In order to investigate the effects of probe support on the stall characteristics of micro compressors, an experiment was carried out on a large-scale low-speed research compressor according to the principle of geometric similarity. A cylindrical probe support intruding to 50% blade span was mounted at 50% chord upstream from the rotor blade leading edge. The static pressure rise characteristic of the compressor is measured, with and without the probe support respectively. The dynamic compressor behavior from pre-stall to full stall was also measured. The results indicate that the stability margin of the compressor is lowered after installing the probe support. The stall inception is aroused by modal wave disturbances. The disturbances developed into two stall cells smoothly before installing the probe support, while the disturbances first developed into a single stall cell then splitting into two stall cells after installing the probe support. The presence of probe support lowers the initial intensity of the rotating stall of the compressor, while it doesn't alter the intensity of the rotation stall after the compressor enters into full stall.
In order to investigate the effects of the airfoil-probes on the aerodynamic performance of an axial compressor,a numerical simulation of 3D flow field is performed in a 1.5-stage axial compressor with airfoil-probes installed at the stator leading-edge(LE).The airfoil-probes have a negative influence on the compressor aerodynamic performance at all operating points.A streamwise vortex is induced by the airfoil-probe along both sides of the blade.At the mid-operating point,the vortex is notable along the pressure side and is relatively small along the suction side(SS).At the near-stall point,the vortex is slightly suppressed in the pressure surface(PS),but becomes remarkable in the suction side.A small local-separation is induced by the interactions between the vortex and the end-wall boundary layer in the corner region near the hub.That the positive pitch angle of the airfoil-probe at 6.5% span is about 15° plays an important role in the vortex evolution near the hub,which causes the fact that the airfoil-probe near the hub has the largest effects among the four airfoil-probes.In order to get a further understanding of the vortex evolution in the stator in the numerical simulation,a flow visualization experiment in a water tunnel is performed.The flow visualization results give a deep insight into the evolution of the vortex induced by the airfoil-probe.
