An experimental study of turbulent flow in attachment jet combustors by LDV

Flame stabilization in attachment jet combustors is based on the existence of the high temperature recirculation zone, provided by the Coanda effect of an attachment jet. The single attachment jet in a rectangular channel is a fundamental form of this type of flow. In this paper, the detailed characteristics of turbulent flow of a single attachment jet were experimentally studied by using a 2-D LDV. The flowfield consists of a forward flow and two reverse flows. The forward one is composed of a curved and a straight section. The curved section resembles a bent turbulent free jet, and the straight part is basically a section of turbulent wall jet. A turbulent counter-gradient transport region exists at the curved section. According to the results, this kind of combustor should have a large sudden enlargement ratio and not too narrow in width. Project supported by the National Natural Science Foundation of China.