WAKE MIXING AND PERFORMANCE OF A COMPRESSOR CASCADE WITH CRENULATED TRAILING EDGES

Trailing-edge crenulations have been shown to enhance velocity recovery (wake dissipation) and to decrease total pressure losses in the blade wakes downstream of a low-aspect ratio linear compressor cascade. A new study was performed to determine the influence of trailing-edge crenulations on outlet flow in the presence of varied inlet flow conditions. Two levels of inlet flow turbulence intensity (about 0.15 and 3%) were combined with sidewall boundary-layer removal at the cascade inlet (on or off) to provide four test conditions. Results from blades with large and small crenulations were compared with unmodified blades. For each test condition, a reduction of 10-20% in both velocity variance (enhanced wake mixing) and total pressure loss was observed in the outlet flow with the crenulated blades, while a slight decrease in turning angle was also observed.