Velocity Characteristics of Isothermal and Combusting Flows in a Model Combustor

Mean and rms values of the axial and swirl velocity components obtained by a laser Doppler anemometer in a model can-type gas turbine combustor under isothermal and combusting flow conditions are reported. The results show that the combustor swirl is characterised by a solid body rotation near the axis and a free vortex flow in regions close to the combustor wall. Combustion strengthens and contracts the primary vortex, accelerates the flow in stream-wise direction and increases the rms of velocity fluctuations. Although the effect of air-fuel ratio on velocity characteristics is relatively weak in the primary zone where the interaction of fuel momentum with the swirler flow causes some changes in primary vortex structure, it becomes steadily more pronounced with downstream distance.