2 種類の遠心圧縮機用ディフューザにおける失速抑制効果の比較(流体工学, 流体機械)

The anti-stall effects in two diffusers, a vaned diffuser with fixed small vanes and a low-solidity cascade diffuser, were compared in a centrifugal compressor with suction damper. These diffusers had the same outer diameter. The surge limit flow rate did not differ, however, the stability differed. To clarify the difference of stability, pressure measurement and numerical simulation were carried out. In the vaned diffuser, the flow guided by the small vane pushed back the flow from down stream of throat. This mechanism suggests instability near surge point. In the low-solidity cascade diffuser, there observed no backflow on the whole suction surface. This suggests the more stable character.