Mixing characteristics of kerosene with different equivalence ratios at different pulse frequencies in a supersonic combustor

The pulsed jet enhances the mixing and combustion performance of a scramjet. The three-dimensional Reynolds- Averaged Navier-Stokes equations are employed to examine the mixing characteristics of kerosene at varying equivalence ratios and pulsed frequencies. The mixing and combustion performance resulting from combinations of three pulse frequencies and three equivalence ratios are compared. The results show that the mixing efficiency and combustion efficiency at the outlet are basically same at different pulse frequencies for the same equivalence ratio. Nevertheless, the mixing and combustion efficiencies at the outlet decrease with increasing equivalence ratio. At a pulsed frequency of 50 Hz, the length of high mass fraction fuel is shorter than other frequencies, resulting in higher mixing efficiency in the combustor, particularly at equivalence ratios of 0.3 and 0.5. In addition, an increase in the ER is not conducive to the complete combustion of kerosene. At an equivalence ratio of 0.5, some kerosene will still be expelled from the combustor without undergoing combustion.