Measurements in an annular combustor-diffuser system

Results of three-component Laser Doppler Velocimeter (LDV) measurements in an annular combustor-diffuser system are presented in this paper. The LDV measurements were made at several locations in the prediffuser and dump regions of the combustor-diffuser test rig for three different inlet velocity profiles. The prediffuser average inlet Mach number was maintained at 0.305 during these tests. The LDV data are compared with predictions obtained from a boundary-fitted, two-dimensional elliptic analytical model. The agreement between the LDV data and the predicted results is very good for mean velocities. However, measured turbulence intensities are higher than the predicted values in the region adjacent to the prediffuser walls.