Detailed numerical simulation of primary atomization by crossflow under gas turbine engine combustor conditions

Abstract

The present study concerns a detailed numerical simulation of primary atomization by crossflow in the flow of a gas turbine engine combustor. At high Weber numbers, such as in a gas turbine engine, the scale ratio of the atomization phenomenon becomes large, and it is necessary to use a relatively fine grid to obtain reliable results. The present study conducts the first numerical analysis in a gas turbine engine condition with a sufficiently fine grid to give a result that can be discussed reliably, and details of the atomization mechanism are clarified for the first time. In a gas turbine engine combustor, Rayleigh–Taylor (RT) instability dominates at the edge of the liquid column. On the other hand, when the liquid–gas density ratio or the Weber number are low, RT instability is not significant. The process of ligament formation changes depending on the dominant instability mechanism, and the ligaments becomes smaller when RT instability is dominant. Also, the size distribution of the atomized droplets clearly changes when RT instability becomes significant.