SWIRL EFFECTS ON DYNAMICS CHARACTERISTICS OF A COAXIAL JET

The reactants are generally injected into the industrial furnaces by jets. An effective method to act on combustion in such systems is to control the way injection jets. The present study concerns the control of an air-flow generated through a coaxial burner. The effects of passive control on a turbulent flow were investigated experimentally. The principal idea consists in adding small obstacles on the outlet side of the burner's annular jet with an aim of increasing the turbulence intensity in the vicinity close to the edge of injection and of having an act on the central flow. The objective of this study consists to study of a swirling flow in a circular pipe and conceiving of a control system significantly improving the mixture on a non-reactive flow in order to apply it to a reactive situation. The various profiles speed for various values of the air-flow injected into the annular tube will be presented in order to propose the effectiveness of our inspecting device in terms of improvement of the mixture between the two jets as well as the mixture with the ambient air. The particle image velocimetry technique has been used to characterize the dynamic field. Results show that the control by adding small obstacles has a considerable effect on the dynamic behavior.