A Study on Combustion Field in a Slit Burner by PIV/OH-PLIF Simultaneous Technique

Abstract

Diffusion combustion (non-premixed combustion), which is formed by supplying fuel and oxidizer separately, is used in many practical combustors. However, we cannot control the flame temperature, because the diffusion flame is formed in the region at the stoichiometric condition. Hence, it is difficult to reduce the combustion products such as soot and NOx. So far, we have investigated combustion field in a triple port burner. In the triple port burner, since there are two boundaries of fuel and air, two flames are formed. Then, by changing the flow condition, four flame configurations are observed, which are, (i) attached flames, (ii) inner lifted/outer attached flames, (iii) inner attached/outer lifted flames, (iv) twin lifted flames. For further study, we investigated the slit burner which has air nozzles on both sides of a fuel nozzle, which is similar to the triple port burner. In experiments, we measured the flow field and flame structure by PIV/OH-PLIF simultaneous measurement. We also investigated hysteresis characteristic of the lifted flame in the slit burner.