Technology Development of Fast-Response Aerodynamic Pressure Probes

Abstract

This paper presents and discusses the recent developments on the Fast-Response Aerodynamic Pressure Probe (FRAPP) technology at the Laboratorio di Fluidodinamica delle Macchine (LFM) of the Politecnico di Milano. First, the different geometries developed and tested at LFM are presented and critically discussed: the paper refers to single-sensor or two-sensor probes applied as virtual 2D or 3D probes for phase-resolved measurements. The static calibration of the sensors inserted inside the head of the probes is discussed, also taking into account for the temperature field of application: in this context, a novel calibration procedure is discussed and the new manufacturing process is presented. The dynamic calibration is reconsidered in view of the 15-years’ experience, including the extension to probes operating at different temperature and pressure levels with respect to calibration. As for the probe aerodynamics, the calibration coefficients are discussed and the most reliable set here is evidenced. A novel procedure for the quantification of the measurement uncertainty, recently developed and based on the Montecarlo methodology, is introduced and discussed in the paper.

Effect of clocking on entropy noise generation within an aeronautical high pressure turbine stage

“…By combining acquisitions for multiple rotations around its own axis, the FRAPP is operated as a virtual three-hole probe and provide information on the time-periodic component of the total and static pressure and blade-to-blade flow angle. Full details on the FRAPP technique and its most recent developments can be found in details in [21].…”

Concept Design and Data-Reduction Algorithms for a 20-hole Omnidirectional Probing Sphere

“…They stated that the probe's response time was 10.2 ms, which is still much too slow in a lot of circumstances. Gaetani and Persico [23] presented and discussed the recent developments on the Fast-Response Aerodynamic Pressure Probe technology at the Laboratorio di Fluidodinamica delle Macchine (LFM) of the Politecnico di Milano.…”

Wall-Proximity Effects on Five-Hole Probe Measurements

“…Numerous efforts have been carried out by researchers to further improve the convenience and range of use of 5HPs. For example, Hall [4] offered a 3D-printable open-access probe design that does not need individual calibrations; alternative calibration methods, using several sets of calibration coefficient definitions depending on the flow direction, have been developed that widen the angle range of the probes [5,6]; pressure sensors have been embedded in the probe head itself to perform high-frequency measurements [7]; and traverse processes have been designed that optimise the measurement grid to speed up the traverses [8]. Also, when considering a full assembly comprising a probe and a traversing system, the sizes of interfaces tend to be smaller and safer than those of optical access (a few millimetres versus a few centimetres), making them the preferential choice for the characterisation of confined flows in secluded spaces.…”