The trench casing often occurs in axial compressors due to the casing rubbing or casing treatment. However, the effect of the trench casing on the aerodynamic performance of axial compressors has not been fully understood, especially at different rotating speeds. Therefore, we numerically investigate the effect of the trench casing on a transonic compressor at two rotating speeds. A detailed comparison of overall performance and flow characteristics has been performed. The results show that the trench configurations slightly increase the total pressure ratio and mass flow rate near the choking condition but reduce the total pressure ratio and adiabatic efficiency at small mass flow rates. The largest efficiency reduction of the parallel trench (PT) and within trench (IT) cases is more than 1%, which is located at the mid blade passage near 90% span. The effect of the trench configurations on the stall margin is different for the two rotating speeds. At 100% rotating speed, the outside trench (OT) and IT cases improve the stall margin by 2.8% and 1.1%, respectively, but the PT case decreases the stall margin by 1.3% due to the increased blockage in the core region of the tip leakage vortex. At 80% rotating speed, the stall margin of the trench configurations becomes worse. Because of the increased blockage of the mid blade passage, the PT and IT cases decrease the stall margin by 2.9% and 2.1%, respectively. Though there are some differences in the flow characteristics of the trench configurations at the two rotating speeds, the change of the stall margin always depends on the blockage near the tip region. This work can contribute to further understanding the impact of the trench casing on axial compressors.
邓贺方，夏凯龙，滕金芳，羌晓青，朱铭敏，卢少鹏
. Performance Effect of Trench Casing on a Transonic Compressor at Different Rotating Speeds[J]. Journal of Shanghai Jiaotong University(Science), 2024
, 29(6)
: 1151
-1160
.
DOI: 10.1007/s12204-022-2541-3
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