EXPERIMENTAL AND THEORETICAL STUDY ON THE FLAME STABILIZATION BY RECIRCULATION BEHIND A BLUFF-BODY.

Document Type : Original Article

Author

Lecturer, Department of Mechanical Power Engineering, Mansoura University, El-Mansoura, Egypt.

Abstract

An experimental investigation and analytical description have been carried out on the flame stabilization by recirculation behind a bluff-body flame holders. The blowout limits of flames and the length of the recirculation zone have been investigated for cylinderical and spherical bluff-body flame holders. Also, measurements of the influence of the flame holder geometry on the lean blowout limits as well as on the rich blowout limits have been carried out.
In the theoretical study, a two-dimensional flow model to describe the mechanism of the flame stabilization by recircul-ation behind a bluff body has been developed. In this model, the process of flame stabilization is governed by the balance between the rates of turbulent mixing and chemical reactions in the shear layer at the recirculation zone boundary. The predicted blowout limits of flames have shown a qualitatively agreement with the observed ones.