Unsteady Three-Dimensional Turbine Aerodynamics

Abstract

High response aerodynamic measurements were made in a large-scale, axial, flow turbine model to study the unsteadiness and three dimensionality of the flow. High response velocity vector and total pressure data were acquired. A comparison was made of the results of phase lock averaging both raw and reduced data (voltages and velocities). The velocity vector measurements showed that there were strong radial flows present as well as significant periodic changes in the flow field due to relative rotor and vane positions. Random, periodic, and total unsteadiness levels were computed from the instantaneous and phase-lock-averaged velocity data. Time-averaged data were compared with an inviscid two-dimensional calculation. A comparison was also made of time-averaged total pressure measurements obtained from high-response and low-response (steady-state) probes.