, a simple and sophisticated version, is detailed and the measured results are compared to the simulated results of each vehicle model. It was found that the simple vehicle model does not fully represent the actual vehicle's lateral dynamic behaviour, although its steady state response was deemed to be accurate. The sophisticated vehicle model was seen to not only accurately predict the full range of lateral dynamic behaviour of the actual vehicle, but also the actual vehicle's longitudinal and combined lateral and longitudinal dynamic behaviour. To further investigate LTS techniques, a comparison study was made between various simulation approaches which indicated that the transient approach, although more complicated and time consuming, allows for more accurate tuning of a greater number of vehicle parameters. Finally, the creation of two simulation packages has been detailed and case studies are presented to provide further insight into the look and feel of the packages. The first package is a quasi-static approach based LTS package, where a case study is made into the sensitivity of overall lap time to a range of vehicle parameters. The second is a transient approach based simulation package which optimises the driver controls,varying the racing line taken by the vehicle and ensuring the manoeuvre is completed in the quickest time for that vehicle parameter set. This final Manoeuvre Time Minimisation package fulfils the overall aim of the thesis and a case study is made into the effect of front damping value on manoeuvre completion time.

No description available.

The aim of this Engineering Doctorate was to identify and develop strategies and technologies to overcome the barriers to sustainable motorsport. A top-down approach was taken beginning with an industry-wide strategy and ending with the development of individual sustainable technologies. After identifying a set of target guidelines for the industry to follow, the economic, social and environmental barriers to the future sustainability of motorsport were identified. These barriers were addressed through the creation of an industry-wide regulatory strategy followed by an innovative company-focussed technology development process; High Performance Sustainability (HPS). The HPS process was used to develop Eco One, a revolutionary racing car featuring environmentally sustainable technology which generated significant public engagement and facilitated evaluation of the HPS process. This technology demonstrator was used to make iterative improvements to the HPS process, resulting in HPS2, a second generation process with greater focus on performance and the development of sustainable technology. This novel process was used to research and develop individual environmentally-sustainable technologies; natural fibre reinforced composites and the use of high performance biodiesel. Firstly lignin, a natural, renewable, waste material was added to hemp/epoxy composites as an innovative compatibiliser with a resulting improvement in mechanical properties. Secondly, engine parameters were modified for the use of biodiesel made from soybean oil, resulting in torque equal to diesel fuel but with a lower in-cylinder pressure. The impact of these technologies is the opportunity to use renewable materials for high performance applications, potentially competing with existing motorsport technology. The innovations presented in this Engineering Doctorate led to recognised expertise in sustainable motorsport within WMG, and in turn resulted in sustainable motorsport projects including WorldFirst, in which a Formula 3 car was developed featuring natural fibre composites, high performance biodiesel and recycled carbon fibre components. The impacts of this work are the establishment of industrial projects with race teams and constructors, conference attendances and peer-reviewed publications, and dissemination of research through the development of academic courses and extensive media coverage.