This thesis promotes the responsible use of CFD technology through the development of the simulation based design strategy applicable to the design of the tire engineered smoke control ventilation systems. The correct representations of the problem of interest and measures that may be adopted to ensure the accuracy of the simulated solution are two key aspects of this promotion. The development process presents the application of the proposed procedure through three industrial challenges that have subsequently been approved by the relevant fire authorities. The challenges consist of the design of fire engineered systems for residential high rise buildings and covered car parks which in turn demonstrate the robustness of the proposed procedure. The proposed procedure consists of four key stages namely: Qualitative Design Review (QDR); Quantitative Analysis (QA); Assessment; and Fire Services' comments. QDR identifies the ventilation strategy, the potential tire scenario and the appropriate assessment approach applicable to the problem of interest. QA uses the chosen tire analytical approach to evaluate parameters identified in the QDR. The assessment stage is where outputs from the analysis are assessed based on the assessment criteria defined in the QDR. Fire Services' comments are there to account for any additional requirements the fire officer responsible might had have as he/she has the final say on whether the fire engineered system is approved for installation. A review of the current legislative literature i.e. building code, prescriptive and performance based codes is presented. Furthermore, the criteria applicable for the assessment of simulation based design solution are also discussed. The concept of smoke control is discussed in detail which includes an overview of the mechanism of smoke movement and the provisions available to limit smoke spread. A survey of the current Computational Fluid Dynamics (CFD) software packages suitable for the assessment of smoke movement is also included.

In terms of developing knowledge to enable more effective use of performance based engineering (PBE), one of the key limitations is the lack of an easy to use integrated computational tool that is also robust and comprehensive enough to enable automated modelling of more realistic fire scenarios, i.e., the structural response to localised or travelling fires. The main objective of this thesis is to establish such an integrated computational tool, which shall be based on the OpenSees software framework and facilitated by specially developed approaches to achieve higher efficiency of the integrated analysis. This includes the analysis of heat transfer from the fire to structural members, as well as the analysis of structural response to elevated temperatures during the fire. In this thesis, the research begins with the investigation of the feasibility of dimensional reduction for heat transfer analyses of structural members subjected to localised fire action (SFPE and Eurocode 1 fire models), which can be numerically represented by a linear or exponential correlation between incident heat flux and radial distance. Accurate estimates of the error induced by dimensional reduction are presented under strongly varying localised heat fluxes that represent the most non-uniform fire conditions in a building compartment. It is shown that beams and slabs can be adequately modelled with a lower dimensional heat transfer analysis for ordinary building fires. Using this approach, the complexity of heat transfer modelling and the required computing resource and user effort can both be significantly reduced, especially in cases where structural members are subjected to localised fire action. Thermo-mechanical simulations are presented to address the behaviour of structural members subjected to localised fire action, for which a ThermalAction- Wrapper is developed to approximate the temperature distribution from a mixed-order interpolation between sections (beam) or locations (slab). For concrete slabs subjected to localised fire, MITC4 based shell elements are used to account for material and geometric nonlinearities. An integrated simulation environment is developed, which is designed to be a computational tool that requires limited input but provides a comprehensive solution to the problem of simulating large structural frame and sub-frame response under realistic fire scenarios. A considerable amount of code has been written to create and operate the building model, and to process the heat fluxes from the design fires to the structure and the consequential structural response to the evolution of temperatures within it. Parametric studies have been performed to investigate the computational performance of the newly developed elements in modelling beams and slabs subjected to different cases of localised fire action. The results suggest that 3 to 6 force-based beam elements can adequately describe the localised response however more elements are required for quadratic distribution of incident heat flux and higher temperatures, which is due to the degradation of material strength that governs the accuracy especially when the members are heavily loaded. For slabs exposed to localised fires, centre fires are found to produce greater deflections than corner fires, while lateral restraints applied to the slabs may also lead to higher deflections. A small-scale three dimensional structural frame is modelled as a demonstration of the tool, tested against a number of localised fire scenarios. The global behaviour of the structure with the local effects induced by the fire action and partially damaged fire protection are investigated. Severe damage can be found in the members exposed to a single whole compartment fire, in contrast with the relatively small deflections that are observed when a fully protected column is engulfed by a localised fire. However if the passive fire protection is partially damaged, collapse may occur in the column as a result of load magnification because of the redistribution. To the author's knowledge this is the first piece of research that has been able to develop a practically feasible approach to enable efficient coupled computation of the response of structural frames to realistic fire scenarios on a freely available open source software platform. Currently this kind of analysis can only be carried out by just two or three large consulting firms because of the prohibitive commitment of analyst time and effort and to a lesser extent the need for significant computing resources. The work of this thesis will contribute enormously towards making high-end performance based engineering of structural fire resistance a much more practical proposition for small and medium size structural consultancies. Furthermore, the choice of OpenSees, which is a very well respected software framework for simulating structural response to earthquakes naturally enables this work to be extended to the simulating the multi-hazard structural resistance, such as in the event of a fire following an earthquake which may have locally damaged passive fire protection.

