Effect of velocity variation at high swirl on axial flow development inside a can combustor

Abstract

The main purpose of this paper is to study the internal flow effect of varying the inlet velocities inside a combustor. The flow field inside the combustor is controlled by the liner shape and size, wall side holes shape, size and arrangement (primary, secondary and dilution holes), and primary air swirler configuration. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore, designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion with low pressure losses. Four various injection velocities from 30m/s to 60m/s with radial vanes angle of 50 degree were used in this analysis to show velocity effect on the internal flow field. The flow behavior was investigated numerically using CFD solver Ansys 14.0. This study has provided the characteristic insight into the flow pattern inside the combustion chamber. Results show that the swirling action is augmented with the increase in the injection velocity, which leads to increase in core reverse flow, thus enhancing mixing of fuel and air in the combustion chamber.