Characterization of Side-Dump Combustor Flowfield Using Particle Image Velocimetry

Abstract

An experimental study was carried out to investigate the instantaneous flowfield in a side-dump combustor using particle image velocimetry and examine the systematic effects of geometric variations (inlet angle and dome height) on the mean flowfield and the recirculation zones. The instantaneous velocity fields showed that the recirculation zones in the combustor consisted of large-scale and small-scale vortices, and the flow pattern might change periodically due to the oscillation of two inlet jets. The mean velocity fields indicated that as the inlet angle increased, the height of the secondary recirculation zone and the maximum reverse mass flow rate at transport into the primary recirculation zone increased almost linearly. The results also indicated that there was an optimum dome height for each inlet angle even though the dome height did not significantly affect the flowfield downstream of the combustor inlet. The values of the maximum reverse mass flow rate in the secondary recirculation zone were equivalent to those in the primary recirculation zone, so the secondary recirculation zone was believed to be as important as the primary recirculation zone for flame stabilization.