Concentrations of selected PFRs were determined in indoor dust from cars, couches, living rooms, offices, and school classrooms in Australia, Canada, Germany, Kazakhstan, and the UK. Significant differences were found between concentrations of PFRs in dust from different microenvironment categories in the same country. Assessment of human exposure via dust ingestion, revealed the majority of exposure to most PFRs occurs in the domestic environment. However, exposure to TDCIPP occurs primarily in cars, and a substantial proportion of the exposure of young children to EHDPP occurs in classrooms. Reassuringly, the exposure estimates in this study are at least 2 orders of magnitude below health based limit values reported in the literature. However, improved characterisation of exposure to TCIPP via inhalation is identified as a research priority. To address the substantial uncertainty in existing values reported for PFR vapour pressures, they were determined experimentally via the GC-RT method. For most target PFRs, results showed good overall agreement with the mean of experimental and \(in\) \(silico\) literature values. However, values for the chlorinated PFRs exceeded the average of literature values.

The UK Health & Safety Executive are responsible for advising on ways to ensure the safety of employees within the workplace. One of the main areas of concern is the potential problem of unwanted fire, and it has been identified that within the area of large-scale storage in warehouses, there is an uncertainty posed by large quantities of thermoplastic. Some forms of thermoplastic exhibit melt-flow behaviour when heated, and a large vertical array exposed to a fire may melt and ignite forming a pool fire in addition to a wall fire. This project is largely experimental, and aimed at quantifying the effect of a growing pool fire fuelled by a melting wall on overall fire growth rate. The pool fire has been found to increase melting and burning rates, producing a much faster growing fire. It has also been found that - 80% of flowing and burning material will enter a potential pool fire, with only 20 - 25% of total mass loss actually burning from the original array. During the project 400+ small-scale tests and several medium-scale experiments have been undertaken at both Edinburgh University and the HSE's Fire & Explosion Laboratory, Buxton. The experiments have confirmed the main parameters governing pool fire development are molecular weight degradation rate and mechanism, which control flow viscosity. There have also been investigations into other influences, the most significant of which was found to be flooring substrate. These parameters then form the basis of a simple 1-D model. A semi-infinite heat transfer approximation is used to determine temperature profile through a thermoplastic exposed to its own flame flux, with extrapolated temperature dependant material properties. The derived profile is then inserted into a gravity driven flow model, to produce estimates of flow rate and quantity for plastics undergoing either random or end chain scission thermal degradation processes. The model identifies property data which are required to permit its use as a hazard assessment tool.

Region specific foods in the Niger Delta like yam and cassava are consumed on a daily basis by at least 70% of the population. In addition to other commonly consumed foods, high volumes of unavoidable food wastes are generated. With 78% of the households in the region disposing their waste by burying, burning or in unauthorised heaps, environmental degradation is sustained. The region also suffers an infestation of Water Hyacinth (WH). Anaerobic Digestion (AD) presents a viable way of managing these wastes in addition to providing a clean source of energy. Limited research has been conducted on the characterisation and biogas potential of these exotic food wastes due to their localised availability, leading to a knowledge gap. My original contribution to knowledge is the Specific Waste Index (SWI), nutrient characterisation and biogas potential of the local food wastes and WH. Also novel is the design and optimisation of the AD process for mono and codigestion including the quarter hourly analysis of CH4 and CO2 content of the biogas composition over the complete duration of an AD test. The research approach was experimental and involved using conventional research methods in new fields of investigation. SWI was determined by replicating local food processing practices while nutrient composition was obtained using standard analytical methods. The Bio-Methane Potential (BMP) tests were carried out on the four most common food wastes, Yam Peel (YP), Cassava Peel (CP), Cocoyam Peel (CoP), Plantain Peel (PP), following VDI 4630 guidelines and using a newly designed cost-effective bioreactor. Laboratory scale batch reactors ran over 20 days at 37⁰C (310 K). The food wastes were anaerobically co-digested with WH in the ratio 2:1 g Volatile Solid (VS) with a total substrate mass of 8.4 g VS. The S:I ratio was 1:2 g VS and tests were carried out in duplicates to give an indication of repeatability. The results showed a wide range of SWI from 0.2-1.5. The Total Solid (TS) content varied from 7% for WH to 82% for Egusi Shell. Crude Protein and Crude Fibre were highest for Ugwu Stalk at 37% VS and Egusi Shell at 82% VS respectively. Cassava Peel had the highest oil content at 25% VS. NFE which was the major nutrient for 80% of the samples was highest for Yam Peel at 82% VS. YP+WH, CP+WH, CoP+WH and PP+WH had specific biogas yields of 0.42, 0.29, 0.39, and 0.38 m3/kg VS respectively. The yields represented 76%, 48%, 70% and 69% of their respective theoretical values. The samples had their highest methane content during the Technical Digestion Time (T80) period, which lasted up to the 8th day of digestion. The pH values ranged from 7.3 to 7.9 indicating that there was no inhibitory accumulation of organic acids. The results of the mono-digestion tests showed that co-digestion with WH reduced the biogas yields for YP, CP, CoP and PP by 16%, 22%, 7% and 7%. This drop in gas production was due to presence of complex molecules in the WH co-substrate, which cannot be digested by the anaerobic microbes. Further tests showed that fresh waste produced more biogas than dry samples, while a lower S:I produced more biogas due to increased microbial population. It was concluded that waste and nutrient content varied widely between different types of Niger Delta foods. In addition mesophilic digestion of food wastes have good biogas potentials which reduce when co-digested with water hyacinth. The methane content is shown to vary widely throughout an AD test. The findings of this research would provide valuable information to AD databases and its implementation would support clean energy production, environmental remediation and allow researchers in poor regions to perform BMP test on novel feedstock using cost-effective reactors. Key Words: Anaerobic Digestion, Co-Digestion, Water Hyacinth, Niger Delta, Yam, Cassava, Cocoyam, Food Waste, Specific Waste Index, Biogas.

