In many scientific and industrial situations, it is important to predict whether a small perturbation in a flow will grow (unstable flow) or decay (stable flow). Industrial applications of stability theory include: the break-up of the jet in an ink-jet printer; large scale mixing in a combustion chamber; thermo-acoustic oscillation in a gas turbine; coupled mode flutter of a wind turbine and mixing in small channels for pharmaceutical applications. The conventional technique is to decompose the perturbation into modes that are normal (i.e. orthogonal) in two spatial dimensions and to study the growth of each mode separately. This, however, often gives inaccurate results. As a simple example, this technique predicts that the flow in a pipe will be stable at all Reynolds (Re) numbers (i.e. at all velocities). In reality, however, the flow becomes turbulent at Re ~ 2000, depending on external noise and the pipe's roughness.This discrepancy arises because, in the third spatial dimension, the modes are non-normal (i.e. non-orthogonal). This means that they can feed energy into each other and should not be considered separately. This non-normal behaviour often causes strong transient growth at the intermediate times that are of most interest to scientists and engineers. For instance, in pipe flow, a non-normal analysis predicts that tiny perturbations will rapidly develop into stream-wise streaks at Re ~ 2000, agreeing with experimental evidence. In the last decade, there has been a surge of interest in non-normal stability analysis within the applied maths community. It is widely thought that non-normality is the root cause of the transient behaviour of the simple flows they have analysed. The aim of this network is to accelerate its exploitation in more complex flows, particularly those with industrial relevance. Conventional stability analyses are currently applied to many industrial situations and, as for simple flows, could miss some of the most significant behaviour.Non-normal analyses, as well as being more accurate, also predict the regions of a flow that are most influential in creating a desired result, such as good mixing. With development, this information will allow engineers to design 'backwards' from an end result, rather than 'forwards' by trial and error. Our long term vision is that the next generation of Computational Fluid Dynamics tools will contain modules that can perform non-normal stability analysis. An important goal is to distinguish between the situations in which a non-normal analysis is required and those in which a conventional analysis is sufficient. We will do this both by reviewing the canonical flows, such as jets/wakes, pipe flow, boundary layers and thermo-acoustic oscillations in a Rijke tube, and by accelerating work on a number of industrial case studies.To achieve this, we will create a multi-disciplinary international network with both academic and industrial partners. The technical goals will require a broad range of expertise: mathematical, to retain the understanding developed for the canonical flows; numerical, to perform the high order computations that will be necessary when moving from simple to complicated flows; experimental, to assemble a catalogue of evidence that will demonstrate when the technique is more relevant than normal mode analysis. The network will expand to a broader industrial community as the ranges of applicability becomes clearer. Currently, several groups are working in this area but, in this relatively young field, there is little formal interaction between them. The network will build on the UK's traditional strength in flow instability and incorporate partners from India, where there has recently been some outstanding work in non-normal analysis. The network will start with one very significant overseas partner (Peter Schmid from Ecole Polytechnique, France) and expand internationally during the two year start-up period.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

This research project addresses the process industry contribution to the UK government goals of tackling climate change and reducing dependence on imported fuel. This programme fills these nationally important objectives by investigating the short, medium and long-term provision of energy for the UK, based on thermal technologies that exploit low grade process heat that is currently not recovered by this industry. The results of this 'Whole Systems Analysis research will improve plant efficiency and displace a significant fraction of fossil fuel use, thus reducing UK carbon dioxide emissions, by using techniques that are secure, clean, affordable and socially welcome. This research involves collaboration between several highly relevant industrial partners (e.g. Corus Ltd, North East Process Industry Cluster (NEPIC) Ltd, EON UK, Veolia (Sheffield Heat & Power Ltd), Pfizer Ltd, etc) and four internationally leading academic centres of excellence (Universities of Sheffield, Newcastle, Manchester & Tyndall Centre). The research programme targets a national problem by exploiting their complementary expertise through Whole Systems Analysis . Thus the objective of this research proposal is to investigate new and appropriate technologies and strategies needed for industry to exploit the large amount of unused low grade heat available. This will be achieved by providing a systematic procedure based on a comprehensive analysis of all aspects of process viability that will enable industry to optimise the management and exploitation of their thermal energy. This detailed procedure will be backed up by a sustained channel of communication between the relevant industrial and academic parties. This multidisciplinary work is thus applicable both to existing plants and the design of future plants. Please note that the establishment of an associated but separately funded EPSRC Network (e.g. PRO-TEM) is considered to be an integral part of this project, in order to satisfy the implicit role of technology transfer in both directions, between the process industry and the wider academic community. It will also provide access to industrial players who will provide essential case studies for the technical and socio-economic work. The case for an associated PRO-TEM Network is briefly discussed herein and the case is presented in detail in a separate proposal by Newcastle University.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.