Experimental investigation of flow field characteristics in a mixed-flow trapped vortex combustor

Abstract

This paper describes an experimental investigation of flow field characteristics of a conceptual trapped vortex combustor (TVC). It is the first time that the novel TVC is evaluated for turboshaft engine that utilizes a single cavity to provide flame stabilization. A Particle Image Velocimetry (PIV) has been applied to observe the effect of inlet air velocity on the flow field patterns and velocity profiles in a three-dome sector test rig under atmospheric pressure and room temperature. Experiment results show that all average flow fields were stable and self-similar in the cavity in varying operating conditions. A counter-rotating vortex pair was created and safely locked in the cavity along the mainstream plane. As the inlet air velocity increased to 42 m/s, a third vortex was generated. A single dominant stream-wise vortex was spanned the entire cavity along the strut plane. There was a shift in the vortex center location of the strut plane and mainstream plane at the same inlet air velocity, which indicates the three dimensional nature of the flow field in the cavity. Further analysis of velocity profiles showed that flow fields remained stable. The velocity of the vortex downstream zone in the cavity was higher than that in the countercurrent zone.