Analysing high-speed taxiing for efficient operations at busy airports

Over the past decade Airbus' Landing Gear Systems Group at its UK Filton site has been increasing its use of computer-based modelling and simulation technologies. In this context the use of dynamical systems theory is playing an increasingly important role in identifying stability boundaries quickly and efficiently.

Postgraduate student James Rankin, at the Departments of Engineering Mathematics and Aerospace Engineering at the University of Bristol, started working on the EPSRC CASE Award "Bifurcation analysis of nonlinear ground handling of aircraft" with Airbus UK in October 2006. The project is concerned with developing and applying advanced mathematical and computational tools for the analysis of high-speed taxiing, which is crucial for an efficient operation of aircraft at busy airports.

The mid-term goal of Airbus's research in this area is to develop the requirements for a, potentially, fully automated system that steers an aircraft along the shortest route, orchestrated by Air Traffic Control, as fast as possible between the gate and the runway.

The CASE Award has lead to the Airbus UK funded follow-on project "Analysis of nonlinear ground handling models", which employs a three-year Postdoctoral Research Assistant from April 2007 within the research team at the University of Bristol's Engineering Faculty.

This new project focuses on the stability of tyre/ground interactions under different types of loading, a problem that was presented by Etienne Coetzee of Airbus UK at the Study Group with Industry in April 2006. The problem attracted the interest of academics from eight universities. The one week-long interaction between Airbus and these academics was instrumental to the company taking this research further.

"The Study group provided us with two main outcomes. The immediate outcome was the discovery of the network of people, who were interested in the topic area and were looking to take the study forward. As a result, we set up a 3-year research associateship at the University of Bristol, to extend the study. The by-product is that our relationships, between the University of Bristol and Airbus, are further strengthened." - Sanjiv Sharma, Systems Engineer, Airbus UK

Mathematics to model skeletal muscle's switches from use of lipids to use of glucose

The 2007 Study Group with Industry helped Unilever's Systems Biology group develop a mathematical model that describes skeletal muscle fuel utilisation in humans. This was motivated by an interest in how skeletal muscle switches from utilisation of lipids for fuel in the fasting state to use of glucose in the fed state, and how this metabolic switching varies depending on an individual's insulin sensitivity.

The work of the Study Group with Industry has provided the basis for a cross-faculty PhD project – a BBSRC Industrial CASE Award - at Nottingham University under the supervision of Prof John King (Applied Mathematics) and Prof Ian McDonald (Centre for Integrated Systems Biology and Medicine). At the Study Group the major features of the project were elaborated.

The project looks at a multi-scale model – at the cellular and organ scales - of glucose and fat uptake; in particular it investigates how glucose and fats are processed after eating a meal and how skeletal muscle switches from utilising one source of energy to another - that is from glucose to fats and vice versa. The research is critical in pre-diabetic people where there is a history of resistance to insulin controlled glucose intake.

This research sits within a wider project at Unilever – Systems Biology of Lipid Metabolism – whose scope is to identify novel dietary and lifestyle interventions that can improve heart health using the integrated approaches of systems biology. By better understanding the ultimate switch-line between glucose and fats utilisation and where the switch goes wrong, the value of this CASE project is to reduce cardiovascular disease (each year, 36% of all mortalities in the UK are due to CVD, according to the British Heart Foundation) and to improve people's heart health through appropriate changes in an individual's diet and lifestyle.

"Critically the Study Group also offered an opportunity to familiarise both mathematicians and biologists with the different approaches and ways of working of their respective disciplines in a relaxed but highly productive manner." - Brendan O'Malley, Systems Biology Project Leader, Unilever

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