Study on the flow and combustion characteristics of an advanced vortex combustor under nonuniform inlet velocity profiles

Nonuniform inlet velocity profiles directly affect the combustor performance. In this study, seven perforated plates with different nonuniformities and peak positions are designed. Numerical simulations are performed to investigate the effect of nonuniform inlet velocity profile on the flow and combustion characteristics of an advanced vortex combustor under atmospheric pressure conditions, with an inlet Mach number of 0.29 and inlet temperatures of 300 K and 800 K. The results are compared with those obtained under uniform inlet velocity conditions. Specifically, the nonuniformity depends only on the perforation ratio, whereas the peak position is determined by the location of the largest hole. As the nonuniformity increases, the total pressure recovery coefficient decreases. In contrast, as the peak position shifts upward, the total pressure recovery coefficient first decreases and then increases. In addition, regardless of increasing nonuniformity or shifting peak position upward, the vapor-phase concentration, combustion efficiency, outlet temperature distribution, and NO emissions all exhibit a trend of first decreasing and then increasing. These findings provide design guidance for the advanced vortex combustor under nonuniform inlet velocity profiles.