Flow Measurement in a Swirl Combustor in Two Cases of With and Without Combustion

The aerodynamic effect of combustion in a swirl type combustor was studies using a flow direction detector probe, a Laser Doppler Velocimetry and a Spark Tracing technique. By the flow direction detector, the reverse flow region inside the recirculation zone was found. The velocity distribution was measured by the Laser Doppler Velocimeter and compared with that of without combustion. When the swirl number of the flow was higher than 0.5, the reverse flow zone was increased by the thermal expansion due to the combustion occurring in this zone. The axial velocity in this zone was also increased by combustion. On the contrary, when the swirl number was lower than 0.5, the reverse flow zone was decreased by the combustion. Flow photographs taken for flow visualization by the Spark Tracing technique showed that the small turbulence in the flow was diminished by the combustion.