This thesis describes the development and validation of a modified eddy viscosity model to take into account the misalignment between stress a_{ij} and strain S_{ij} fields for reacting flow. The stress-strain misalignment is quantified by introducing a C_{as}=-a_{ij}S_{ij} /\sqrt{2S_{ij}S_{ij}} parameter. A new transport equation for C_{as} was derived from a full Reynolds stress model (RSM). The C_{as} transport equation was coupled to a standard EVM model (e.g. k-\omega SST) to form three equations model. This model is a new version of the SST-C_{as} model introduced by Revell (Revell2006), to incorporate buoyancy and combustion effects for buoyant reacting flow (e.g. fire). The performance of the proposed model was initially investigated via non-reacting buoyant plumes with different level of unsteadiness. The buoyant plumes were also simulated using different turbulence models and the results were compared to proposed model and experimental data. The model shows significant improvements for velocity and scalar profiles in region closed to plume centreline compared to the original SST model. The SST-C_{as} model was then applied for a real fire test case (Steckler room), and the results were compared to experimental data and results of RSM models. The SST-C_{as} model generally yields better than classical EVM models and reduces the gap between the RSM and EVM prediction with 25-30\% additional computational expenses. This work is still under development and validation for reacting flows, further work is going on to include the turbulence combustion interaction and validate it with DNS data.

Modern buildings increasingly include the usage of innovative materials aimed at improving sustainability and reducing the carbon footprint of the built environment. Phase Change Materials (PCMs) are one such group of novel materials which reduce building energy consumption. These materials are typically flammable and contained within wall linings yet there has been no detailed assessment of their fire performance. Current standard fire test methods provide means to compare similar materials but do not deliver knowledge on how they would behave in the event of a real fire. Thus, the aim of this thesis is to develop a novel testing framework to assess the behaviour of these materials in realistic fire scenarios. For PCMs, a flammability study is conducted in the bench-scale cone calorimeter to evaluate the fire risk associated with these materials. Then, micro-scale Thermogravimetric Analysis (TGA) is used to identify the fundamental chemical reactions to be able to confidently interpret the flammability results. Finally, intermediate-scale standard fire tests are conducted to evaluate the applicability of the bench-scale results to realistic fire scenarios. These take the form of modified Lateral Ignition and Flame spread Test (LIFT) and Single Burning Item (SBI) tests to understand flame spread and compartment fires respectively. Finally, a simplified method to combine this knowledge for use in building design is proposed. This method allows the balancing of potential energy benefits with quantified fire performance to achieve the specified goals of the designer. Hemp-lime insulation is a material which has also becoming increasingly popular in the drive towards sustainability. The porous nature of the material means that smouldering combustions are the dominant reaction mode but there is currently no standardised test method for this type of behaviour. Thus, hemp-lime materials also represent an unquantified risk. The work in this thesis defines a simple, accessible and economically viable bench-scale method for quantifying the fire risk associated with rigid porous materials. This is applicable for both downward opposed flow and upward forward flow smoulder propagation conditions. The behaviour is then interpreted using micro-scale thermogravimetric analysis to understand the underlying pyrolysis and oxidation reactions. Designers can utilise this framework to quantify the smouldering risk associated with hemp-lime materials to enable their usage in the built environment. The holistic fire risk assessment performed in this thesis has quantified the behaviour of PCMs and hemp-lime insulation applicable to realistic fire scenarios. The simplified design method empowers designers to be able to realise innovative buildings through fundamental understanding of the fire behaviour of these materials. The outcomes of this thesis allow designers to mitigate the fire risk associated with these materials and achieve optimised engineering solutions. Furthermore, the novel fire testing frameworks provide the economically viable means to assess the fire performance of future PCMs and hemp-lime products which ensures lasting relevance of this research in the future.