Flow dynamics in low aspect ratio dump combustor

Abstract

This paper reports an experimental investigation of the flow field inside a low aspect ratio dump combustor. The length of the combustor studied was less than the reattachment length for the separated flow. The exit of the combustor is tapered which supports the flow reversal from the exit section. The flow field behaviour in the combustor is evaluated from pressure and velocity measurement studies. The velocity, stream function and pressure distribution inside the combustor are used to elucidate the presence of recirculation and flow reversal from the exit section of the combustor for different Reynolds numbers. A small variation in Urms velocity was observed in axial direction while in the radial direction it was quite high. Two recirculation zones are recognized and the strength of the recirculation was seen to increase with flow Reynolds number. The turbulence intensity in the recirculation and shear layer zone was seen to be higher than the potential core.

Keywords

• Dump combustor
• Flow dynamics
• Circulation
• Turbulence
• Stream function