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Aeroelastic phenomena such as flutter can have a detrimental effect on aircraft performance and can lead to severe damage or destruction. Buffet leads to a re- duced fatigue life and therefore higher operating costs and a limited performance envelope. As such the simulation of these aeroelastic phenomena is of utmost importance. Computational aeroelasticity couples computational fluid dynamics and computational structural dynamics solvers through the use of a transforma- tion method. There have been interesting developments over the years towards more efficient methods for predicting the flutter boundaries based upon the sta- bility of the system of equations. This thesis investigates the influence of transformation methods on the flutter boundary predition and considers the simulation of shock-induced buffet of a transport wing. This involves testing a number of transformation methods for their effect on flutter boundaries for two test cases and verifying the flow solver for shock-induced buffet over an aerofoil. This will be followed by static aeroelastic calculations of an aeroelastic wing. It is shown that the transformation methods have a significant effect on the predicted flutter boundary. Multiple transformation methods should be used to build confidence in the results obtained, and extrapolation should be avoided. CFD predictions are verified for buffet calculations and the mechanism behind shock-oscillation of the BGK No. 1 aerofoil is investigated. The use of steady calculations to assess if a case may be unsteady is considered. Finally the static aeroelastic response of the ARW-2 wing is calculated and compared against ex- perimental results.

This thesis sets out an interpretation of the value of community that I call communal reciprocity. It charts the history of that ideal, analyses its use in the work of an important academic proponent, G.A. Cohen, and develops a more comprehensive account of its main features. It also discusses the implications of communal reciprocity, including whether or not it conflicts with certain freedom-based concerns and its application, including in the assessment of market economies.

If we are interested in questions about how we ought to organize our political lives, what kind of weight, if any, should we give to evidence about what people actually think? The thesis explores this question about the role of public opinion in normative political theory. First, I disentangle a number of distinct justifications for taking account of public opinion. Specifically, the thesis evaluates four views of the status of public opinion: as an epistemic resource; a feasibility constraint; a means of democratizing political theory; or constitutive of moral and political ideals. I defend the epistemic argument, outlining two forms in which popular attitudes represent a valuable epistemic resource. The thesis criticizes the feasibility and democratic accounts of the role of public opinion as these are presented in the existing literature, but suggests more convincing ways of reconstructing these arguments. Finally, I reject the view that public opinion constitutes the ideal of justice, arguing that such an account is subject to a fundamental tension. As well as clarifying the status of popular attitudes, the thesis addresses the methodological difficulties that arise when we seek to bring public opinion to bear on ideas from political theory, whose meaning and status in everyday political thought and discourse is often limited or uncertain. I outline two approaches to integrating normative theory with the investigation of popular attitudes that mitigate the methodological problems that often confront such projects. The second major aim is to situate the question of the role of public opinion in the context of wider debates about the aims and methods of contemporary political theory. In particular, I address recent demands for greater ‘realism’ in political theory, distinguishing two main strands of realist critique and drawing out their contrasting implications for the role of public opinion.

The problem of legitimate authority is widely regarded as fundamental to moral and political philosophy. This thesis aims to explain what the problem precisely is, and to offer a practical method for solving it. The starting point is a claim about the phenomenology of the person as an inherently authoritative agent: we are persons, as distinct from mere ‘things’, by virtue of the authority we possess over ourselves. This claim explains, I argue, why there is a problem of legitimate authority – why the exercise of state authority stands in need of justification – and what the problem precisely is: given the inherent tension between the authority of the state on the one hand, and the self-governing authority of persons on the other, the problem of legitimate authority is essentially that of creating the conditions for optimal reconciliation between them. The bulk of the thesis is devoted to a search for a solution to this problem. The ideal solution lies in developing a concept which I call the Authorization Principle. In its most basic form, the principle states that the exercise of state authority is legitimate only when it is exercised to enforce arrangements that all citizens authorize the state to enforce. The conclusion of the thesis is that the principle should be formulated as follows: The exercise of state authority is legitimate insofar as it is exercised within the provisions of a constitutional arrangement constructed through a process that gives equal weight to all the epistemically undefeated concerns in the society regarding the conditions necessary for persons to exercise personal authority. The solution proposed in the thesis for the problem of legitimate authority has three important implications. The first is that it is entirely within the capacity of ordinary democratic societies to solve the problem. The second is that there is no single legitimate way to govern a society. Standards for the legitimate use of state authority are in some way indexed to culture, ability and resources as well as to other aspects of a society’s unique circumstances. The third is that a society cannot settle the problem of legitimate authority once and for all. The state’s arrangement will require revision every so often in order to maintain the legitimacy of state authority.

This thesis defends a conception of equality of opportunity. It comes in two parts. The first part elaborates the conception. It begins by clarifying the concept of equality of opportunity, showing it to be made up of four basic elements: a distributive pattern, a set of subjects, an opportunity obstacle and a distributive object. The conception I build from these elements explains the value of the distributive pattern, equality, in terms of a concern for fairness, takes persons as its subject and takes well-being as its object. The conception presented is partial, rather than comprehensive, in that it does not include a detailed account of an opportunity obstacle. The conception of equality of opportunity that I present can also be characterised as a luck egalitarian principle. My aim in elaborating the conception is to show that it has intuitive appeal; it constitutes a pro tanto moral principle. The second part of the thesis examines the implications of luck egalitarianism in two contexts. It begins by examining the context of gifts, arguing that although luck egalitarianism is highly restrictive with respect to the freedom to give this only confirms that it is a merely pro tanto moral principle. It continues by examining the context of markets, arguing that luck egalitarianism makes intuitively correct judgments in several specified cases. My aim in applying luck egalitarianism is to show that its implications do not give us reason to reject its initial intuitive appeal. I examine luck egalitarianism generally, rather then the partial conception I elaborate, to allow for the possibility that my earlier arguments are wrong in some respect. Overall, I hope the arguments presented provide reasons to accept the conception presented as morally valuable.