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Thermoacoustic instability which stems from the non-linear interactions between heat release and pressure waves in a confined combustion chamber, can create large amplitude pressure oscillations. These oscillations may cause significant damage to the combustor hardware, and even surroundings. Accurate characterization and prediction of such instability is challenging due to its inherent complexities arising from the non-linear nature of the problem.In this thesis, we design a Rijke tube, a device in which self-excited thermoacoustic instabilities can be studied for relatively simple flame geometries. Subsequently, we used the Rijke tube to investigate dynamics of thermoacoustic instability in premixed laminar flame. We focused on the role of burner design on the ensuing instability and flame dynamics by investigating pressure oscillations observed in four different single- and multi-flame burners. We observed that %a single- and seven-flame burner tip using similar flame conditions were experimentally compared, by recording pressure data. The the single-flame burner did not display transition to an unstable state, when the burner was traversed along the length of the Rijke tube, while a seven-flame burner showed various states of instability and multiple bifurcation points. This observation confirms that the increased degree of freedom, arising from the interaction between individual flames in a multi-fame burner, is responsible for the wider dynamics observed.Subsequently, to quantify the dynamics of individual flames and their roles in the ensuing pressure dynamics, a three flame burner, where the flames are located in-line, were studied in details. The Phase Lock Value, Root Mean Frequency, and Power Spectral Density were analyzed for the heat release rates from individual flames and the acoustic pressure. We observed that the center flame possessed stronger synchronization with the pressure. But, the left and right flames shared a few modes (frequencies) of oscillations with the pressure, that were not present in the center flame. This suggests that the dynamics that effect of the individual flames pose varying degrees of influence on the pressure dynamics.An additional experiment was also conducted using an asymmetric three-flame burner, where the flames are located at the tip of an isosceles triangle, using the same flame conditions. This flame showed stronger pressure oscillations, perhaps due to enhanced degrees of interactions between three flames with the symmetric design, and eventually suffered blow-off. These systematic investigations highlights the strong influence of local flame interactions on the observed pressure dynamics, which is relevant for design of multi-nozzle combustors.

peer-reviewed As part of a European Union climate change and energy package that aims to reduce greenhouse gases by 20%, reach 20% penetration of renewable energy, and improve energy efficiency by 20% by 2020, Ireland has committed to generating 40% of its electricity using indigenous renewable sources, primarily wind, by 2020. As wind is an intermittent energy source, a key challenge will be to increase the flexibility of the electricity system in order to maximise yields from the installed wind generation capacity and to minimise curtailment. With the advent of smart grid technologies, substantial focus is being placed on demand side management, or more specifically demand response as a means of achieving the necessary flexibility. In contrast to energy storage which shifts the timing of energy availability, demand response aims to manipulate consumer???s demand to more efficiently use available generation sources. This is typically achieved using suitable financial reward structures; however, it requires the provision of advanced metering and information systems to the consumer. This project examines the suitability of a real-time pricing tariff based on Ireland???s electricity market spot price to determine whether or not the resulting demand flexibility is conducive to increasing the facilitation of wind generated electricity. Demand response is simulated using three load types: a dishwasher, an electric car, and an immersion water heater. As well as optimising in response to price, optimisations in response to wind availability and carbon intensity are examined and their results compared to determine the significance of the yields achieved using price optimisation. Furthermore, yield reductions resulting from the use of imperfect day-ahead prediction data are analysed. Although the results highlight significant benefits, considerable conflicts occur primarily when price optimising thermal loads.

A collection of folklore and local history stories from Faltia (school) (Faltia, Co. Roscommon), collected as part of the Schools' Folklore Scheme, 1937-1938 under the supervision of teacher Thomas Quinn., Weather-Lore / Kenny, Criss -- Local Patron Saint / Flannery, James -- Local Patron Saint / Feehily, Bridget -- Local Patron Saint / Greene, Kathleen -- Local Cures / Finn, Pat -- Local Cures / Feehily, Bridget -- Local Cures / Killeen, Nora -- Fairy Forts / Kenny, Chriss -- Festival Customs / Greene, Kathleen -- Festival Customs / Kenny, Criss -- Festival Customs / Finn, Patrick -- Festival Customs / Flynn, Kathleen -- Festival Customs / Ryan, Kathleen -- Festival Customs / Gaffey, Julia -- Riddles / Mulvey, Mary -- Riddles / Greene, Kathleen -- Riddles / Gaffey, Julia -- Funny Story / Mulvey, May -- Funny Story / Lennon, Kate -- Funny Story / Quirke, Kathleen -- Funny Story / Timulty, Maureen -- Care of Feet / Tumilty, Patrick -- Care of Feet / Quirke, Kathleen -- Care of the Feet / Kelly, James -- Care of the Feet / Finn, Patrick -- Care of the Feet / Feehily, Bridget -- Herbs / Gaffey, Julia -- Herbs / Finn, Patrick -- Herbs / Greene, Kathleen -- Herbs / Greene, Mary -- Herbs / Mulvey, May -- Care of Our Farm Animals / Greene, Kathleen -- Care of Our Farm Animals / Feehily, Bridget -- Care of the Farm Animals / Mulvey, May -- Care of Our Farm Animals / Finn, Patrick -- Buying and Selling / Finn, Patrick -- Buying and Selling / Flannery, Mary -- Buying and Selling / Greene, Michael -- Buying and Selling / Gaffey, Besy -- Buying and Selling / Gaffey, Julia -- Buying and Selling / Feehily, Bridget -- Buying and Selling / Mulvey, May -- Stories of Giants and Warriors / Downey, Teresa -- Churning / Mulvey, May -- Churning / Gaffey, Besy -- Churning / Tumulty, Maureen -- Churning / Downey, Teresa -- Religious Stories / Feehily, Bridget -- Religious Stories / Mulvey, May -- Religious Stories / Downey, Teresa -- Religious Stories / Tumulty, Maureen -- Potato Crop / Greene, Kathleen -- My Home District / Finn, Patrick -- Lore of Certain Days / Finn, Patrick -- Our Holy Wells / Downey, Teresa -- My Home District / Feehily, Bridget -- My Home District / Gaffey, Besy, Supported by funding from the Department of Arts, Heritage and the Gaeltacht (Ireland), University College Dublin, and the National Folklore Foundation (Fondúireacht Bhéaloideas Éireann), 2014-2016.