抄録
Pneumatic probes are commonly used to determine the flow vector
as well as the thermodynamic state of the fluid in turbomachinery
applications. The conventional method to measure a flow passage
velocity or pressure field is to move the probe to discrete positions
and to hold a certain settling time before valid data can be
recorded.
This study presents a measurement methodology leading to a reduction
in the required measurement duration of up to 70-90%, depending
on the level of flow field resolution. The approach is based
on the concept of continuously traversing probes as introduced by
Gomes et al. [1]. However, the system model is changed by reducing
the transfer function to a single PT1-behavior. While the experiments
conducted by Gomes et al. [1] were limited to only linear
cascade measurements, the method used here is extended to turbomachinery
applications with highly complex flow structures. The
continuous traverse measurements are validated through a comparison
with conventional discrete measurements that include characteristic
settling time. For this purpose, tests have been performed in
an axial diffuser test rig operated with air and a low pressure steam
turbine. The results obtained with the new approach show a good
match, thus proving the viability of the proposed method for turbomachinery
applications. For future tests, a significant reduction in
measurement time and cost can be achieved.
