A NUMERICAL AND EXPERIMENTAL STUDY OF FIVE-HOLE PROBE CALIBRATIONS IN LOW-SPEED FLOWS

This study aims to establish fundamental steps for developing an optimal methodology to enhance experimental probe calibration. Multi-hole pressure probes have been extensively used to measure the airflow around airfoils, wings, and other surfaces in the field of fluid dynamics. Five-hole probes are broadly used in wind tunnel testing and aerodynamic survey to collect data on velocity, pressure distribution, and flow characteristics. These measurements help in understanding the aerodynamic performance of new aircrafts, planes, and aerospace vehicles to improve the efficiency and lower environmental costs, however, the calibration process for these probes conventionally demands considerable effort, time, and cost. The purpose of this study is to leverage advanced instrumentation and measurement techniques to ensure optimal calibration of probes, thereby minimizing data uncertainty and maximizing accuracy. The automated calibration facility for data acquisition secures outstanding repeatability. A computational study determined an optimal probe placement in a calibration jet to read accurate measurements by investigating the region around the probe surface and nozzle. To shorten the calibration time, experiments for finding an optimized measurement incremental step were implemented and discussed comparatively. Experimental calibration maps were generated using non-dimensional pressure coefficients to describe flow characteristics within predetermined flow conditions. The experimental calibration map was assessed by quantitative comparison, and compared to a high-resolution numerical calibration map. This methodology including research findings is expected to facilitate the study for investigating numerical and experimental calibration in subsonic flows by obtaining great insights into advanced calibration from the present study.