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Title: Computational fluid dynamics in industrial and environmental applications
Author: Hassan, Gasser Elhussin Gad Elrab
Awarding Body: University of Leeds
Current Institution: University of Leeds
Date of Award: 2010
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Full text unavailable from EThOS. Thesis embargoed until 01 Oct 2030
In recent years, natural gas has taken over from coal and it has become the second energy source after oil. This is not only because of its economic attractiveness, but also due to environmental concerns. This study is concerned with developing accurate Computational Fluid Dynamics (CFD) numerical models to study two different natural gas combustion systems, namely central heating domestic boilers and thermal cracking furnaces in petrochemical industries, in which the turbulence and the chemical kinetics play a similar role in importance. The first part of the thesis is concerned with developing accurate two-dimensional and three-dimensional CFD models to simulate the premixed flame produced in domestic boilers with a conventional cylindrical premix burner. The second part of the thesis is concerned with developing a three-dimensional CFD model to simulate the turbulent diffusion flame on the fire-side of the radiation section of thermal cracking test furnace coupled with a non-premixed low NO„ floor burner. Although, these two systems produce two different tying of flames, premixed and diffusion, and are used on two different scales in process beating applications, 30 kW and 6 MW, for both of the two systems, the turbulent mixing rate and the chemical reaction rates have comparable values and hence this should be considered in the model. Different combustion models, such as the pre-assumed PDF model with equilibrium chemistry and Eddy Dissipation Concept (EDC) with the detailed GRI 2.11 reaction mechanism, are used to simulate the turbulence-chemistry interactions inside the two combustion systems. Also, The effects of using different turbulence and radiation models and different reaction mechanisms on the accuracy of the predicted results are investigated. For the premixed flame inside domestic boilers, the CFD numerical results are compared with the experimental measurements at different boiler loads to investigate the accuracy of different CFD models. The most accurate validated CFD model is used to investigate the effect of different operating conditions on CO and NO emissions. Furthermore, the design of the 10 kW burner is modified in order to reduce the CO and NO emissions produced from the boiler.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available