Development of a High-Resolution Computational Model for Investigating the Flow Around and Inside Traditional Five-Hole Probes

Pressure probes are amongst the most used instruments for measuring pressure and velocities in fluid flows. Five-hole probes have five holes at the tip aligned with the flow, which are calibrated for various speeds and angles in both the pitch and yaw directions in order to generate a calibration map, then used for calculating flow velocities and angles when the probe is subject to the flow of study. Real flows may include particulates, such as dirt, sand, combustion residues, as well as different gas compositions, which may affect the performance of the probe by potentially clogging one of more of the holes, for example. In this work, numerical analyses of a hemispherical straight probe in pre-determined flows are performed to investigate the development of flow over the surface and internally to the probe channels. A commercial software is used to analyze the region near the head of the probe, where there is low turbulence and a favorable pressure gradient. The present work shows the characteristics of the flow development inside the entrance of the channels, furthermore, bringing insight into the impact of the channels on the flow around the probe head and the differences in the pressure data depending on pitch and yaw angles. Developing a highresolution computational model will lead us to perform further computational studies to investigate the influence of different build parameters of the probe (such as head shape, surface roughness and positioning of holes) involving in the quality of the acquired data. It is expected that these results will bring great insight on methodology to study the flow behavior around multi-hole probes and correlations between acquired data and build parameters of the probe in airflow in addition to creating a powerful tool to decrease calibration costs by offering a computational alternative.