الفهرس 
Layout of Thesis
TEST RIG AND MEASURING DEVICESOnly 14 pages are availabe for public view
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Abstract
An experimental study were carried out to investigate the effect of inserting the annular ribs inside a cylindrical combustion chamber on heat transfer enhancement, combustion and flame stability by using a triple flame burner type which burns LPG in two stages, first with rich mixture and at the end using an excess of air. For this purpose, a test rig is constructed in the combustion laboratory of the Faculty of Engineering of Ain Shams University. The test rig is constructed with facilities to carry out the measurements and experimental work of LPG flame using a triple flame burner, the flow rates are measured by a set of calibrated turbine flow meters with electronic circuits, thermocouples and thermometers were used to measure temperatures ,the heat transfer and firing rate are calculated based on the above measurements. The experimental investigation is performed for two types of ribs (square and triangle) at different axial locations with X/D= 0.667, 2.143, 3.667 and 5.286 with different types of combustion (lean, rich, and stoichiometric) for air to fuel equivalence ratio λ= (1.3) for lean, (0.9) for rich, and (1) for stoichiometric. The effects of changing the rib shape and the axial location on the profile of the heat flux, combustion characteristics and gas analysis through the firing tube are achieved. The results of the present work indicate that: The ribs (square and triangle) have a significant enhancement in heat flux all over X/D positions in all segments. The flame temperature has increased clearly after using square and triangle ribs.
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Triangle rib had superiority over the square one in heat flux with using it at the end of segment (1), (2), (3) because of increasing turbulence by generating of swirl and vortex. Almost triangle rib has a higher flame temperature than the square one in the most positions as a result of increasing turbulence. The highest heat flux with triangle rib at the end of segment (2) in stoichiometric combustion with X/D=2.14. The highest flame temperature with triangle rib at the end of segment (2) in stoichiometric combustion with X/D=2.14. The lowest emissions of CO and NO were at using triangle rib at the end of segment (3) in a lean combustion.