Basic considerations concerning the construction and usage of multiple hot-wire probes for highly turbulent three-dimensional flows

Abstract

The authors discuss the use of multiple hot-wire probes in turbulent three-dimensional flows with the aid of a graphical analysis. It is shown that hot-wire sensors can be used to measure all three components of the velocity vector as long as its direction lies within the acceptability range, which can be extended to a hemisphere if a probe with at least four wires is used. The detection of flow reversal is, however, not possible with any number of simple wire sensors. A computer-aided calibration and data reduction method for a four-wire probe is described. Test measurements in an axisymmetric free jet prove the applicability of the method.