Investigation of the Effects of Airfoil-probes on the Aerodynamic Performance of an Axial Compressor

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 stream-wise 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.