Unsteady 3D Flow in a Single-Stage Transonic Fan: Part I — Unsteady Rotor Exit Flow Field Free

Detailed unsteady aerodynamic measurements have been taken in a single-stage transonic fan with a very high stator-hub loading. 2D dynamic yawmeter probes, capable of measuring mean and fluctuating levels of stagnation pressure, static pressure and yaw angle have been traversed at rotor exit, and downstream of the stator along with several types of pneumatic 3D probe. Part I of this paper describes the dynamic yawmeters and their performance, and presents ensemble-averaged stagnation pressure and random stagnation pressure unsteadiness measurements taken at rotor exit. These are used to illustrate the salient features of the rotor flow field, and the effects of compressor aerodynamic loading. Part II presents measurements taken at stator exit.