This project will apply concepts from modern robust control theory to develop algorithms for determining the optimal policy that both achieves sustainable levels of emissions of CO2 (and other greenhouse gases) and minimises the impact on the economy, but also explicitly addresses the high levels of uncertainty associated with predictions of future emissions. The aim of the optimal policy is to adjust factors such as the mix of energy generation methods and policies for reducing emissions from housing, industry and transport, in order to achieve a rate of emissions that will allow the UK to achieve its emissions targets while maximising economic growth as measured by discounted GDP. A key difficulty in determining the optimal policy is handling the uncertainty associated with the effect that the policy changes will have on the rate at which is CO2 emitted. One of the main conclusions of the Stern Review is that policies for stabilisation of CO2 emissions have to be implemented immediately and it is not possible to delay decisions until models with less uncertainty become available. If this conclusion is accepted (and indeed even if it is not) model uncertainty has to be incorporated as an integral part of the design of these policies. Currently, economists are unable to find optimal policies in the presence of uncertainty and most existing economic models address model uncertainty by running repeated what if scenarios to predict the outcome for a range of parameter values. This project will use concepts from robust control theory to develop tools for incorporating uncertainty directly into the design of the optimal emissions policy; the tools can then be applied to other existing models. Including uncertainty within the design quantifies the risk associated with the emissions policy, which allows policy makers and emitters of CO2 to incorporate risk within their strategic plans. The tools will be implemented on the ECCO (Evolution of Capital Creation Options) model that describes the dynamic evolution of CO2 levels emitted by UK economy. Unlike many other economic models, this model is based on the physical principles of mass and energy balances, which are used to derive economic measures.

It is now an accepted fact that the disruption and economic losses arising as a result of extreme storms are increasing at a significant rate. There is also tentative evidence to suggest that these storms are increasing in frequency and magnitude due primarily to climate change effects, although it is acknowledged that such evidence is far from conclusive. Any increases in magnitude and frequency of extreme storms are likely to result in serious damage to the urban infrastructure, the world economy and society as a whole. In European terms, it has been suggested that by 2080, there will be an increase in wind-related insured losses from extreme European storms by at least....25-30bn Euro. However, it is perhaps worth noting that these estimates do not take into account society's increasing exposure to extreme storms, due to growing populations, wealthier populations and increasing assets at risk. Over the last few years there has been renewed interest in the effects of extreme wind events, since in a number of cases these events are the most important with respect to wind loading (i.e., the design of buildings/infrastructure). One particular set of extreme wind events which has received little attention in the past are those associated with thunderstorm downbursts. During a downburst a column of air moves vertically downwards and impinges on the ground. This causes the resultant air to be displaced radially outwards from the point of impingement, with a ring vortex travelling away from the stagnation point. The effect of this is to alter the velocity field significantly. In other words, the velocity field which was assumed when the building was designed may no longer occur, and a new, very different field may exist. The effect that this new wind field has on typical structures has yet to be addressed. Hence, there is a need to undertake a comprehensive examination of the structure of thunderstorm downbursts and to investigate the corresponding wind induced forces which can arise. The scarcity of full-scale data and the difficulty of predicting such events ensure that at present, modelling is a sensible way forward. Furthermore, the uncertainties associated with both physical and numerical modelling strongly suggest that a combined physical/numerically modelling programme supplemented by (limited) full-scale data is the best way forward. Without such an examination of the wind field associated with thunderstorm downbursts, the suitability of existing design methods remains an open question. This is of importance since in many parts of the world wind speeds of this origin constitute the design wind speeds. Even in areas where these events are not dominant, the continued investment and development in society and its related infrastructure ensures that society as a whole is more vulnerable to the effects of such an event irrespective of how frequently they current occur.

