Injector-injector interactions on the flow field, spray characteristics, and subsequent flame pattern in an annular combustor

In this paper, the injector-injector flow field, spray and flame patterns are investigated experimentally in an annular combustor under various mair and mfuel. The results show that the adjacent swirling jets have different velocity mangnitude on the central annular plane due to the curvature of the annular combustor. It can lead to a “deflection jet” instability and subquently switch on a periodic “wide-narrow-wide” CTRZ flow that does not evolve in time. Different bulk velocity airflow will not change the periodic CTRZ arrangement but the vortex structure inside the CTRZ. The spray and flame patterns are significantly impacted by the injector-injector flow field. The “rich fuel” region is consistent with the flame morphology. Both of their sizes rapidly decrease as the bulk velocity increases. Periodicity did not appear in spray and flame due to the weak recirculation and dispersed fuel downstream in low bulk velocity conditions. Under high bulk velocity, stronger recirculation air makes the shape of the spray and flame consistent with CTRZ. The effect of the periodic flow field on spray and flame becomes more apparent.