During their daily lives, human beings constantly interact with their immediate environment. The environment affects human well-being, comfort, and performance. In turn, humans cause changes in temperature, air movement, relative humidity, odour and C02 concentration within the surrounding air.Naturally ventilated (NV) buildings are an energy efficient alternative to mechanical ventilation and air-conditioning. However, the energy consumption and the effectiveness of a natural ventilation system depends on occupant behaviour. On the other hand, occupant comfort in NV buildings can be compromised because the indoor environment is strongly linked with the outdoor weather conditions and vary throughout the space due to draughts, solar gains and warm air stratification.The aim of the project is to develop a validated simulation tool capable of predicting the human-environment interactions in NV buildings and so to predict the impact of building designs on occupants and vice versa. The research will combine a detailed computer model for predicting airflow and temperature patterns in buildings (computational fluid dynamics or CFD) with a detailed mathematical model of human physiology and thermal comfort. The heat and moisture exchange processes within the buoyant plume that surrounds the human body and the micro-climatic conditions within this plume will be modelled in detail. It is hoped that the work will establish important new knowledge which is essential for a better understanding of the impact of human beings on the design and the performance of NV buildings. The research will bring the human occupancy factor further into the core activities of the design process of buildings.The research will extend the prediction capability of CFD and reveal the complex human-environment interactions and phenomena affecting occupant comfort not only in NV buildings, but also in other areas of human activity and endeavour such as health (e.g. the transfer of infection agents, and indoor air quality), safety (e.g. firefighting), and in the design of cars, trains and aircraft.

During their daily lives, human beings constantly interact with their immediate environment. The environment affects human well-being, comfort, and performance. In turn, humans cause changes in temperature, air movement, relative humidity, odour and C02 concentration within the surrounding air.Naturally ventilated (NV) buildings are an energy efficient alternative to mechanical ventilation and air-conditioning. However, the energy consumption and the effectiveness of a natural ventilation system depends on occupant behaviour. On the other hand, occupant comfort in NV buildings can be compromised because the indoor environment is strongly linked with the outdoor weather conditions and vary throughout the space due to draughts, solar gains and warm air stratification.The aim of the project is to develop a validated simulation tool capable of predicting the human-environment interactions in NV buildings and so to predict the impact of building designs on occupants and vice versa. The research will combine a detailed computer model for predicting airflow and temperature patterns in buildings (computational fluid dynamics or CFD) with a detailed mathematical model of human physiology and thermal comfort. The heat and moisture exchange processes within the buoyant plume that surrounds the human body and the micro-climatic conditions within this plume will be modelled in detail. It is hoped that the work will establish important new knowledge which is essential for a better understanding of the impact of human beings on the design and the performance of NV buildings. The research will bring the human occupancy factor further into the core activities of the design process of buildings.The research will extend the prediction capability of CFD and reveal the complex human-environment interactions and phenomena affecting occupant comfort not only in NV buildings, but also in other areas of human activity and endeavour such as health (e.g. the transfer of infection agents, and indoor air quality), safety (e.g. firefighting), and in the design of cars, trains and aircraft.

Uncertainty is ubiquitous in the mathematical characterisation of engineered and natural systems. In many structural engineering applications, a deterministic characterisation of the response may not be realistic because of uncertainty in the material constitutive laws, operating conditions, geometric variability, unmodelled behaviour, etc. Ignoring these sources of uncertainties or attempting to lump them into a factor of safety is no longer widely considered to be a rational approach, especially for high-performance and safety-critical applications. It is now increasingly acknowledged that modern computational methods must explicitly account for uncertainty and produce a certificate of response variability alongside nominal predictions. Advances in this area are key to bringing closer the promise of computational models as reliable surrogates of reality. This capability will potentially allow significant reductions in the engineering product development cycle due to decreased reliance on extensive experimental testing programs and enable the design of systems that perform robustly in the face of uncertainty. The proposed investigation will address this important research problem and deliver convergent computational methods and efficient software implementations that are orders of magnitude faster than direct Monte-Carlo simulation for predicting the response of structural systems in the presence of uncertainty. This work will draw upon developments in stochastic subspace projection theory which have recently emerged as a highly efficient and accurate alternative to existing techniques in computational stochastic mechanics. The overall objectives of this project include: (1) formulation of convergent stochastic projection schemes for predicting the static and (low and medium frequency) dynamic response statistics of large-scale stochastic structural systems. (2) design and implementation of a state-of-the-art parallel software framework that leverages existing deterministic finite element codes for stochastic analysis of complex structural systems, and (3) laboratory and computer experiments to validate the methods developed. The methods to be developed will find applications to a wide range of structural problems that require efficient and accurate predictions of performance and safety in the presence of uncertainty. This is a crucial first step towards rational design and control strategies that can meet stringent performance targets and simultaneously ensure system robustness. Progress in this area would also be of benefit to many other fields in engineering and the physical sciences where there is a pressing need to quantify uncertainty in predictive models based on partial differential equations.

