This paper discusses flow measurement results both upstream and downstream of a transonic annular turbine nozzle with a nonuniform pitch. The downstream measurements are performed in the plane, where the leading edge of the rotor is located in the gas turbine.
The experiments were performed using total pressure probes and static wall pressure taps.
This type of nonuniformity creates a different behavior of the flow field both upstream and downstream of the blades. The effects on the wakes and on the inviscid flow are discussed separately.
The mean velocities show a strong sensitivity to the changes of the pitch, which is identified as a potential flow effect by using a simple vortex model.