On Fast-Response Probes: Part 1—Technology, Calibration, and Application to Turbomachinery

Abstract

A system for fast-response probe measurements in turbomachine flows has been developed and tested. The system has been designed for 40 kHz bandwidth and used with various in-house built probes accommodating up to four piezoresistive pressure transducers. The present generation of probes works accurately up to several bar pressure and 120°C temperature. The probes were found to be quite robust. The use of a miniature pressure transducer placed in the head of a probe showed that a precise packaging technique and a careful compensation of errors can considerably improve the accuracy of the pressure measurement. Methods for aerodynamic probe calibration and off-line data evaluation are briefly presented. These aimed, e.g., in the case of a four-hole probe, at measuring the velocity fluctuations as characterized by yaw, pitch, total pressure, and static pressure and at deriving mean values and spectral or turbulence parameters. Applications of the measuring system to turbomachinery flow in a radial compressor and to a turbulent pipe flow demonstrate the performance of the measuring system.

Time-resolved measurements with fast-response probes and laser Doppler velocimetry at the impeller exit of a centrifugal compressor: a comparison of two measurement techniques

“…The configuration of the system used for the measurements presented herein has been described in detail in reference [13]. A more general overview has been given in reference [14]. In the following the main features of the system will be described briefly.…”

Strömungsuntersuchung in hydrodynamischen Wandlern: Zusammenspiel von Messung und Rechnung

“…[27] ffir ihre Str6mungsmessungen eine Ffinf-Loch-Sonde ein, bei der die Drucksensoren im Sondenschaft (Q = 9.14 ram) angeordnet waren. Besonders hervorzuheben sind die Arbeiten yon Gossweiler [17,18,19], in denen die Entwicklung yon Ein-Sensor-und Vier-Sensor-Sonden mit kleinsten Abmessungen sowie die Eignung yon Siliziumhalbleitern for die instation/ire Str6mungsmessung beschrieben werden.…”

Technology Development of Fast-Response Aerodynamic Pressure Probes

“…The FRAPP concept comes from the combination of fast-response pressure transducers, typically of the piezoresistive kind, with aerodynamic directional pressure probes. The transducers can be flush-mounted on the probe head [14], enhancing the frequency response despite fragility; in other examples [6,[15][16][17], the researchers preferred to embed the transducers within the probe head to enhance the probe strength. Excellent reviews on the early stages of FRAPP development can be found in [18][19][20].…”