الفهرس 
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Abstract
Many practical combustion systems are based on the mode of partially premixed flames where the interaction between lean and rich pockets improves the flame stability. In our recent work a highly stabilized concentric flow conical nozzle burner has been designed and developed for partially premixed flames. The stabilization characteristics are very much affected by the degree of partial premixing and the burner nozzle cone angle. Several flow field, temperature and OH radical measurements were conducted outside the cone. In the present work a quartz cone is used for flow visualization inside the cone. So, the aim of the present work is to study the stabilization mechanism inside the cone based on three dimensional measurements of the flow field and temperature field. So, the stability of turbulent partially premixed flames of concentric flow conical nozzle burner based on the near region three dimensional flow fields has been investigated and presented in this thesis. Five turbulent partially premixed flames have been investigated at Reynolds numbers range between 8.3×10Pand 14.5 ×10P and equivalence ratio ranges between 2.5 and 4The turbulent flow field inside and outside the conical quartz nozzle were obtained using a three-dimensional PIV system. The temperature field of selected flames was investigated using fine wire thermocouple. The flow field at the near region inside the cone shows a recirculation zone suggesting air entrainment along the cone wall. This stream of air is likely to be heated by the flame and thus improves the flame stability Thus, the stabilization mechanism of the conical nozzle burner is mainly affected by the flow pattern inside the cone. This flow field structure improves the stability significantly as compared to similar partially premixed flames without cone.