THE EFFECT OF THE PRECESSING VORTEX CORE ON COMBUSTION IN A SWIRL BURNER

This paper examines the fundamental characteristics of a 2 MW swirl bu rner/furnace system and in particular the excitation of the Precessing Vortex Core (PVC) in diffusion controlled combustion with natural gas being introduced axially on the axis of symmetry. Previous studies ha ve indicated that under such conditions the PVC is virtually undetecta ble. The phenomena was investigated via phase averaged LDA and fine wi re thermocouple measurements. The PVC influence is shown to extend ove r virtually all the furnace volume. A processing jet like structure of high velocity is created in which combustion is limited and temperatu res are low. This region is responsible for the very high rates of mix ing found in such systems. Clear relevance to practical industrial sys tem is indicated.