A major design consideration for offshore wave energy devices is survivability under extreme wave loading. The aim of this project is to predict loading and response of two floating wave energy devices in extreme waves using CFD (computational fluid dynamics), in which fluid viscosity, wave breaking and the full non-linearity of Navier-Stokes and continuity equations are included. Two classes of device will be considered: Pelamis (of Ocean Power Delivery Ltd.), the prototype having already successfully generated electricity into the grid, and a floating buoy device responding in heave, known as the Manchester Bobber (Manchester University), which is being tested at 1/10th scale. Both classes of device are thought to be competitive with other renewable energy sources, being economically roughly equivalent to onshore wind energy. The CFD simulations will be undertaken in three ways: by commercial codes, CFX and COMET (STAR-CD); by recent advanced surface-capturing codes; and by the novel SPH (smoothed particle hydrodynamics) method. In order to address the uncertainties in the CFD approaches, such as the accuracy of prediction and the magnitude of computer resources required, a staged hierarchical approach of increasing computer demand will be taken in: mathematical formulation (from an inviscid single fluid to a two-fluid viscous/turbulence approach); wave description (from regular periodic to focussed wave groups including NewWave); and complexity of structure (from a fixed horizontal cylinder parallel to wave crests to the six degrees of freedom of Pelamis). At each stage, numerical results will be compared with experimental data. The significance of the inviscid v. viscous formulations, wave nonlinearity, non-breaking v. breaking conditions, and the dynamic response of the body will thus be assessed for extreme conditions. Designs for survivability should thus be better evaluated. The resulting CFD methodology will also benefit analysis of extreme wave interaction with ships, other marine vehicles and structures in general. For example interaction with freak waves and the 'green' water problem have yet to be resolved.

A major design consideration for offshore wave energy devices is survivability under extreme wave loading. The aim of this project is to predict loading and response of two floating wave energy devices in extreme waves using CFD (computational fluid dynamics), in which fluid viscosity, wave breaking and the full non-linearity of Navier-Stokes and continuity equations are included. Two classes of device will be considered: Pelamis (of Ocean Power Delivery Ltd.), the prototype having already successfully generated electricity into the grid, and a floating buoy device responding in heave, known as the Manchester Bobber (Manchester University), which is being tested at 1/10th scale. Both classes of device are thought to be competitive with other renewable energy sources, being economically roughly equivalent to onshore wind energy. The CFD simulations will be undertaken in three ways: by commercial codes, CFX and COMET (STAR-CD); by recent advanced surface-capturing codes; and by the novel SPH (smoothed particle hydrodynamics) method. In order to address the uncertainties in the CFD approaches, such as the accuracy of prediction and the magnitude of computer resources required, a staged hierarchical approach of increasing computer demand will be taken in: mathematical formulation (from an inviscid single fluid to a two-fluid viscous/turbulence approach); wave description (from regular periodic to focussed wave groups including NewWave); and complexity of structure (from a fixed horizontal cylinder parallel to wave crests to the six degrees of freedom of Pelamis). At each stage, numerical results will be compared with experimental data. The significance of the inviscid v. viscous formulations, wave nonlinearity, non-breaking v. breaking conditions, and the dynamic response of the body will thus be assessed for extreme conditions. Designs for survivability should thus be better evaluated. The resulting CFD methodology will also benefit analysis of extreme wave interaction with ships, other marine vehicles and structures in general. For example interaction with freak waves and the 'green' water problem have yet to be resolved.