Most fire deaths are associated with the remote transport of toxic products produced in hot post-flashover fires, and with carbon monoxide (CO) in particular [S1, S2]. Currently, numerical tools are effective at describing the transport of these toxic products, but incapable of accurately predicting the quantities generated in a fire - thus the source is missing [S2, S3]. In order to extend the scope of fire safety engineering (FSE) methods, and provide more effective tools for practitioners, there is an urgent need for robust and well-validated methodologies which address the problem in its entirety, thus completing the chain and provided a true predictive capability [S3]. This would open the door to a host of new applications, including fire forensics to assist in determining causes of fatalities, supplementing expensive full-scale fires tests, and ultimately in building design, and could transform the application and exploitation of FSE methodologies. It is essential that any such methodology can be effectively exploited by the fire community, so it must be undemanding computationally (so that it can be run on computers typically used by consultants) and must effectively accommodate the specific requirements of real-world fires, i.e. large-scale building scenarios involving a very broad range of lengthscales, and multiple and often complex fuel sources, where significant contributions to toxic products yields may arise both from complex formation processes in the gas phase and directly from the solid-phase, via pyrolysis of combustible boundary materials [S2]. Here an advanced methodology is proposed in which each of these processes can be effectively accommodated, based on the solution of transport equations for each chemical species of interest. The focus of this proposal is on CO prediction, but the method could in future be extended to include other toxic species. The key research question to be addressed is how to most effectively achieve chemical source term closure which is the essential modelling challenge in turbulent combustion systems. Different approaches will be investigated, including a fundamental method based on directly solving the coupled species balance equations using simplified quasi-laminar expressions, and a more sophisticated method which is an extension of the flamelet modelling approach. These predictions will be benchmarked against existing approaches which rely on conventional flamelet representations of toxic product yields and extensions to the simple eddy breakup concept approach, as described in the literature [S4]. The new methods will be validated against relevant experimental data from realistic fire scenarios designed to fully test the generality of the new modelling strategies [S2, S3, S5]. Detailed recommendations will be prepared on exploitation of the methodology, considering the fundamentally competing demands of computational resources and accuracy.References========S1. Babrauskas, V., Levin, B. C., Gann, R. G., Paabo, M., Harris, Jr, R. H., Peacock, R. D. & Yusa, S. (1991) Toxic potency measurement for fire hazard analysis , Special Pub. 827, NIST, Dec 1991S2. Pitts, W.M. (1995) The Global Equivalence Ratio concept and the formation mechanisms of carbon monoxide in enclosure fires , Prog. Energy Combust. Sci., vol. 21, pp. 197-237S3. Purser, D. & Purser, J. (2003) The potential for including fire chemistry and toxicity in fire safety engineering , BRE Client report 202804, 26 Mar 2003S4. Hyde, S.M. & Moss, J.B. (2003) Modeling CO production in vitiated compartment fires , Proc. 7th Int. Symp. Fire Safety Science, pp. 395-406 S5. Smith, D.A., Marshall, N., Shaw, K., & Colwell, S. (2001) Correlating large-scale fire performance with the Single Burning Item test , Proc. 9th Int. Interflam Conf., pp. 531-542

SUMMARYUnderstanding structural behaviour of buildings during a fire is accepted as being essential to make full use of the recently introduced performance-based design codes. However, currently the behaviour of buildings during the cooling phase of a fire is poorly understood. Evidence from full-scale tests and real fires has shown that collapse of buildings can occur during the cooling stage of the fire, which can compromise the safety of firefighters and the public in the proximity of the building. This joint project between Manchester and Edinburgh University, will investigate the behaviour of cooling steel-concrete composite structures to gain an understanding of their behaviour and the underlying mechanics. The project includes testing of composite slabs, subject to different axial restraint conditions and natural fire scenarios, to obtain a unique understanding of forces generated within the structure during the cooling stage of a fire. Working in parallel to the experimental phase of the project, existing numerical models will be extended to simulate structural behaviour during the cooling phase. Once validated, the numerical models will allow an understanding of the behaviour of complete structures during the full duration of the fire, significantly advancing the current modelling capabilities which concentrate on the behaviour up to the fire's estimated maximum temperature. The results from the complex models, together with the experimental results, will allow simple design rules to be developed to ensure that buildings do not collapse during the cooling stage of the fire, thus ensuring the required level of safety for both firefighters and the public.

Understanding structural behaviour of buildings during a fire is accepted as being essential to make full use of the recently introduced performance-based design codes. However, currently the behaviour of buildings during the cooling phase of a fire is poorly understood. Evidence from full-scale tests and real fires has shown that collapse of buildings can occur during the cooling stage of the fire, which can compromise the safety of firefighters and the public in the proximity of the building. This joint project between Manchester and Edinburgh University, will investigate the behaviour of cooling steel-concrete composite structures to gain an understanding of their behaviour and the underlying mechanics. The project includes testing of composite slabs, subject to different axial restraint conditions and natural fire scenarios, to obtain a unique understanding of forces generated within the structure during the cooling stage of a fire. Working in parallel to the experimental phase of the project, existing numerical models will be extended to simulate structural behaviour during the cooling phase. Once validated, the numerical models will allow an understanding of the behaviour of complete structures during the full duration of the fire, significantly advancing the current modelling capabilities which concentrate on the behaviour up to the fire's estimated maximum temperature. The results from the complex models, together with the experimental results, will allow simple design rules to be developed to ensure that buildings do not collapse during the cooling stage of the fire, thus ensuring the required level of safety for both firefighters and the public.