Conventional Probes for the Relative Flow Measurement in a Turbomachinery Rotor Blade Passage

This paper reports the measurement of the relative flow in the rotor blade passages of an axial-flow compressor and an axial-flow inducer using conventional probes such as five-hole, disk, and spherical pitot-static probes. The five-hole probe provides an inexpensive, yet accurate, method of deriving the three-dimensional flow field in a rotor; the disc probe is suitable for the blade boundary-layer measurement; and the pitot-static probe is useful for obtaining the static and stagnation pressures and the total velocity across the rotor passage. Typical data obtained from each of these probes demonstrate the complex nature of the turbomachinery rotor flow. A detailed discussion of various sources of probe errors and methods of estimating these errors is also included.